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• Challenges of Serverless Deployment in Edge-MEC-Cloud Nguyen, TrungKien; Loh, Frank; Hoßfeld, Tobias in KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks 2023 (2023).
  • [ BibTeX ]
  • [ EndNote ]
  @inproceedings{info3-inproceedings-2023-6, author = {Nguyen, TrungKien and Loh, Frank and Hoßfeld, Tobias}, booktitle = {KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks 2023}, keywords = {sys:hidden:inproceedings}, title = {Challenges of Serverless Deployment in Edge-MEC-Cloud}, year = 2023 }

  %0 Conference Paper %1 info3-inproceedings-2023-6 %A Nguyen, TrungKien %A Loh, Frank %A Hoßfeld, Tobias %B KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks 2023 %D 2023 %T Challenges of Serverless Deployment in Edge-MEC-Cloud
• On the Validity of Credit-Based Shaper Delay Guarantees in Decentralized Reservation Protocols Maile, Lisa; Voitlein, Dominik; Grigorjew, Alexej; Hielscher, Kai-Steffen J.; German, Reinhard in 31st International Conference on Real-Time Networks and Systems (2023).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Resource reservation is a fundamental mechanism for ensuring quality of service in time-sensitive networks, which can be decentralized by using reservation protocols. In the Ethernet technology Time-Sensitive Networking, this has been proposed in conjunction with the Credit-Based Shaper. For the reservation, the standards assume a maximum worst-case latency bound at each hop. However, we will show through formal analysis and simulation that these worst-case latency bounds are not safe. To face this, we propose an extension to the current standards to allow the reservation of time-sensitive traffic with reliable latency guarantees. The effectiveness of our approach is demonstrated through simulations of both synthetic and industrial networks. Finally, by providing additional information about neighboring devices, we could further increase the maximum reservable traffic by up to 20% in our test cases.

  @inproceedings{info3-inproceedings-2023-5, abstract = {Resource reservation is a fundamental mechanism for ensuring quality of service in time-sensitive networks, which can be decentralized by using reservation protocols. In the Ethernet technology Time-Sensitive Networking, this has been proposed in conjunction with the Credit-Based Shaper. For the reservation, the standards assume a maximum worst-case latency bound at each hop. However, we will show through formal analysis and simulation that these worst-case latency bounds are not safe. To face this, we propose an extension to the current standards to allow the reservation of time-sensitive traffic with reliable latency guarantees. The effectiveness of our approach is demonstrated through simulations of both synthetic and industrial networks. Finally, by providing additional information about neighboring devices, we could further increase the maximum reservable traffic by up to 20% in our test cases.}, author = {Maile, Lisa and Voitlein, Dominik and Grigorjew, Alexej and Hielscher, Kai-Steffen J. and German, Reinhard}, booktitle = {31st International Conference on Real-Time Networks and Systems}, keywords = {can}, month = 6, title = {On the Validity of Credit-Based Shaper Delay Guarantees in Decentralized Reservation Protocols}, year = 2023 }

  %0 Conference Paper %1 info3-inproceedings-2023-5 %A Maile, Lisa %A Voitlein, Dominik %A Grigorjew, Alexej %A Hielscher, Kai-Steffen J. %A German, Reinhard %B 31st International Conference on Real-Time Networks and Systems %D 2023 %T On the Validity of Credit-Based Shaper Delay Guarantees in Decentralized Reservation Protocols %X Resource reservation is a fundamental mechanism for ensuring quality of service in time-sensitive networks, which can be decentralized by using reservation protocols. In the Ethernet technology Time-Sensitive Networking, this has been proposed in conjunction with the Credit-Based Shaper. For the reservation, the standards assume a maximum worst-case latency bound at each hop. However, we will show through formal analysis and simulation that these worst-case latency bounds are not safe. To face this, we propose an extension to the current standards to allow the reservation of time-sensitive traffic with reliable latency guarantees. The effectiveness of our approach is demonstrated through simulations of both synthetic and industrial networks. Finally, by providing additional information about neighboring devices, we could further increase the maximum reservable traffic by up to 20% in our test cases.
• Explainable Data-Driven QoE Modelling using XAI Wehner, Nikolas; Seufert, Anika; Hoßfeld, Tobias; Seufert, Michael in 15th International Conference on Quality of Multimedia Experience (QoMEX) (2023).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Data-driven QoE modelling using Machine Learning (ML) allows to reduce the modelling bias and to continuously integrate new QoE results into the QoE model, which can improve its generalizability. The downside is that the majority of ML models are black-box models, which prevent to obtain insights about QoE influence factors and their fundamental relationships that are highly relevant for researchers and providers of services and networks. However, recent advances in the field of eXplainable Artificial Intelligence (XAI) resolve these issues. Thus, XAI allows to benefit from data-driven QoE modelling to obtain generalizable QoE models, and at the same time to understand what QoE factors are relevant and how they affect the QoE score. In this work, we showcase the feasibility of explainable data-driven QoE modelling for video streaming, since video streaming QoE has been well researched, and thus, allows us to validate our results. Finally, we discuss opportunities and challenges of deploying XAI for QoE modelling.

  @inproceedings{info3-inproceedings-2023-4, abstract = {Data-driven QoE modelling using Machine Learning (ML) allows to reduce the modelling bias and to continuously integrate new QoE results into the QoE model, which can improve its generalizability. The downside is that the majority of ML models are black-box models, which prevent to obtain insights about QoE influence factors and their fundamental relationships that are highly relevant for researchers and providers of services and networks. However, recent advances in the field of eXplainable Artificial Intelligence (XAI) resolve these issues. Thus, XAI allows to benefit from data-driven QoE modelling to obtain generalizable QoE models, and at the same time to understand what QoE factors are relevant and how they affect the QoE score. In this work, we showcase the feasibility of explainable data-driven QoE modelling for video streaming, since video streaming QoE has been well researched, and thus, allows us to validate our results. Finally, we discuss opportunities and challenges of deploying XAI for QoE modelling.}, address = {Ghent, Belgium}, author = {Wehner, Nikolas and Seufert, Anika and Hoßfeld, Tobias and Seufert, Michael}, booktitle = {15th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ucn}, month = 6, title = {Explainable Data-Driven QoE Modelling using XAI}, year = 2023 }

  %0 Conference Paper %1 info3-inproceedings-2023-4 %A Wehner, Nikolas %A Seufert, Anika %A Hoßfeld, Tobias %A Seufert, Michael %B 15th International Conference on Quality of Multimedia Experience (QoMEX) %C Ghent, Belgium %D 2023 %T Explainable Data-Driven QoE Modelling using XAI %X Data-driven QoE modelling using Machine Learning (ML) allows to reduce the modelling bias and to continuously integrate new QoE results into the QoE model, which can improve its generalizability. The downside is that the majority of ML models are black-box models, which prevent to obtain insights about QoE influence factors and their fundamental relationships that are highly relevant for researchers and providers of services and networks. However, recent advances in the field of eXplainable Artificial Intelligence (XAI) resolve these issues. Thus, XAI allows to benefit from data-driven QoE modelling to obtain generalizable QoE models, and at the same time to understand what QoE factors are relevant and how they affect the QoE score. In this work, we showcase the feasibility of explainable data-driven QoE modelling for video streaming, since video streaming QoE has been well researched, and thus, allows us to validate our results. Finally, we discuss opportunities and challenges of deploying XAI for QoE modelling.
• Traffic-Adaptive Scheme for SDN Control Plane with Containerized Architecture AnhKhoa, Dang; TrungKiem, Nguyen; TrungKien, Nguyen; NgocTuan, Nguyen; Huu Thanh, Nguyen in 2023 17th International Conference on Ubiquitous Information Management and Communication (IMCOM) (2023).
  • [ Abstract ]
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  Software-Defined Networking (SDN) is gaining attention for its flexibility in programmability. It enhances network configuration and provides global visibility for administrators via a single interface. However, the centralized nature of SDN exposes many issues in scalability and resiliency. In this paper, with the advent of cloud computing, we present a containerized architecture capable of fast scaling up and down based on traffic load for SDN control plane. With our novel traffic-adaptive algorithm, the results show that the proposed system is able to fit performance with high incoming new-flow requests and scale down underused controllers for resource efficiency.

  @inproceedings{info3-inproceedings-2023-3, abstract = {Software-Defined Networking (SDN) is gaining attention for its flexibility in programmability. It enhances network configuration and provides global visibility for administrators via a single interface. However, the centralized nature of SDN exposes many issues in scalability and resiliency. In this paper, with the advent of cloud computing, we present a containerized architecture capable of fast scaling up and down based on traffic load for SDN control plane. With our novel traffic-adaptive algorithm, the results show that the proposed system is able to fit performance with high incoming new-flow requests and scale down underused controllers for resource efficiency.}, author = {AnhKhoa, Dang and TrungKiem, Nguyen and TrungKien, Nguyen and NgocTuan, Nguyen and Huu Thanh, Nguyen}, booktitle = {2023 17th International Conference on Ubiquitous Information Management and Communication (IMCOM)}, keywords = {sys:hidden:inproceedings}, month = 1, title = {Traffic-Adaptive Scheme for SDN Control Plane with Containerized Architecture}, year = 2023 }

  %0 Conference Paper %1 info3-inproceedings-2023-3 %A AnhKhoa, Dang %A TrungKiem, Nguyen %A TrungKien, Nguyen %A NgocTuan, Nguyen %A Huu Thanh, Nguyen %B 2023 17th International Conference on Ubiquitous Information Management and Communication (IMCOM) %D 2023 %T Traffic-Adaptive Scheme for SDN Control Plane with Containerized Architecture %X Software-Defined Networking (SDN) is gaining attention for its flexibility in programmability. It enhances network configuration and provides global visibility for administrators via a single interface. However, the centralized nature of SDN exposes many issues in scalability and resiliency. In this paper, with the advent of cloud computing, we present a containerized architecture capable of fast scaling up and down based on traffic load for SDN control plane. With our novel traffic-adaptive algorithm, the results show that the proposed system is able to fit performance with high incoming new-flow requests and scale down underused controllers for resource efficiency.
• Moving Down the Stack: Performance Evaluation of Packet Processing Technologies for Stateful Firewalls Dietz, Katharina; Gray, Nicholas; Wolz, Manuel; Lorenz, Claas; Hoßfeld, Tobias; Seufert, Michael in 34th IEEE/IFIP Network Operations and Management Symposium (NOMS) (2023).
  • [ BibTeX ]
  • [ EndNote ]
  @inproceedings{info3-inproceedings-2023-2, address = {Miami, Florida}, author = {Dietz, Katharina and Gray, Nicholas and Wolz, Manuel and Lorenz, Claas and Hoßfeld, Tobias and Seufert, Michael}, booktitle = {34th IEEE/IFIP Network Operations and Management Symposium (NOMS)}, keywords = {ucn}, month = 5, title = {Moving Down the Stack: Performance Evaluation of Packet Processing Technologies for Stateful Firewalls}, year = 2023 }

  %0 Conference Paper %1 info3-inproceedings-2023-2 %A Dietz, Katharina %A Gray, Nicholas %A Wolz, Manuel %A Lorenz, Claas %A Hoßfeld, Tobias %A Seufert, Michael %B 34th IEEE/IFIP Network Operations and Management Symposium (NOMS) %C Miami, Florida %D 2023 %T Moving Down the Stack: Performance Evaluation of Packet Processing Technologies for Stateful Firewalls
• Discrete-Time Analysis of Multi-Component Queuing Networks under Renewal Approximation Geißler, Stefan; Lange, Stanislav; Hasslinger, Gerhard; Tran-Gia, Phuoc; Hoßfeld, Tobias in 34th International Teletraffic Congress (ITC). Shenzhen, China (2023).
  • [ BibTeX ]
  • [ EndNote ]
  @inproceedings{info3-inproceedings-2023-1, author = {Geißler, Stefan and Lange, Stanislav and Hasslinger, Gerhard and Tran-Gia, Phuoc and Hoßfeld, Tobias}, booktitle = {34th International Teletraffic Congress (ITC). Shenzhen, China}, keywords = {sys:hidden:inproceedings}, month = 9, title = {Discrete-Time Analysis of Multi-Component Queuing Networks under Renewal Approximation}, year = 2023 }

  %0 Conference Paper %1 info3-inproceedings-2023-1 %A Geißler, Stefan %A Lange, Stanislav %A Hasslinger, Gerhard %A Tran-Gia, Phuoc %A Hoßfeld, Tobias %B 34th International Teletraffic Congress (ITC). Shenzhen, China %D 2023 %T Discrete-Time Analysis of Multi-Component Queuing Networks under Renewal Approximation
• Serverless Computing Lifecycle Model for Edge Cloud Deployments Nguyen, TrungKien; Loh, Frank; Nguyen, Tung; Doan, Duong; Huu Thanh, Nguyen; Hoßfeld, Tobias in IEEE International Conference on Communications 2023 - GreenNet Workshop (2023).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Serverless computing is a new cloud computing execution model. It offers little operational and administrative overhead, function activation on-demand, and significantly reduced resource consumption. For that reason, it is studied heavily in recent literature by means of handling incoming traffic, applicability for different tasks, and overall performance. Especially the introduction of states, where functionality is kept in CPU or memory can improve performance significantly. However, an in-depth analysis of the resource demand by among others, CPU and memory usage, latency, and energy consumption is still a blank spot in literature. To this end, we propose a serverless lifecycle model with intermediate states and deploy an image processing test setup in the edge cloud to test it. Furthermore, we measure important resource metrics of all states and state transitions of the model. This helps us to answer the question, whether keeping functions available in specific states of a serverless computing instance can improve performance without massive negative influence on the resource requirements.

  @inproceedings{info3-article-2023-4, abstract = {Serverless computing is a new cloud computing execution model. It offers little operational and administrative overhead, function activation on-demand, and significantly reduced resource consumption. For that reason, it is studied heavily in recent literature by means of handling incoming traffic, applicability for different tasks, and overall performance. Especially the introduction of states, where functionality is kept in CPU or memory can improve performance significantly. However, an in-depth analysis of the resource demand by among others, CPU and memory usage, latency, and energy consumption is still a blank spot in literature. To this end, we propose a serverless lifecycle model with intermediate states and deploy an image processing test setup in the edge cloud to test it. Furthermore, we measure important resource metrics of all states and state transitions of the model. This helps us to answer the question, whether keeping functions available in specific states of a serverless computing instance can improve performance without massive negative influence on the resource requirements.}, author = {Nguyen, TrungKien and Loh, Frank and Nguyen, Tung and Doan, Duong and Huu Thanh, Nguyen and Hoßfeld, Tobias}, booktitle = {IEEE International Conference on Communications 2023 - GreenNet Workshop}, keywords = {sys:hidden:inproceedings}, title = {Serverless Computing Lifecycle Model for Edge Cloud Deployments}, year = 2023 }

  %0 Conference Paper %1 info3-article-2023-4 %A Nguyen, TrungKien %A Loh, Frank %A Nguyen, Tung %A Doan, Duong %A Huu Thanh, Nguyen %A Hoßfeld, Tobias %B IEEE International Conference on Communications 2023 - GreenNet Workshop %D 2023 %T Serverless Computing Lifecycle Model for Edge Cloud Deployments %X Serverless computing is a new cloud computing execution model. It offers little operational and administrative overhead, function activation on-demand, and significantly reduced resource consumption. For that reason, it is studied heavily in recent literature by means of handling incoming traffic, applicability for different tasks, and overall performance. Especially the introduction of states, where functionality is kept in CPU or memory can improve performance significantly. However, an in-depth analysis of the resource demand by among others, CPU and memory usage, latency, and energy consumption is still a blank spot in literature. To this end, we propose a serverless lifecycle model with intermediate states and deploy an image processing test setup in the edge cloud to test it. Furthermore, we measure important resource metrics of all states and state transitions of the model. This helps us to answer the question, whether keeping functions available in specific states of a serverless computing instance can improve performance without massive negative influence on the resource requirements.

• Data Usage in IoT: A Characterization of GTP Tunnels in M2M Mobile Networks Raffeck, Simon; Geißler, Stefan; Krolikowski, Michael; Gebert, Steffen; Hoßfeld, Tobias in 2nd IFIP/IEEE International workshop on Fully-Flexible Internet Architectures and Protocols for the Next-Generation Tactile Internet (FlexNGIA) (2022).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
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  IoT and M2M devices have seen a significant growth in usage and deployment over the last years. Gaining insight into device and data usage behavior exhibited by the participants of mobile networks is elementary for MNO and MVNO to scale their networks and provide a reliable service. This work aims to make use of its first of a kind dataset, spanning multiple countries and MNO, to provide a detailed characterization of GTP tunnels and devices. To this end, general statistics are used to describe the observed data traffic focusing on the distribution of the tunnel duration and volume as well as periodic device behavior. An approximate metric is introduced to analyze the periodicity and synchronicity of IoT devices. Lastly, we publish the data investigated in this work and provide a large scale dataset on the data usage behavior of IoT devices to interested researchers.

  @inproceedings{info3-inproceedings-2022-5, abstract = {IoT and M2M devices have seen a significant growth in usage and deployment over the last years. Gaining insight into device and data usage behavior exhibited by the participants of mobile networks is elementary for MNO and MVNO to scale their networks and provide a reliable service. This work aims to make use of its first of a kind dataset, spanning multiple countries and MNO, to provide a detailed characterization of GTP tunnels and devices. To this end, general statistics are used to describe the observed data traffic focusing on the distribution of the tunnel duration and volume as well as periodic device behavior. An approximate metric is introduced to analyze the periodicity and synchronicity of IoT devices. Lastly, we publish the data investigated in this work and provide a large scale dataset on the data usage behavior of IoT devices to interested researchers.}, author = {Raffeck, Simon and Geißler, Stefan and Krolikowski, Michael and Gebert, Steffen and Hoßfeld, Tobias}, booktitle = {2nd IFIP/IEEE International workshop on Fully-Flexible Internet Architectures and Protocols for the Next-Generation Tactile Internet (FlexNGIA)}, keywords = {can}, month = 4, title = {Data Usage in IoT: A Characterization of GTP Tunnels in M2M Mobile Networks}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-5 %A Raffeck, Simon %A Geißler, Stefan %A Krolikowski, Michael %A Gebert, Steffen %A Hoßfeld, Tobias %B 2nd IFIP/IEEE International workshop on Fully-Flexible Internet Architectures and Protocols for the Next-Generation Tactile Internet (FlexNGIA) %D 2022 %T Data Usage in IoT: A Characterization of GTP Tunnels in M2M Mobile Networks %X IoT and M2M devices have seen a significant growth in usage and deployment over the last years. Gaining insight into device and data usage behavior exhibited by the participants of mobile networks is elementary for MNO and MVNO to scale their networks and provide a reliable service. This work aims to make use of its first of a kind dataset, spanning multiple countries and MNO, to provide a detailed characterization of GTP tunnels and devices. To this end, general statistics are used to describe the observed data traffic focusing on the distribution of the tunnel duration and volume as well as periodic device behavior. An approximate metric is introduced to analyze the periodicity and synchronicity of IoT devices. Lastly, we publish the data investigated in this work and provide a large scale dataset on the data usage behavior of IoT devices to interested researchers.
• A Vital Improvement? Relating Google’s Core Web Vitals to Actual Web QoE Wehner, Nikolas; Amir, Monisha; Seufert, Michael; Schatz, Raimund; Hoßfeld, Tobias in 14th International Conference on Quality of Multimedia Experience (QoMEX), Best Paper Award (2022).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Providing sophisticated Web Quality of Experience (QoE) has become paramount for web service providers and network operators alike. Due to advances in Web technologies (HTML5, responsive design, etc.), traditional Web QoE models focusing mainly on loading times have to be refined and improved. In this work, we relate Google's Core Web Vitals, a set of metrics for improving user experience, to the loading time aspects of Web QoE. To this end, we first perform objective measurements in the Web using Google's Lighthouse. To close the gap between metrics and experience, we complement these objective measurements with subjective assessment by performing multiple crowdsourcing QoE studies. In these studies, we use CWeQS, a customized framework to emulate the entire web page loading process, and ask users for their experience while controlling the Core Web Vitals. Our results suggest that the Core Web Vitals have less predictive value for Web QoE than expected and that page loading times remain the main influence factor in this context.

  @inproceedings{info3-inproceedings-2022-12, abstract = {Providing sophisticated Web Quality of Experience (QoE) has become paramount for web service providers and network operators alike. Due to advances in Web technologies (HTML5, responsive design, etc.), traditional Web QoE models focusing mainly on loading times have to be refined and improved. In this work, we relate Google's Core Web Vitals, a set of metrics for improving user experience, to the loading time aspects of Web QoE. To this end, we first perform objective measurements in the Web using Google's Lighthouse. To close the gap between metrics and experience, we complement these objective measurements with subjective assessment by performing multiple crowdsourcing QoE studies. In these studies, we use CWeQS, a customized framework to emulate the entire web page loading process, and ask users for their experience while controlling the Core Web Vitals. Our results suggest that the Core Web Vitals have less predictive value for Web QoE than expected and that page loading times remain the main influence factor in this context.}, address = {Lippstadt, Germany}, author = {Wehner, Nikolas and Amir, Monisha and Seufert, Michael and Schatz, Raimund and Hoßfeld, Tobias}, booktitle = {14th International Conference on Quality of Multimedia Experience (QoMEX), Best Paper Award}, keywords = {ucn}, month = 9, title = {A Vital Improvement? Relating Google's Core Web Vitals to Actual Web QoE}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-12 %A Wehner, Nikolas %A Amir, Monisha %A Seufert, Michael %A Schatz, Raimund %A Hoßfeld, Tobias %B 14th International Conference on Quality of Multimedia Experience (QoMEX), Best Paper Award %C Lippstadt, Germany %D 2022 %T A Vital Improvement? Relating Google's Core Web Vitals to Actual Web QoE %X Providing sophisticated Web Quality of Experience (QoE) has become paramount for web service providers and network operators alike. Due to advances in Web technologies (HTML5, responsive design, etc.), traditional Web QoE models focusing mainly on loading times have to be refined and improved. In this work, we relate Google's Core Web Vitals, a set of metrics for improving user experience, to the loading time aspects of Web QoE. To this end, we first perform objective measurements in the Web using Google's Lighthouse. To close the gap between metrics and experience, we complement these objective measurements with subjective assessment by performing multiple crowdsourcing QoE studies. In these studies, we use CWeQS, a customized framework to emulate the entire web page loading process, and ask users for their experience while controlling the Core Web Vitals. Our results suggest that the Core Web Vitals have less predictive value for Web QoE than expected and that page loading times remain the main influence factor in this context.
• LoRaWAN Network Planning in Smart Environments: Towards Reliability, Scalability, and Cost Reduction Loh, Frank; Geißler, Stefan; Hoßfeld, Tobias in WueWoWAS 22 - KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks (2022).
  • [ Abstract ]
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  The goal in this work is to present a guidance for LoRaWAN planning to improve overall reliability for message transmissions and scalability. At the end, the cost component is discussed. Therefore, a five step approach is presented that helps to plan a LoRaWAN deployment step by step: Based on the device locations, an initial gateway placement is suggested followed by in-depth frequency and channel access planning. After an initial planning phase, updates for channel access and the initial gateway planning is suggested that should also be done periodically during network operation. Since current gateway placement approaches are only studied with random channel access, there is a lot of potential in the cell planning phase. Furthermore, the performance of different channel access approaches is highly related on network load, and thus cell size and sensor density. Last, the influence of different cell planning ideas on expected costs are discussed.

  @inproceedings{info3-inproceedings-2022-20, abstract = {The goal in this work is to present a guidance for LoRaWAN planning to improve overall reliability for message transmissions and scalability. At the end, the cost component is discussed. Therefore, a five step approach is presented that helps to plan a LoRaWAN deployment step by step: Based on the device locations, an initial gateway placement is suggested followed by in-depth frequency and channel access planning. After an initial planning phase, updates for channel access and the initial gateway planning is suggested that should also be done periodically during network operation. Since current gateway placement approaches are only studied with random channel access, there is a lot of potential in the cell planning phase. Furthermore, the performance of different channel access approaches is highly related on network load, and thus cell size and sensor density. Last, the influence of different cell planning ideas on expected costs are discussed.}, author = {Loh, Frank and Geißler, Stefan and Hoßfeld, Tobias}, booktitle = {WueWoWAS 22 - KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks}, keywords = {5mart}, month = 7, title = {LoRaWAN Network Planning in Smart Environments: Towards Reliability, Scalability, and Cost Reduction}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-20 %A Loh, Frank %A Geißler, Stefan %A Hoßfeld, Tobias %B WueWoWAS 22 - KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks %D 2022 %T LoRaWAN Network Planning in Smart Environments: Towards Reliability, Scalability, and Cost Reduction %X The goal in this work is to present a guidance for LoRaWAN planning to improve overall reliability for message transmissions and scalability. At the end, the cost component is discussed. Therefore, a five step approach is presented that helps to plan a LoRaWAN deployment step by step: Based on the device locations, an initial gateway placement is suggested followed by in-depth frequency and channel access planning. After an initial planning phase, updates for channel access and the initial gateway planning is suggested that should also be done periodically during network operation. Since current gateway placement approaches are only studied with random channel access, there is a lot of potential in the cell planning phase. Furthermore, the performance of different channel access approaches is highly related on network load, and thus cell size and sensor density. Last, the influence of different cell planning ideas on expected costs are discussed.
• Graph-Based Gateway Placement for Better Performance in LoRaWAN Deployments Loh, Frank; Mehling, Noah; Geißler, Stefan; Hoßfeld, Tobias in 20th Mediterranean Communication and Computer Networking Conference (MedComNet) (2022).
  • [ Abstract ]
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  Low Power Wide Area Networks with Long Range Wide Area Networks (LoRaWANs) as one of their most prominent representatives are very promising solutions for future Internet of Things deployments. The technology is characterized by low energy requirements leading to long battery lifetimes. However, the drawback is very limited throughput rates. However, the unreliable nature of the LoRa technology is hindering the adoption. Especially its random channel access approach leads to significant message collisions and thus, data loss in larger deployments. From a network planning point of view, one possibility to deal with collisions is the reduction of potentially colliding messages at the frequency bands in combination with limiting the transmission duration of messages. For that reason, we present a novel graph-based gateway placement approach. The main focus is collision probability reduction, which directly increases reliability in LoRaWAN deployments. We show that our approach performs similar to state-of-the-art related work in the worst case and reduces the required number of gateways by up to 40% while reducing the collision probability by up to 70%. Furthermore, we discuss the scalability of our approach to cover arbitrarily large networks with gateways and only little overhead by splitting the problem into smaller sub-problems.

  @inproceedings{info3-inproceedings-2022-19, abstract = {Low Power Wide Area Networks with Long Range Wide Area Networks (LoRaWANs) as one of their most prominent representatives are very promising solutions for future Internet of Things deployments. The technology is characterized by low energy requirements leading to long battery lifetimes. However, the drawback is very limited throughput rates. However, the unreliable nature of the LoRa technology is hindering the adoption. Especially its random channel access approach leads to significant message collisions and thus, data loss in larger deployments. From a network planning point of view, one possibility to deal with collisions is the reduction of potentially colliding messages at the frequency bands in combination with limiting the transmission duration of messages. For that reason, we present a novel graph-based gateway placement approach. The main focus is collision probability reduction, which directly increases reliability in LoRaWAN deployments. We show that our approach performs similar to state-of-the-art related work in the worst case and reduces the required number of gateways by up to 40% while reducing the collision probability by up to 70%. Furthermore, we discuss the scalability of our approach to cover arbitrarily large networks with gateways and only little overhead by splitting the problem into smaller sub-problems.}, author = {Loh, Frank and Mehling, Noah and Geißler, Stefan and Hoßfeld, Tobias}, booktitle = {20th Mediterranean Communication and Computer Networking Conference (MedComNet)}, keywords = {5mart}, month = 6, title = {Graph-Based Gateway Placement for Better Performance in LoRaWAN Deployments}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-19 %A Loh, Frank %A Mehling, Noah %A Geißler, Stefan %A Hoßfeld, Tobias %B 20th Mediterranean Communication and Computer Networking Conference (MedComNet) %D 2022 %T Graph-Based Gateway Placement for Better Performance in LoRaWAN Deployments %X Low Power Wide Area Networks with Long Range Wide Area Networks (LoRaWANs) as one of their most prominent representatives are very promising solutions for future Internet of Things deployments. The technology is characterized by low energy requirements leading to long battery lifetimes. However, the drawback is very limited throughput rates. However, the unreliable nature of the LoRa technology is hindering the adoption. Especially its random channel access approach leads to significant message collisions and thus, data loss in larger deployments. From a network planning point of view, one possibility to deal with collisions is the reduction of potentially colliding messages at the frequency bands in combination with limiting the transmission duration of messages. For that reason, we present a novel graph-based gateway placement approach. The main focus is collision probability reduction, which directly increases reliability in LoRaWAN deployments. We show that our approach performs similar to state-of-the-art related work in the worst case and reduces the required number of gateways by up to 40% while reducing the collision probability by up to 70%. Furthermore, we discuss the scalability of our approach to cover arbitrarily large networks with gateways and only little overhead by splitting the problem into smaller sub-problems.
• Fingerprinting Webpages and Smartphone Apps from Encrypted Network Traffic with WebScanner Casas, Pedro; Wehner, Nikolas; Wassermann, Sarah; Seufert, Michael in Global Internet (GI) Symposium (2022).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  The wide adoption of end-to-end encryption drastically limits the visibility Internet Service Providers (ISPs) have on the services consumed by their customers. This is particularly challenging for monitoring and analysis of web and apps traffic, which is highly complex and heterogeneous. Loading a web page or app today requires tens of flows to download the various resources located in distributed cloud servers from different content providers. We introduce WebScanner, a webpage and app fingerprinting approach capable to identify all the traffic flows corresponding to individual webpage and app loading sessions within concurrent web pages traffic, enabling highly detailed, per webpage analysis in practical deployments. Different from the state of the art in web and app traffic fingerprinting, and as our most relevant contribution, WebScanner automatically performs the parsing of all the traffic generated by a web visit and its isolation from concurrent traffic, instead of assuming that an external oracle system does so. WebScanner also implements a deep fingerprinting approach to detect user action-dependent traffic from apps, relying on simple machine learning models and strong input features as fingerprints. Extensive evaluation across a large measurement dataset of popular webpages and mobile apps confirms the outstanding performance of WebScanner, identifying the top-500 Alexa websites with precision and recall (P/R) above 95%, isolating their full contents with P/R above 80% for up to 15 concurrent webpages, and detecting specific action-dependent apps traffic with average P/R above 92%.

  @inproceedings{info3-inproceedings-2022-18, abstract = {The wide adoption of end-to-end encryption drastically limits the visibility Internet Service Providers (ISPs) have on the services consumed by their customers. This is particularly challenging for monitoring and analysis of web and apps traffic, which is highly complex and heterogeneous. Loading a web page or app today requires tens of flows to download the various resources located in distributed cloud servers from different content providers. We introduce WebScanner, a webpage and app fingerprinting approach capable to identify all the traffic flows corresponding to individual webpage and app loading sessions within concurrent web pages traffic, enabling highly detailed, per webpage analysis in practical deployments. Different from the state of the art in web and app traffic fingerprinting, and as our most relevant contribution, WebScanner automatically performs the parsing of all the traffic generated by a web visit and its isolation from concurrent traffic, instead of assuming that an external oracle system does so. WebScanner also implements a deep fingerprinting approach to detect user action-dependent traffic from apps, relying on simple machine learning models and strong input features as fingerprints. Extensive evaluation across a large measurement dataset of popular webpages and mobile apps confirms the outstanding performance of WebScanner, identifying the top-500 Alexa websites with precision and recall (P/R) above 95%, isolating their full contents with P/R above 80% for up to 15 concurrent webpages, and detecting specific action-dependent apps traffic with average P/R above 92%.}, address = {Paris, France}, author = {Casas, Pedro and Wehner, Nikolas and Wassermann, Sarah and Seufert, Michael}, booktitle = {Global Internet (GI) Symposium}, keywords = {ucn}, month = 11, title = {Fingerprinting Webpages and Smartphone Apps from Encrypted Network Traffic with WebScanner}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-18 %A Casas, Pedro %A Wehner, Nikolas %A Wassermann, Sarah %A Seufert, Michael %B Global Internet (GI) Symposium %C Paris, France %D 2022 %T Fingerprinting Webpages and Smartphone Apps from Encrypted Network Traffic with WebScanner %X The wide adoption of end-to-end encryption drastically limits the visibility Internet Service Providers (ISPs) have on the services consumed by their customers. This is particularly challenging for monitoring and analysis of web and apps traffic, which is highly complex and heterogeneous. Loading a web page or app today requires tens of flows to download the various resources located in distributed cloud servers from different content providers. We introduce WebScanner, a webpage and app fingerprinting approach capable to identify all the traffic flows corresponding to individual webpage and app loading sessions within concurrent web pages traffic, enabling highly detailed, per webpage analysis in practical deployments. Different from the state of the art in web and app traffic fingerprinting, and as our most relevant contribution, WebScanner automatically performs the parsing of all the traffic generated by a web visit and its isolation from concurrent traffic, instead of assuming that an external oracle system does so. WebScanner also implements a deep fingerprinting approach to detect user action-dependent traffic from apps, relying on simple machine learning models and strong input features as fingerprints. Extensive evaluation across a large measurement dataset of popular webpages and mobile apps confirms the outstanding performance of WebScanner, identifying the top-500 Alexa websites with precision and recall (P/R) above 95%, isolating their full contents with P/R above 80% for up to 15 concurrent webpages, and detecting specific action-dependent apps traffic with average P/R above 92%.
• Discrete-Time Analysis of Multi-Component Queuing Networks under Renewal Approximation Geißler, Stefan; Lange, Stanislav; Haßllinger, Gerhard; Tran-Gia, Phuoc; Hoßfeld, Tobias in 34st International Teletraffic Congress (ITC). , Shenzhen, China (2022).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  The analytical and numerical performance evaluation of network components and distributed systems has been a staple in the networking community for many years. However, the ever growing complexity of modern systems and the need to gain detailed insights into systems consisting of many, interconnected components emphasizes the need for an extension to the classical single-component approach, and although approaches like Jackson Networks exist, their limited application scope lags behind the complexity of modern environments. To this end, we revisit existing models of the common Gi/Gi/1-oo queue, extend them to allow the concatenation of multiple queueing components, and evaluate the approximation error introduced through renewal approximation. We revisit previously performed parameter studies and evaluate the approximation error for a wide range of parameter combinations that we can solve through the power of modern computing equipment and efficient numerical implementations of our models. We show the main impact factors for the linear concatenation of queueing components as well as the split and superposition of processes. Our evaluations show that the renewal approximation can be applied to a wide range of parameters while still obtaining results within acceptable error margins.

  @inproceedings{info3-inproceedings-2022-17, abstract = {The analytical and numerical performance evaluation of network components and distributed systems has been a staple in the networking community for many years. However, the ever growing complexity of modern systems and the need to gain detailed insights into systems consisting of many, interconnected components emphasizes the need for an extension to the classical single-component approach, and although approaches like Jackson Networks exist, their limited application scope lags behind the complexity of modern environments. To this end, we revisit existing models of the common Gi/Gi/1-oo queue, extend them to allow the concatenation of multiple queueing components, and evaluate the approximation error introduced through renewal approximation. We revisit previously performed parameter studies and evaluate the approximation error for a wide range of parameter combinations that we can solve through the power of modern computing equipment and efficient numerical implementations of our models. We show the main impact factors for the linear concatenation of queueing components as well as the split and superposition of processes. Our evaluations show that the renewal approximation can be applied to a wide range of parameters while still obtaining results within acceptable error margins.}, author = {Geißler, Stefan and Lange, Stanislav and Haßllinger, Gerhard and Tran-Gia, Phuoc and Hoßfeld, Tobias}, booktitle = {34st International Teletraffic Congress (ITC). , Shenzhen, China}, keywords = {can}, month = 9, title = {Discrete-Time Analysis of Multi-Component Queuing Networks under Renewal Approximation}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-17 %A Geißler, Stefan %A Lange, Stanislav %A Haßllinger, Gerhard %A Tran-Gia, Phuoc %A Hoßfeld, Tobias %B 34st International Teletraffic Congress (ITC). , Shenzhen, China %D 2022 %T Discrete-Time Analysis of Multi-Component Queuing Networks under Renewal Approximation %X The analytical and numerical performance evaluation of network components and distributed systems has been a staple in the networking community for many years. However, the ever growing complexity of modern systems and the need to gain detailed insights into systems consisting of many, interconnected components emphasizes the need for an extension to the classical single-component approach, and although approaches like Jackson Networks exist, their limited application scope lags behind the complexity of modern environments. To this end, we revisit existing models of the common Gi/Gi/1-oo queue, extend them to allow the concatenation of multiple queueing components, and evaluate the approximation error introduced through renewal approximation. We revisit previously performed parameter studies and evaluate the approximation error for a wide range of parameter combinations that we can solve through the power of modern computing equipment and efficient numerical implementations of our models. We show the main impact factors for the linear concatenation of queueing components as well as the split and superposition of processes. Our evaluations show that the renewal approximation can be applied to a wide range of parameters while still obtaining results within acceptable error margins.
• Comparing Traditional and GAN-based Approaches for the Synthesis of Wide Area Network Topologies Dietz, Katharina; Seufert, Michael; Hoßfeld, Tobias in 18th International Conference on Network and Service Management (CNSM) (2022).
  • [ BibTeX ]
  • [ EndNote ]
  @inproceedings{info3-inproceedings-2022-16, address = {Thessaloniki, Greece}, author = {Dietz, Katharina and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {18th International Conference on Network and Service Management (CNSM)}, keywords = {ucn}, month = 10, title = {Comparing Traditional and GAN-based Approaches for the Synthesis of Wide Area Network Topologies}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-16 %A Dietz, Katharina %A Seufert, Michael %A Hoßfeld, Tobias %B 18th International Conference on Network and Service Management (CNSM) %C Thessaloniki, Greece %D 2022 %T Comparing Traditional and GAN-based Approaches for the Synthesis of Wide Area Network Topologies
• Constant Delay Switching: Asynchronous Traffic Shaping with Jitter Control Grigorjew, Alexej; Metzger, Florian; Hoßfeld, Tobias; Specht, Johannes; Götz, Franz-Josef; Chen, Feng; Schmitt, Jürgen in 2022 IFIP Networking Conference (IFIP Networking) (2022).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Recent developments in the Time Sensitive Networking (TSN) group have put forth a number of mechanisms to improve deterministic latency in layer 2 switches. Their shaping approaches differ with respect to prerequisites, flexibility, maximum latency, and latency variation (jitter). Asynchronous solutions provide flexibility in dynamic scenarios, but Credit-Based Shaping (CBS) and Asynchronous Traffic Shaping (ATS) come with a high latency variance, as the minimum latency is not affected by them. Some applications in industrial and automotive use cases require low jitter while trying to avoid a dependency on time synchronization, and even TSN's redundancy mechanism benefits from a lower latency variance. This work is bridging the gap between low-jitter transmission requirements and asynchronous shaping mechanisms. In this paper, the application of a stateless Asynchronous Constant Delay Shaper (ACDS) is discussed. It collects the queuing duration from the previous bridge to delay each frame for the remaining time such that a constant per-hop delay for each frame is achieved. The discussion includes the prerequisites, the mechanism itself, and its technical complexity, as well as a formal analysis of its guaranteed latency by proving its relation to a token-bucket based ATS. Further, two extensions are discussed, and an evaluation shows the applicability of ACDS by comparing its jitter to ATS in a frame-level simulation.

  @inproceedings{info3-inproceedings-2022-15, abstract = {Recent developments in the Time Sensitive Networking (TSN) group have put forth a number of mechanisms to improve deterministic latency in layer 2 switches. Their shaping approaches differ with respect to prerequisites, flexibility, maximum latency, and latency variation (jitter). Asynchronous solutions provide flexibility in dynamic scenarios, but Credit-Based Shaping (CBS) and Asynchronous Traffic Shaping (ATS) come with a high latency variance, as the minimum latency is not affected by them. Some applications in industrial and automotive use cases require low jitter while trying to avoid a dependency on time synchronization, and even TSN's redundancy mechanism benefits from a lower latency variance. This work is bridging the gap between low-jitter transmission requirements and asynchronous shaping mechanisms. In this paper, the application of a stateless Asynchronous Constant Delay Shaper (ACDS) is discussed. It collects the queuing duration from the previous bridge to delay each frame for the remaining time such that a constant per-hop delay for each frame is achieved. The discussion includes the prerequisites, the mechanism itself, and its technical complexity, as well as a formal analysis of its guaranteed latency by proving its relation to a token-bucket based ATS. Further, two extensions are discussed, and an evaluation shows the applicability of ACDS by comparing its jitter to ATS in a frame-level simulation.}, author = {Grigorjew, Alexej and Metzger, Florian and Hoßfeld, Tobias and Specht, Johannes and Götz, Franz-Josef and Chen, Feng and Schmitt, Jürgen}, booktitle = {2022 IFIP Networking Conference (IFIP Networking)}, keywords = {kosinu5}, month = 6, title = {Constant Delay Switching: Asynchronous Traffic Shaping with Jitter Control}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-15 %A Grigorjew, Alexej %A Metzger, Florian %A Hoßfeld, Tobias %A Specht, Johannes %A Götz, Franz-Josef %A Chen, Feng %A Schmitt, Jürgen %B 2022 IFIP Networking Conference (IFIP Networking) %D 2022 %T Constant Delay Switching: Asynchronous Traffic Shaping with Jitter Control %X Recent developments in the Time Sensitive Networking (TSN) group have put forth a number of mechanisms to improve deterministic latency in layer 2 switches. Their shaping approaches differ with respect to prerequisites, flexibility, maximum latency, and latency variation (jitter). Asynchronous solutions provide flexibility in dynamic scenarios, but Credit-Based Shaping (CBS) and Asynchronous Traffic Shaping (ATS) come with a high latency variance, as the minimum latency is not affected by them. Some applications in industrial and automotive use cases require low jitter while trying to avoid a dependency on time synchronization, and even TSN's redundancy mechanism benefits from a lower latency variance. This work is bridging the gap between low-jitter transmission requirements and asynchronous shaping mechanisms. In this paper, the application of a stateless Asynchronous Constant Delay Shaper (ACDS) is discussed. It collects the queuing duration from the previous bridge to delay each frame for the remaining time such that a constant per-hop delay for each frame is achieved. The discussion includes the prerequisites, the mechanism itself, and its technical complexity, as well as a formal analysis of its guaranteed latency by proving its relation to a token-bucket based ATS. Further, two extensions are discussed, and an evaluation shows the applicability of ACDS by comparing its jitter to ATS in a frame-level simulation.
• Affordable Measurement Setups for Networking Device Latency with Sub-Microsecond Accuracy Grigorjew, Alexej; Diederich, Philip; Hoßfeld, Tobias; Kellerer, Wolfgang in WueWoWAS’22 KuVS Fachgespraech - Wuerzburg Workshop on Next-Generation Communication Networks (2022).
  • [ Abstract ]
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  This document presents a networking latency measurement setup that focuses on affordability and universal applicability, and can provide sub-microsecond accuracy. It explains the prerequisites, hardware choices, and considerations to respect during measurement. In addition, it discusses the necessity for exhaustive latency measurements when dealing with high availability and low latency requirements. Preliminary results show that the accuracy is within 0.02 microseconds when used with the Intel I350-T2 network adapter.

  @inproceedings{info3-inproceedings-2022-14, abstract = {This document presents a networking latency measurement setup that focuses on affordability and universal applicability, and can provide sub-microsecond accuracy. It explains the prerequisites, hardware choices, and considerations to respect during measurement. In addition, it discusses the necessity for exhaustive latency measurements when dealing with high availability and low latency requirements. Preliminary results show that the accuracy is within 0.02 microseconds when used with the Intel I350-T2 network adapter.}, author = {Grigorjew, Alexej and Diederich, Philip and Hoßfeld, Tobias and Kellerer, Wolfgang}, booktitle = {WueWoWAS'22 KuVS Fachgespraech - Wuerzburg Workshop on Next-Generation Communication Networks}, keywords = {appaware2}, month = 7, title = {Affordable Measurement Setups for Networking Device Latency with Sub-Microsecond Accuracy}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-14 %A Grigorjew, Alexej %A Diederich, Philip %A Hoßfeld, Tobias %A Kellerer, Wolfgang %B WueWoWAS'22 KuVS Fachgespraech - Wuerzburg Workshop on Next-Generation Communication Networks %D 2022 %T Affordable Measurement Setups for Networking Device Latency with Sub-Microsecond Accuracy %X This document presents a networking latency measurement setup that focuses on affordability and universal applicability, and can provide sub-microsecond accuracy. It explains the prerequisites, hardware choices, and considerations to respect during measurement. In addition, it discusses the necessity for exhaustive latency measurements when dealing with high availability and low latency requirements. Preliminary results show that the accuracy is within 0.02 microseconds when used with the Intel I350-T2 network adapter.
• Waiting along the Path: How Browsing Delays Impact the QoE of Music Streaming Applications Seufert, Anika; Schweifler, Ralf; Poignée, Fabian; Seufert, Michael; Hoßfeld, Tobias in 14th International Conference on Quality of Multimedia Experience (QoMEX) (2022).
  • [ Abstract ]
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  Streaming has become the dominant source of media consumption, which not only applies to the widely researched field of video streaming, but also to music streaming. Here, previous studies so far have only researched the impact of streaming aspects, such as stalling events or initial loading times, on the QoE of music streaming. However, when using a music streaming application, users are already facing waiting times along the click path before they can start the actual streaming. These waiting times are caused by browsing delays, e.g., during searching for songs or scrolling through playlists, and can potentially deteriorate the QoE of the music streaming application. In this work, we conduct an online QoE study to quantify the impact of these browsing delays with the support of an emulated mobile music streaming web app. We found that browsing delays have no impact on the music streaming QoE, which shows that users are able to clearly distinguish between the two main functionalities of such apps, namely, browsing and streaming. However, browsing delays significantly reduce the QoE of the entire music streaming application, to a similar extent as if QoE degradations happen during the actual streaming. This shows that both browsing and streaming are equally important and have to be considered when designing music streaming applications.

  @inproceedings{info3-inproceedings-2022-13, abstract = {Streaming has become the dominant source of media consumption, which not only applies to the widely researched field of video streaming, but also to music streaming. Here, previous studies so far have only researched the impact of streaming aspects, such as stalling events or initial loading times, on the QoE of music streaming. However, when using a music streaming application, users are already facing waiting times along the click path before they can start the actual streaming. These waiting times are caused by browsing delays, e.g., during searching for songs or scrolling through playlists, and can potentially deteriorate the QoE of the music streaming application. In this work, we conduct an online QoE study to quantify the impact of these browsing delays with the support of an emulated mobile music streaming web app. We found that browsing delays have no impact on the music streaming QoE, which shows that users are able to clearly distinguish between the two main functionalities of such apps, namely, browsing and streaming. However, browsing delays significantly reduce the QoE of the entire music streaming application, to a similar extent as if QoE degradations happen during the actual streaming. This shows that both browsing and streaming are equally important and have to be considered when designing music streaming applications.}, author = {Seufert, Anika and Schweifler, Ralf and Poignée, Fabian and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {14th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {sys:hidden:inproceedings}, month = 9, title = {Waiting along the Path: How Browsing Delays Impact the QoE of Music Streaming Applications}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-13 %A Seufert, Anika %A Schweifler, Ralf %A Poignée, Fabian %A Seufert, Michael %A Hoßfeld, Tobias %B 14th International Conference on Quality of Multimedia Experience (QoMEX) %D 2022 %T Waiting along the Path: How Browsing Delays Impact the QoE of Music Streaming Applications %X Streaming has become the dominant source of media consumption, which not only applies to the widely researched field of video streaming, but also to music streaming. Here, previous studies so far have only researched the impact of streaming aspects, such as stalling events or initial loading times, on the QoE of music streaming. However, when using a music streaming application, users are already facing waiting times along the click path before they can start the actual streaming. These waiting times are caused by browsing delays, e.g., during searching for songs or scrolling through playlists, and can potentially deteriorate the QoE of the music streaming application. In this work, we conduct an online QoE study to quantify the impact of these browsing delays with the support of an emulated mobile music streaming web app. We found that browsing delays have no impact on the music streaming QoE, which shows that users are able to clearly distinguish between the two main functionalities of such apps, namely, browsing and streaming. However, browsing delays significantly reduce the QoE of the entire music streaming application, to a similar extent as if QoE degradations happen during the actual streaming. This shows that both browsing and streaming are equally important and have to be considered when designing music streaming applications.
• Not all Web Pages are Born the Same. Content Tailored Learning for Web QoE Inference Casas, Pedro; Wassermann, Sarah; Wehner, Nikolas; Seufert, Michael; Hoßfeld, Tobias in IEEE International Symposium on Measurements & Networking (M&N 2022) (2022).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Web Quality of Experience (QoE) monitoring is a critical task for Internet Service Providers (ISPs), especially due to the key role played by customer experience in churn management. Previously, we have tackled the problem of Web QoE inference from the ISP perspective, relying on passive measurement of encrypted network traffic and machine learning models. In this paper, we exploit the broad heterogeneity of contents embedded in web pages to improve the state of the art performance in Web QoE inference, relying on web-content learning model tailoring. By analyzing the top-500 most popular web pages of the Internet through unsupervised learning, we discover different web page content classes which realize significantly different Web QoE inference performance. We train supervised learning inference models separately for each of these classes, using the well-known Speed Index (SI) metric as proxy to Web QoE. Empirical evaluations on a large corpus of Web QoE measurements for top popular websites demonstrate that our combined content-tailored approach improves the inference performance of the SI by almost 30% with respect to previous single-model approaches, reducing the QoE inference error in terms of mean opinion scores by more than 40%.

  @inproceedings{info3-inproceedings-2022-10, abstract = {Web Quality of Experience (QoE) monitoring is a critical task for Internet Service Providers (ISPs), especially due to the key role played by customer experience in churn management. Previously, we have tackled the problem of Web QoE inference from the ISP perspective, relying on passive measurement of encrypted network traffic and machine learning models. In this paper, we exploit the broad heterogeneity of contents embedded in web pages to improve the state of the art performance in Web QoE inference, relying on web-content learning model tailoring. By analyzing the top-500 most popular web pages of the Internet through unsupervised learning, we discover different web page content classes which realize significantly different Web QoE inference performance. We train supervised learning inference models separately for each of these classes, using the well-known Speed Index (SI) metric as proxy to Web QoE. Empirical evaluations on a large corpus of Web QoE measurements for top popular websites demonstrate that our combined content-tailored approach improves the inference performance of the SI by almost 30% with respect to previous single-model approaches, reducing the QoE inference error in terms of mean opinion scores by more than 40%.}, author = {Casas, Pedro and Wassermann, Sarah and Wehner, Nikolas and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {IEEE International Symposium on Measurements & Networking (M&N 2022)}, keywords = {sys:hidden:inproceedings}, month = 7, title = {Not all Web Pages are Born the Same. Content Tailored Learning for Web QoE Inference}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-10 %A Casas, Pedro %A Wassermann, Sarah %A Wehner, Nikolas %A Seufert, Michael %A Hoßfeld, Tobias %B IEEE International Symposium on Measurements & Networking (M&N 2022) %D 2022 %T Not all Web Pages are Born the Same. Content Tailored Learning for Web QoE Inference %X Web Quality of Experience (QoE) monitoring is a critical task for Internet Service Providers (ISPs), especially due to the key role played by customer experience in churn management. Previously, we have tackled the problem of Web QoE inference from the ISP perspective, relying on passive measurement of encrypted network traffic and machine learning models. In this paper, we exploit the broad heterogeneity of contents embedded in web pages to improve the state of the art performance in Web QoE inference, relying on web-content learning model tailoring. By analyzing the top-500 most popular web pages of the Internet through unsupervised learning, we discover different web page content classes which realize significantly different Web QoE inference performance. We train supervised learning inference models separately for each of these classes, using the well-known Speed Index (SI) metric as proxy to Web QoE. Empirical evaluations on a large corpus of Web QoE measurements for top popular websites demonstrate that our combined content-tailored approach improves the inference performance of the SI by almost 30% with respect to previous single-model approaches, reducing the QoE inference error in terms of mean opinion scores by more than 40%.
• Identification of Signaling Patterns in Mobile IoT Signaling Traffic Vomhoff, Viktoria; Geißler, Stefan; Hoßfeld, Tobias in WueWoWAS 22 - KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks (2022).
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  @inproceedings{info3-inproceedings-2022-8, author = {Vomhoff, Viktoria and Geißler, Stefan and Hoßfeld, Tobias}, booktitle = {WueWoWAS 22 - KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks}, keywords = {can}, month = 7, title = {Identification of Signaling Patterns in Mobile IoT Signaling Traffic}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-8 %A Vomhoff, Viktoria %A Geißler, Stefan %A Hoßfeld, Tobias %B WueWoWAS 22 - KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks %D 2022 %T Identification of Signaling Patterns in Mobile IoT Signaling Traffic
• DeepCrypt - Deep Learning for QoE Monitoring and Fingerprinting of User Actions in Adaptive Video Streaming Casas, Pedro; Seufert, Michael; Wassermann, Sarah; Gardlo, Bruno; Wehner, Nikolas; Schatz, Raimund in IEEE Conference on Network Softwarization (IEEE NetSoft 2022) (2022).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  We introduce DeepCrypt, a deep-learning based approach to analyze YouTube video streaming Quality of Experience (QoE) from the Internet Service Provider (ISP) perspective, relying exclusively on the analysis of encrypted network traffic. Using raw features derived on-line from the encrypted stream of bytes, DeepCrypt can infer six different video QoE indicators capturing the user-perceived performance of the service, including the initial playback delay, the number and frequency of rebuffering events, the video playback quality, the video encoding bitrate, and the number of quality changes. DeepCrypt offers deep visibility into the behavior of the end-user, enabling the fingerprinting and detection of different user actions on the video player, such as video pauses and playback scrubbing (forward, backward, out-of-buffer), offering a complete visibility on the video streaming process from in-network traffic measurements. Extensive evaluations over a large and heterogeneous dataset composed of mobile and fixed-line measurements, using the YouTube HTML5 player, the native YouTube mobile app, as well as a generic HTML5 video player built on top of open source libraries, and considering measurements collected at different ISPs, confirm the out-performance of DeepCrypt over previously used shallow-learning models, as well as the deep-model generalization to different video players and network setups. To the best of our knowledge, this is the first paper tackling such a combined QoE and user-actions approach for video streaming applications, using deep learning models over heterogeneous measurements.

  @inproceedings{info3-inproceedings-2022-9, abstract = {We introduce DeepCrypt, a deep-learning based approach to analyze YouTube video streaming Quality of Experience (QoE) from the Internet Service Provider (ISP) perspective, relying exclusively on the analysis of encrypted network traffic. Using raw features derived on-line from the encrypted stream of bytes, DeepCrypt can infer six different video QoE indicators capturing the user-perceived performance of the service, including the initial playback delay, the number and frequency of rebuffering events, the video playback quality, the video encoding bitrate, and the number of quality changes. DeepCrypt offers deep visibility into the behavior of the end-user, enabling the fingerprinting and detection of different user actions on the video player, such as video pauses and playback scrubbing (forward, backward, out-of-buffer), offering a complete visibility on the video streaming process from in-network traffic measurements. Extensive evaluations over a large and heterogeneous dataset composed of mobile and fixed-line measurements, using the YouTube HTML5 player, the native YouTube mobile app, as well as a generic HTML5 video player built on top of open source libraries, and considering measurements collected at different ISPs, confirm the out-performance of DeepCrypt over previously used shallow-learning models, as well as the deep-model generalization to different video players and network setups. To the best of our knowledge, this is the first paper tackling such a combined QoE and user-actions approach for video streaming applications, using deep learning models over heterogeneous measurements.}, author = {Casas, Pedro and Seufert, Michael and Wassermann, Sarah and Gardlo, Bruno and Wehner, Nikolas and Schatz, Raimund}, booktitle = {IEEE Conference on Network Softwarization (IEEE NetSoft 2022)}, keywords = {sys:hidden:inproceedings}, month = 6, title = {DeepCrypt - Deep Learning for QoE Monitoring and Fingerprinting of User Actions in Adaptive Video Streaming}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-9 %A Casas, Pedro %A Seufert, Michael %A Wassermann, Sarah %A Gardlo, Bruno %A Wehner, Nikolas %A Schatz, Raimund %B IEEE Conference on Network Softwarization (IEEE NetSoft 2022) %D 2022 %T DeepCrypt - Deep Learning for QoE Monitoring and Fingerprinting of User Actions in Adaptive Video Streaming %X We introduce DeepCrypt, a deep-learning based approach to analyze YouTube video streaming Quality of Experience (QoE) from the Internet Service Provider (ISP) perspective, relying exclusively on the analysis of encrypted network traffic. Using raw features derived on-line from the encrypted stream of bytes, DeepCrypt can infer six different video QoE indicators capturing the user-perceived performance of the service, including the initial playback delay, the number and frequency of rebuffering events, the video playback quality, the video encoding bitrate, and the number of quality changes. DeepCrypt offers deep visibility into the behavior of the end-user, enabling the fingerprinting and detection of different user actions on the video player, such as video pauses and playback scrubbing (forward, backward, out-of-buffer), offering a complete visibility on the video streaming process from in-network traffic measurements. Extensive evaluations over a large and heterogeneous dataset composed of mobile and fixed-line measurements, using the YouTube HTML5 player, the native YouTube mobile app, as well as a generic HTML5 video player built on top of open source libraries, and considering measurements collected at different ISPs, confirm the out-performance of DeepCrypt over previously used shallow-learning models, as well as the deep-model generalization to different video players and network setups. To the best of our knowledge, this is the first paper tackling such a combined QoE and user-actions approach for video streaming applications, using deep learning models over heterogeneous measurements.
• On Learning Hierarchical Embeddings from Encrypted Network Traffic Wehner, Nikolas; Ring, Markus; Schüler, Joshua; Hotho, Andreas; Hoßfeld, Tobias; Seufert, Michael in 33th IEEE/IFIP Network Operations and Management Symposium (NOMS) (2022).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  This work presents a novel concept for learning embeddings from encrypted network traffic. In contrast to existing approaches, we evaluate the feasibility of hierarchical embeddings by iteratively aggregating packet embeddings to flow embeddings, and flow embeddings to trace embeddings. The hierarchical embedding concept was designed to especially consider complex dependencies of Internet traffic on different time scales. We describe this novel embedding concept for the domain of network traffic in full detail, and evaluate its performance for the downstream task of website fingerprinting, i.e., identifying websites from encrypted traffic, which is relevant for network management, e.g., as a prerequisite for QoE monitoring or for intrusion detection. Our evaluation reveals that embeddings are a promising solution for website fingerprinting as our model correctly labels up to 99.8\% of traces from 500 target websites.

  @inproceedings{info3-inproceedings-2022-1, abstract = {This work presents a novel concept for learning embeddings from encrypted network traffic. In contrast to existing approaches, we evaluate the feasibility of hierarchical embeddings by iteratively aggregating packet embeddings to flow embeddings, and flow embeddings to trace embeddings. The hierarchical embedding concept was designed to especially consider complex dependencies of Internet traffic on different time scales. We describe this novel embedding concept for the domain of network traffic in full detail, and evaluate its performance for the downstream task of website fingerprinting, i.e., identifying websites from encrypted traffic, which is relevant for network management, e.g., as a prerequisite for QoE monitoring or for intrusion detection. Our evaluation reveals that embeddings are a promising solution for website fingerprinting as our model correctly labels up to 99.8\% of traces from 500 target websites.}, address = {Budapest, Hungary}, author = {Wehner, Nikolas and Ring, Markus and Schüler, Joshua and Hotho, Andreas and Hoßfeld, Tobias and Seufert, Michael}, booktitle = {33th IEEE/IFIP Network Operations and Management Symposium (NOMS)}, keywords = {sys:hidden:inproceedings}, month = 4, title = {On Learning Hierarchical Embeddings from Encrypted Network Traffic}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-1 %A Wehner, Nikolas %A Ring, Markus %A Schüler, Joshua %A Hotho, Andreas %A Hoßfeld, Tobias %A Seufert, Michael %B 33th IEEE/IFIP Network Operations and Management Symposium (NOMS) %C Budapest, Hungary %D 2022 %T On Learning Hierarchical Embeddings from Encrypted Network Traffic %X This work presents a novel concept for learning embeddings from encrypted network traffic. In contrast to existing approaches, we evaluate the feasibility of hierarchical embeddings by iteratively aggregating packet embeddings to flow embeddings, and flow embeddings to trace embeddings. The hierarchical embedding concept was designed to especially consider complex dependencies of Internet traffic on different time scales. We describe this novel embedding concept for the domain of network traffic in full detail, and evaluate its performance for the downstream task of website fingerprinting, i.e., identifying websites from encrypted traffic, which is relevant for network management, e.g., as a prerequisite for QoE monitoring or for intrusion detection. Our evaluation reveals that embeddings are a promising solution for website fingerprinting as our model correctly labels up to 99.8\% of traces from 500 target websites.
• X-Ray Goggles for the ISP: Improving in-Network Web and App QoE Monitoring with Deep Learning Casas, Pedro; Wassermann, Sarah; Seufert, Michael; Wehner, Nikolas; Dinica, Olivia; Hoßfeld, Tobias in Network Traffic Measurement and Analysis Conference (TMA) (2022).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  The wide adoption of end-to-end encryption is drastically limiting the visibility Internet Service Providers (ISPs) have on the performance of the services consumed by their customers. In times of strong competition, where customer experience plays a key role in churn management, ISPs require novel solutions enabling network-wide Quality of Experience (QoE) monitoring. To this end, we present DeepQoE, a deep-learning based approach to infer the QoE of web services and mobile applications from the ISP perspective, relying exclusively on the analysis of encrypted network traffic. Using raw features derived from the encrypted stream of bytes as input to deep Convolutional Neural Networks (CNNs), DeepQoE infers the Speed Index of web browsing sessions and general mobile apps with unprecedented accuracy, improving the state of the art by more than 25%, and reducing the QoE inference error in terms of mean opinion scores by nearly 40%. DeepQoE implements a web fingerprinting solution to identify individual web browsing sessions within concurrent web pages traffic, enabling highly detailed, per web page QoE inference in practical deployments. Extensive evaluations over a large and heterogeneous dataset composed of web and app measurements, using different device types and for top-popular websites and apps, confirm the out-performance of DeepQoE over previously used shallow-learning models, as well as the deep-model generalization to different devices, web pages, apps, and network setups. DeepQoE is the first deployable system providing such a deep, highly-detailed QoE for individual web browsing and mobile apps over encrypted traffic, using deep learning models on heterogeneous measurements.

  @inproceedings{info3-inproceedings-2022-11, abstract = {The wide adoption of end-to-end encryption is drastically limiting the visibility Internet Service Providers (ISPs) have on the performance of the services consumed by their customers. In times of strong competition, where customer experience plays a key role in churn management, ISPs require novel solutions enabling network-wide Quality of Experience (QoE) monitoring. To this end, we present DeepQoE, a deep-learning based approach to infer the QoE of web services and mobile applications from the ISP perspective, relying exclusively on the analysis of encrypted network traffic. Using raw features derived from the encrypted stream of bytes as input to deep Convolutional Neural Networks (CNNs), DeepQoE infers the Speed Index of web browsing sessions and general mobile apps with unprecedented accuracy, improving the state of the art by more than 25%, and reducing the QoE inference error in terms of mean opinion scores by nearly 40%. DeepQoE implements a web fingerprinting solution to identify individual web browsing sessions within concurrent web pages traffic, enabling highly detailed, per web page QoE inference in practical deployments. Extensive evaluations over a large and heterogeneous dataset composed of web and app measurements, using different device types and for top-popular websites and apps, confirm the out-performance of DeepQoE over previously used shallow-learning models, as well as the deep-model generalization to different devices, web pages, apps, and network setups. DeepQoE is the first deployable system providing such a deep, highly-detailed QoE for individual web browsing and mobile apps over encrypted traffic, using deep learning models on heterogeneous measurements.}, author = {Casas, Pedro and Wassermann, Sarah and Seufert, Michael and Wehner, Nikolas and Dinica, Olivia and Hoßfeld, Tobias}, booktitle = {Network Traffic Measurement and Analysis Conference (TMA)}, keywords = {sys:hidden:inproceedings}, month = 6, title = {X-Ray Goggles for the ISP: Improving in-Network Web and App QoE Monitoring with Deep Learning}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-11 %A Casas, Pedro %A Wassermann, Sarah %A Seufert, Michael %A Wehner, Nikolas %A Dinica, Olivia %A Hoßfeld, Tobias %B Network Traffic Measurement and Analysis Conference (TMA) %D 2022 %T X-Ray Goggles for the ISP: Improving in-Network Web and App QoE Monitoring with Deep Learning %X The wide adoption of end-to-end encryption is drastically limiting the visibility Internet Service Providers (ISPs) have on the performance of the services consumed by their customers. In times of strong competition, where customer experience plays a key role in churn management, ISPs require novel solutions enabling network-wide Quality of Experience (QoE) monitoring. To this end, we present DeepQoE, a deep-learning based approach to infer the QoE of web services and mobile applications from the ISP perspective, relying exclusively on the analysis of encrypted network traffic. Using raw features derived from the encrypted stream of bytes as input to deep Convolutional Neural Networks (CNNs), DeepQoE infers the Speed Index of web browsing sessions and general mobile apps with unprecedented accuracy, improving the state of the art by more than 25%, and reducing the QoE inference error in terms of mean opinion scores by nearly 40%. DeepQoE implements a web fingerprinting solution to identify individual web browsing sessions within concurrent web pages traffic, enabling highly detailed, per web page QoE inference in practical deployments. Extensive evaluations over a large and heterogeneous dataset composed of web and app measurements, using different device types and for top-popular websites and apps, confirm the out-performance of DeepQoE over previously used shallow-learning models, as well as the deep-model generalization to different devices, web pages, apps, and network setups. DeepQoE is the first deployable system providing such a deep, highly-detailed QoE for individual web browsing and mobile apps over encrypted traffic, using deep learning models on heterogeneous measurements.
• Simulative Performance Study of Slotted Aloha for LoRaWAN Channel Access Loh, Frank; Mehling, Noah; Geißler, Stefan; Hoßfeld, Tobias in IEEE/IFIP Network Operations and Management Symposium (2022).
  • [ Abstract ]
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  Future Internet of Things deployments generate a multitude of new challenges and opportunities. While 5G networks promise massive throughput rates with ultra low delays, many verticals in the areas of Industry 4.0, Smart City, or Smart Agriculture only transmit tiny amounts of data and instead demand high energy efficiency. This is addressed by access technologies like Low Power Wide Area Networks being com- plementary to high performance 5G networks. Especially Long Range Wide Area Network (LoRaWAN) promises transmissions across long distances with low energy requirements with the drawback of unreliable transmission due to potential message collisions through random channel access. For that reason, a broad parameter study simulation for LoRaWAN channel access with slotted Aloha is presented for real world scenarios and influences like clock drifts or cross traffic. The key impact factors of this channel access approach are studied with focus on the collision probability in various scenarios and simulation results are compared to the current state of the art. The contribution of this work are guidelines for parameter settings in a LoRaWAN with slotted Aloha channel access and performance comparisons for different settings. This information is crucial to scale and operate future LoRaWANs.

  @inproceedings{info3-article-2022-13, abstract = {Future Internet of Things deployments generate a multitude of new challenges and opportunities. While 5G networks promise massive throughput rates with ultra low delays, many verticals in the areas of Industry 4.0, Smart City, or Smart Agriculture only transmit tiny amounts of data and instead demand high energy efficiency. This is addressed by access technologies like Low Power Wide Area Networks being com- plementary to high performance 5G networks. Especially Long Range Wide Area Network (LoRaWAN) promises transmissions across long distances with low energy requirements with the drawback of unreliable transmission due to potential message collisions through random channel access. For that reason, a broad parameter study simulation for LoRaWAN channel access with slotted Aloha is presented for real world scenarios and influences like clock drifts or cross traffic. The key impact factors of this channel access approach are studied with focus on the collision probability in various scenarios and simulation results are compared to the current state of the art. The contribution of this work are guidelines for parameter settings in a LoRaWAN with slotted Aloha channel access and performance comparisons for different settings. This information is crucial to scale and operate future LoRaWANs.}, author = {Loh, Frank and Mehling, Noah and Geißler, Stefan and Hoßfeld, Tobias}, booktitle = {IEEE/IFIP Network Operations and Management Symposium}, keywords = {can}, month = 4, title = {Simulative Performance Study of Slotted Aloha for LoRaWAN Channel Access}, year = 2022 }

  %0 Conference Paper %1 info3-article-2022-13 %A Loh, Frank %A Mehling, Noah %A Geißler, Stefan %A Hoßfeld, Tobias %B IEEE/IFIP Network Operations and Management Symposium %D 2022 %T Simulative Performance Study of Slotted Aloha for LoRaWAN Channel Access %X Future Internet of Things deployments generate a multitude of new challenges and opportunities. While 5G networks promise massive throughput rates with ultra low delays, many verticals in the areas of Industry 4.0, Smart City, or Smart Agriculture only transmit tiny amounts of data and instead demand high energy efficiency. This is addressed by access technologies like Low Power Wide Area Networks being com- plementary to high performance 5G networks. Especially Long Range Wide Area Network (LoRaWAN) promises transmissions across long distances with low energy requirements with the drawback of unreliable transmission due to potential message collisions through random channel access. For that reason, a broad parameter study simulation for LoRaWAN channel access with slotted Aloha is presented for real world scenarios and influences like clock drifts or cross traffic. The key impact factors of this channel access approach are studied with focus on the collision probability in various scenarios and simulation results are compared to the current state of the art. The contribution of this work are guidelines for parameter settings in a LoRaWAN with slotted Aloha channel access and performance comparisons for different settings. This information is crucial to scale and operate future LoRaWANs.
• Characterizing Mobile Signaling Anomalies in the Internet-of-Things Vomhoff, Viktoria; Geißler, Stefan; Loh, Frank; Bauer, Wolfgang; Hoßfeld, Tobias in 2nd IFIP/IEEE International workshop on Fully-Flexible Internet Architectures and Protocols for the Next-Generation Tactile Internet (FlexNGIA) (2022).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  The development and adoption speed of new Internet of Things (IoT) devices and applications is constantly increasing. In particular in mobile networks, however, constant connectivity for all newly developed, globally spread, and occasionally geographically mobile devices is challenging. While the main business of current network operators is in particular, not to roam these new device generation between different networks, whereas new so-called Mobile Virtual Network Operators (MVNOs) arise with exactly this business case. They use already available Radio Access Networks and deploy SIM cards that are able to establish data connection everywhere on the basis of international roaming agreements. However, because of the complex interconnection of different systems, additional challenges arise. Outages in one network component might impact the whole system. In this work, we study these signaling anomalies called incidents based on a dataset received from a global MVNO. The goal of this work is to determine traffic characteristics during these incidents towards a better understanding of signaling traffic in IoT networks. Thus, this work can be seen as a fundamental basis to help operators in a characterization, and in particular prediction and avoidance of signaling incidents.

  @inproceedings{info3-inproceedings-2022-4, abstract = {The development and adoption speed of new Internet of Things (IoT) devices and applications is constantly increasing. In particular in mobile networks, however, constant connectivity for all newly developed, globally spread, and occasionally geographically mobile devices is challenging. While the main business of current network operators is in particular, not to roam these new device generation between different networks, whereas new so-called Mobile Virtual Network Operators (MVNOs) arise with exactly this business case. They use already available Radio Access Networks and deploy SIM cards that are able to establish data connection everywhere on the basis of international roaming agreements. However, because of the complex interconnection of different systems, additional challenges arise. Outages in one network component might impact the whole system. In this work, we study these signaling anomalies called incidents based on a dataset received from a global MVNO. The goal of this work is to determine traffic characteristics during these incidents towards a better understanding of signaling traffic in IoT networks. Thus, this work can be seen as a fundamental basis to help operators in a characterization, and in particular prediction and avoidance of signaling incidents.}, author = {Vomhoff, Viktoria and Geißler, Stefan and Loh, Frank and Bauer, Wolfgang and Hoßfeld, Tobias}, booktitle = {2nd IFIP/IEEE International workshop on Fully-Flexible Internet Architectures and Protocols for the Next-Generation Tactile Internet (FlexNGIA)}, keywords = {can}, month = 4, title = {Characterizing Mobile Signaling Anomalies in the Internet-of-Things}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-4 %A Vomhoff, Viktoria %A Geißler, Stefan %A Loh, Frank %A Bauer, Wolfgang %A Hoßfeld, Tobias %B 2nd IFIP/IEEE International workshop on Fully-Flexible Internet Architectures and Protocols for the Next-Generation Tactile Internet (FlexNGIA) %D 2022 %T Characterizing Mobile Signaling Anomalies in the Internet-of-Things %X The development and adoption speed of new Internet of Things (IoT) devices and applications is constantly increasing. In particular in mobile networks, however, constant connectivity for all newly developed, globally spread, and occasionally geographically mobile devices is challenging. While the main business of current network operators is in particular, not to roam these new device generation between different networks, whereas new so-called Mobile Virtual Network Operators (MVNOs) arise with exactly this business case. They use already available Radio Access Networks and deploy SIM cards that are able to establish data connection everywhere on the basis of international roaming agreements. However, because of the complex interconnection of different systems, additional challenges arise. Outages in one network component might impact the whole system. In this work, we study these signaling anomalies called incidents based on a dataset received from a global MVNO. The goal of this work is to determine traffic characteristics during these incidents towards a better understanding of signaling traffic in IoT networks. Thus, this work can be seen as a fundamental basis to help operators in a characterization, and in particular prediction and avoidance of signaling incidents.
• ML-based Performance Prediction of SDN using Simulated Data from Real and Synthetic Networks Dietz, Katharina; Gray, Nicholas; Seufert, Michael; Hoßfeld, Tobias in 33th IEEE/IFIP Network Operations and Management Symposium (NOMS) (2022).
  • [ BibTeX ]
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  @inproceedings{info3-inproceedings-2022-2, address = {Budapest, Hungary}, author = {Dietz, Katharina and Gray, Nicholas and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {33th IEEE/IFIP Network Operations and Management Symposium (NOMS)}, keywords = {ucn}, month = 4, title = {ML-based Performance Prediction of SDN using Simulated Data from Real and Synthetic Networks}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-2 %A Dietz, Katharina %A Gray, Nicholas %A Seufert, Michael %A Hoßfeld, Tobias %B 33th IEEE/IFIP Network Operations and Management Symposium (NOMS) %C Budapest, Hungary %D 2022 %T ML-based Performance Prediction of SDN using Simulated Data from Real and Synthetic Networks
• Analytical Model for the Energy Efficiency in Low Power IoT Deployments Hoßfeld, Tobias; Raffeck, Simon; Loh, Frank; Geißler, Stefan in 1st International Workshop on Network Energy Efficiency in the Softwarization Era (2022).
  • [ Abstract ]
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  The recent rise of the Internet of Things (IoT) has given way to numerous challenges and research questions. One of the most critical issues in the area of low powered devices is the question of energy efficiency. Here, technologies like LoRa or Zigbee emerged, promising low power consumption while maintaining adequate performance. However, even when using these tailor made technologies, several configuration aspects need to be taken into account to provide high performance, energy efficient operation. To this end, we propose a generic model to compute the energy efficiency of wireless sensors under the assumption of perfect CSMA/CA channel access. We present numerical results for a typical LoRa device and highlight extensions towards other channel access mechanisms. Finally, we apply Kleinrock's power metric to obtain ideal system configurations for varying load parameters.

  @inproceedings{info3-inproceedings-2022-6, abstract = {The recent rise of the Internet of Things (IoT) has given way to numerous challenges and research questions. One of the most critical issues in the area of low powered devices is the question of energy efficiency. Here, technologies like LoRa or Zigbee emerged, promising low power consumption while maintaining adequate performance. However, even when using these tailor made technologies, several configuration aspects need to be taken into account to provide high performance, energy efficient operation. To this end, we propose a generic model to compute the energy efficiency of wireless sensors under the assumption of perfect CSMA/CA channel access. We present numerical results for a typical LoRa device and highlight extensions towards other channel access mechanisms. Finally, we apply Kleinrock's power metric to obtain ideal system configurations for varying load parameters.}, author = {Hoßfeld, Tobias and Raffeck, Simon and Loh, Frank and Geißler, Stefan}, booktitle = {1st International Workshop on Network Energy Efficiency in the Softwarization Era}, keywords = {can}, month = 6, title = {Analytical Model for the Energy Efficiency in Low Power IoT Deployments}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-6 %A Hoßfeld, Tobias %A Raffeck, Simon %A Loh, Frank %A Geißler, Stefan %B 1st International Workshop on Network Energy Efficiency in the Softwarization Era %D 2022 %T Analytical Model for the Energy Efficiency in Low Power IoT Deployments %X The recent rise of the Internet of Things (IoT) has given way to numerous challenges and research questions. One of the most critical issues in the area of low powered devices is the question of energy efficiency. Here, technologies like LoRa or Zigbee emerged, promising low power consumption while maintaining adequate performance. However, even when using these tailor made technologies, several configuration aspects need to be taken into account to provide high performance, energy efficient operation. To this end, we propose a generic model to compute the energy efficiency of wireless sensors under the assumption of perfect CSMA/CA channel access. We present numerical results for a typical LoRa device and highlight extensions towards other channel access mechanisms. Finally, we apply Kleinrock's power metric to obtain ideal system configurations for varying load parameters.
• DBM: Decentralized Burst Mitigation for Self-Organizing LoRa Deployments Raffeck, Simon; Geißler, Stefan; Hoßfeld, Tobias in KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2022 (2022).
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  @inproceedings{info3-inproceedings-2022-7, author = {Raffeck, Simon and Geißler, Stefan and Hoßfeld, Tobias}, booktitle = {KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2022}, keywords = {can}, month = 7, title = {DBM: Decentralized Burst Mitigation for Self-Organizing LoRa Deployments}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-7 %A Raffeck, Simon %A Geißler, Stefan %A Hoßfeld, Tobias %B KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2022 %D 2022 %T DBM: Decentralized Burst Mitigation for Self-Organizing LoRa Deployments
• Generic Model to Quantify Energy Consumption for Different LoRaWAN Channel Access Methods Loh, Frank; Raffeck, Simon; Geißler, Stefan; Hoßfeld, Tobias in 18th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob) (2022).
  • [ Abstract ]
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  LoRaWAN is one of the most promising Internet of Things technologies with regard to low energy consumption. However, the currently used random channel access has much potential for improvement. Thus, current literature studies alternative channel access approaches, but the energy consumption is often not taken into consideration. For that reason, we present a generic model to quantify energy consumption in LoRaWAN for different channel access mechanisms based on a state machine. With our model, we can describe the energy consumption for specific access mechanisms or for the complete network. Our model shows that random access only performs best if no additional receive windows are opened. A simple improvement is Listen before Talk. For networks with high load, improvements are achieved by a more complex scheduled MAC. Our model serves as a basis for future energy consumption studies, conducted through measurements or simulations.

  @inproceedings{info3-inproceedings-2022-21, abstract = {LoRaWAN is one of the most promising Internet of Things technologies with regard to low energy consumption. However, the currently used random channel access has much potential for improvement. Thus, current literature studies alternative channel access approaches, but the energy consumption is often not taken into consideration. For that reason, we present a generic model to quantify energy consumption in LoRaWAN for different channel access mechanisms based on a state machine. With our model, we can describe the energy consumption for specific access mechanisms or for the complete network. Our model shows that random access only performs best if no additional receive windows are opened. A simple improvement is Listen before Talk. For networks with high load, improvements are achieved by a more complex scheduled MAC. Our model serves as a basis for future energy consumption studies, conducted through measurements or simulations.}, author = {Loh, Frank and Raffeck, Simon and Geißler, Stefan and Hoßfeld, Tobias}, booktitle = {18th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)}, keywords = {5mart}, month = 10, title = {Generic Model to Quantify Energy Consumption for Different LoRaWAN Channel Access Methods}, year = 2022 }

  %0 Conference Paper %1 info3-inproceedings-2022-21 %A Loh, Frank %A Raffeck, Simon %A Geißler, Stefan %A Hoßfeld, Tobias %B 18th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob) %D 2022 %T Generic Model to Quantify Energy Consumption for Different LoRaWAN Channel Access Methods %X LoRaWAN is one of the most promising Internet of Things technologies with regard to low energy consumption. However, the currently used random channel access has much potential for improvement. Thus, current literature studies alternative channel access approaches, but the energy consumption is often not taken into consideration. For that reason, we present a generic model to quantify energy consumption in LoRaWAN for different channel access mechanisms based on a state machine. With our model, we can describe the energy consumption for specific access mechanisms or for the complete network. Our model shows that random access only performs best if no additional receive windows are opened. A simple improvement is Listen before Talk. For networks with high load, improvements are achieved by a more complex scheduled MAC. Our model serves as a basis for future energy consumption studies, conducted through measurements or simulations.

• Talk to Me: Investigating the Traffic Characteristics of Amazon Echo Dot and Google Home Loh, Frank; Geissler, Stefan; Schaible, Fabian; Hoßfeld, Tobias in International Conference on Communications and Electronics, ICCE (2021).
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  The application area of smart speakers is steadily increasing with the Amazon Echo family and Google Home being brand leaders. Use cases include, among others, updating the calendar, home automation, or simply assisting users in their every day life. With the increasing amount of devices, the traffic generation and requesting process becomes a relevant subject to be studied in order to create traffic models and predict the impact on networks by these types of devices. Furthermore, with a detailed understanding of the devices, service quality can be monitored and improved for the end user. For that reason, in this work the requesting and traffic generation process of the Amazon Echo Dot and Google Home are studied and the generated network load of both devices is compared. With the insights of this study and additional device usage statistics, detailed traffic and usage models can be created.

  @inproceedings{info3-inproceedings-2021-5, abstract = {The application area of smart speakers is steadily increasing with the Amazon Echo family and Google Home being brand leaders. Use cases include, among others, updating the calendar, home automation, or simply assisting users in their every day life. With the increasing amount of devices, the traffic generation and requesting process becomes a relevant subject to be studied in order to create traffic models and predict the impact on networks by these types of devices. Furthermore, with a detailed understanding of the devices, service quality can be monitored and improved for the end user. For that reason, in this work the requesting and traffic generation process of the Amazon Echo Dot and Google Home are studied and the generated network load of both devices is compared. With the insights of this study and additional device usage statistics, detailed traffic and usage models can be created.}, author = {Loh, Frank and Geissler, Stefan and Schaible, Fabian and Hoßfeld, Tobias}, booktitle = {International Conference on Communications and Electronics, ICCE}, keywords = {sys:hidden:inproceedings}, month = 1, title = {Talk to Me: Investigating the Traffic Characteristics of Amazon Echo Dot and Google Home}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-5 %A Loh, Frank %A Geissler, Stefan %A Schaible, Fabian %A Hoßfeld, Tobias %B International Conference on Communications and Electronics, ICCE %D 2021 %T Talk to Me: Investigating the Traffic Characteristics of Amazon Echo Dot and Google Home %X The application area of smart speakers is steadily increasing with the Amazon Echo family and Google Home being brand leaders. Use cases include, among others, updating the calendar, home automation, or simply assisting users in their every day life. With the increasing amount of devices, the traffic generation and requesting process becomes a relevant subject to be studied in order to create traffic models and predict the impact on networks by these types of devices. Furthermore, with a detailed understanding of the devices, service quality can be monitored and improved for the end user. For that reason, in this work the requesting and traffic generation process of the Amazon Echo Dot and Google Home are studied and the generated network load of both devices is compared. With the insights of this study and additional device usage statistics, detailed traffic and usage models can be created.
• QoE Models in the Wild: Comparing Video QoE Models Using a Crowdsourced Data Set Seufert, Anika; Wamser, Florian; Yarish, David; Macdonald, Hunter; Hoßfeld, Tobias in 2021 13th International Conference on Quality of Multimedia Experience (QoMEX) (2021).
  • [ Abstract ]
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  Crowdsourced measurements solve the problem of being able to assess the performance of a communication network from an end-user perspective, but the new characteristics of the data pose new challenges for QoE modeling. In contrast to existing laboratory or network measurements, this type of measurement at the end-user device primarily involves taking a large number of short sample measurements, which, however, are rich in measured parameters, including many user-, application-, and device-related parameters. To test the applicability and to facilitate the integration of such data, we applied four QoE models from the literature to 290k worldwide video streaming measurements from a commercial data set from August to October 2020. In this work, we will therefore first describe the crowdsourcing video streaming data set to provide insights into the properties of video streaming KPIs in the real-world. Second, we run four popular QoE models using this data set, compare the resulting QoE scores, and derive the impact of individual KPIs for each model. We show that the models assess the QoE at least differently, but sometimes with contradicting statements. Reading this paper, it becomes evident that more work and subjective studies, based on real-world data like the one we have shown, are needed to extend the current QoE models.

  @inproceedings{info3-inproceedings-2021-12, abstract = {Crowdsourced measurements solve the problem of being able to assess the performance of a communication network from an end-user perspective, but the new characteristics of the data pose new challenges for QoE modeling. In contrast to existing laboratory or network measurements, this type of measurement at the end-user device primarily involves taking a large number of short sample measurements, which, however, are rich in measured parameters, including many user-, application-, and device-related parameters. To test the applicability and to facilitate the integration of such data, we applied four QoE models from the literature to 290k worldwide video streaming measurements from a commercial data set from August to October 2020. In this work, we will therefore first describe the crowdsourcing video streaming data set to provide insights into the properties of video streaming KPIs in the real-world. Second, we run four popular QoE models using this data set, compare the resulting QoE scores, and derive the impact of individual KPIs for each model. We show that the models assess the QoE at least differently, but sometimes with contradicting statements. Reading this paper, it becomes evident that more work and subjective studies, based on real-world data like the one we have shown, are needed to extend the current QoE models.}, address = {Montreal, Canada (virtual conference)}, author = {Seufert, Anika and Wamser, Florian and Yarish, David and Macdonald, Hunter and Hoßfeld, Tobias}, booktitle = {2021 13th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {can}, month = 6, title = {QoE Models in the Wild: Comparing Video QoE Models Using a Crowdsourced Data Set}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-12 %A Seufert, Anika %A Wamser, Florian %A Yarish, David %A Macdonald, Hunter %A Hoßfeld, Tobias %B 2021 13th International Conference on Quality of Multimedia Experience (QoMEX) %C Montreal, Canada (virtual conference) %D 2021 %T QoE Models in the Wild: Comparing Video QoE Models Using a Crowdsourced Data Set %X Crowdsourced measurements solve the problem of being able to assess the performance of a communication network from an end-user perspective, but the new characteristics of the data pose new challenges for QoE modeling. In contrast to existing laboratory or network measurements, this type of measurement at the end-user device primarily involves taking a large number of short sample measurements, which, however, are rich in measured parameters, including many user-, application-, and device-related parameters. To test the applicability and to facilitate the integration of such data, we applied four QoE models from the literature to 290k worldwide video streaming measurements from a commercial data set from August to October 2020. In this work, we will therefore first describe the crowdsourcing video streaming data set to provide insights into the properties of video streaming KPIs in the real-world. Second, we run four popular QoE models using this data set, compare the resulting QoE scores, and derive the impact of individual KPIs for each model. We show that the models assess the QoE at least differently, but sometimes with contradicting statements. Reading this paper, it becomes evident that more work and subjective studies, based on real-world data like the one we have shown, are needed to extend the current QoE models.
• Machine Learning-based Service Function Chain over UAVs: Resource Profiling and Framework TrungKien, Nguyen; Hoang Anh, Vu; Dinh Phong, Vu; Ngoc Minh, Nguyen; Huu Thanh, Nguyen in 2021 31st International Telecommunication Networks and Applications Conference (ITNAC) (2021).
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  @inproceedings{info3-inproceedings-2021-21, address = {Sydney, Australia}, author = {TrungKien, Nguyen and Hoang Anh, Vu and Dinh Phong, Vu and Ngoc Minh, Nguyen and Huu Thanh, Nguyen}, booktitle = {2021 31st International Telecommunication Networks and Applications Conference (ITNAC)}, keywords = {sys:hidden:inproceedings}, month = 11, title = {Machine Learning-based Service Function Chain over UAVs: Resource Profiling and Framework}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-21 %A TrungKien, Nguyen %A Hoang Anh, Vu %A Dinh Phong, Vu %A Ngoc Minh, Nguyen %A Huu Thanh, Nguyen %B 2021 31st International Telecommunication Networks and Applications Conference (ITNAC) %C Sydney, Australia %D 2021 %T Machine Learning-based Service Function Chain over UAVs: Resource Profiling and Framework
• Machine-Learning Based Prediction of Next HTTP Request Arrival Time in Adaptive Video Streaming Pimpinella, Andrea; Redondi, Alessandro E.C.; Loh, Frank; Seufert, Michael in 3rd International Workshop on High-Precision, Predictable, and Low-Latency Networking (HiPNet) (2021).
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  @inproceedings{info3-inproceedings-2021-18, address = {Izmir, Turkey (Virtual Conference)}, author = {Pimpinella, Andrea and Redondi, Alessandro E.C. and Loh, Frank and Seufert, Michael}, booktitle = {3rd International Workshop on High-Precision, Predictable, and Low-Latency Networking (HiPNet)}, keywords = {ucn}, month = 10, title = {Machine-Learning Based Prediction of Next HTTP Request Arrival Time in Adaptive Video Streaming}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-18 %A Pimpinella, Andrea %A Redondi, Alessandro E.C. %A Loh, Frank %A Seufert, Michael %B 3rd International Workshop on High-Precision, Predictable, and Low-Latency Networking (HiPNet) %C Izmir, Turkey (Virtual Conference) %D 2021 %T Machine-Learning Based Prediction of Next HTTP Request Arrival Time in Adaptive Video Streaming
• Mobile Web and App QoE Monitoring for ISPs - from Encrypted Traffic to Speed Index through Machine Learning Casas, Pedro; Wassermann, Sarah; Wehner, Nikolas; Seufert, Michael; Schüler, Joshua; Hoßfeld, Tobias in 13th Wireless and Mobile Networking Conference (WMNC), Best Paper Award (2021).
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  @inproceedings{info3-inproceedings-2021-17, address = {Montreal, Canada (Virtual Conference)}, author = {Casas, Pedro and Wassermann, Sarah and Wehner, Nikolas and Seufert, Michael and Schüler, Joshua and Hoßfeld, Tobias}, booktitle = {13th Wireless and Mobile Networking Conference (WMNC), Best Paper Award}, keywords = {ucn}, month = 10, title = {Mobile Web and App QoE Monitoring for ISPs - from Encrypted Traffic to Speed Index through Machine Learning}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-17 %A Casas, Pedro %A Wassermann, Sarah %A Wehner, Nikolas %A Seufert, Michael %A Schüler, Joshua %A Hoßfeld, Tobias %B 13th Wireless and Mobile Networking Conference (WMNC), Best Paper Award %C Montreal, Canada (Virtual Conference) %D 2021 %T Mobile Web and App QoE Monitoring for ISPs - from Encrypted Traffic to Speed Index through Machine Learning
• Browser Fingerprinting: How to Protect Machine Learning Models and Data with Differential Privacy? Dietz, Katharina; Mühlhauser, Michael; Seufert, Michael; Gray, Nicholas; Hoßfeld, Tobias; Herrmann, Dominik in 1st International Workshop on Machine Learning in Networking (MaLeNe) (2021).
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  @inproceedings{info3-inproceedings-2021-16, address = {Lübeck, Germany (Virtual Conference)}, author = {Dietz, Katharina and Mühlhauser, Michael and Seufert, Michael and Gray, Nicholas and Hoßfeld, Tobias and Herrmann, Dominik}, booktitle = {1st International Workshop on Machine Learning in Networking (MaLeNe)}, keywords = {ucn}, month = 9, title = {Browser Fingerprinting: How to Protect Machine Learning Models and Data with Differential Privacy?}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-16 %A Dietz, Katharina %A Mühlhauser, Michael %A Seufert, Michael %A Gray, Nicholas %A Hoßfeld, Tobias %A Herrmann, Dominik %B 1st International Workshop on Machine Learning in Networking (MaLeNe) %C Lübeck, Germany (Virtual Conference) %D 2021 %T Browser Fingerprinting: How to Protect Machine Learning Models and Data with Differential Privacy?
• How are your Apps Doing? QoE Inference and Analysis in Mobile Devices Wehner, Nikolas; Seufert, Michael; Schüler, Joshua; Casas, Pedro; Hoßfeld, Tobias in 17th International Conference on Network and Service Management (CNSM) (2021).
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  Web browsing has become the most important application of the Internet for the end user. When it comes to mobile devices, web services are mainly accessed through apps. This paper tackles the problem of Web Quality of Experience (QoE) in mobile devices, with a specific focus on apps QoE monitoring and analysis, using in-network (encrypted) traffic measurements. Measuring apps QoE is complex, not only from an instrumentation point of view, but also from the heterogeneity of user interactions which might realize substantially different user experience. To this end, we conduct a feasibility study on four specific and popular Android apps and their corresponding web services. Our test automation framework emulates and measures different user interactions commonly executed during an app session, including the app startup, clicking, scrolling, and searching. The resulting traffic is characterized on different dimensions, and machine learning models are trained to identify web services, apps, and user interactions, and to infer their QoE. The proposed models can correctly identify the specific web service and app in 86% of the cases and accurately estimate the associated QoE with small errors. Our preliminary study represents a first step towards an in-network, web QoE monitoring solution for mobile-device apps.

  @inproceedings{info3-inproceedings-2021-15, abstract = {Web browsing has become the most important application of the Internet for the end user. When it comes to mobile devices, web services are mainly accessed through apps. This paper tackles the problem of Web Quality of Experience (QoE) in mobile devices, with a specific focus on apps QoE monitoring and analysis, using in-network (encrypted) traffic measurements. Measuring apps QoE is complex, not only from an instrumentation point of view, but also from the heterogeneity of user interactions which might realize substantially different user experience. To this end, we conduct a feasibility study on four specific and popular Android apps and their corresponding web services. Our test automation framework emulates and measures different user interactions commonly executed during an app session, including the app startup, clicking, scrolling, and searching. The resulting traffic is characterized on different dimensions, and machine learning models are trained to identify web services, apps, and user interactions, and to infer their QoE. The proposed models can correctly identify the specific web service and app in 86% of the cases and accurately estimate the associated QoE with small errors. Our preliminary study represents a first step towards an in-network, web QoE monitoring solution for mobile-device apps.}, address = {Izmir, Turkey (Virtual Conference)}, author = {Wehner, Nikolas and Seufert, Michael and Schüler, Joshua and Casas, Pedro and Hoßfeld, Tobias}, booktitle = {17th International Conference on Network and Service Management (CNSM)}, keywords = {ucn}, month = 10, title = {How are your Apps Doing? QoE Inference and Analysis in Mobile Devices}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-15 %A Wehner, Nikolas %A Seufert, Michael %A Schüler, Joshua %A Casas, Pedro %A Hoßfeld, Tobias %B 17th International Conference on Network and Service Management (CNSM) %C Izmir, Turkey (Virtual Conference) %D 2021 %T How are your Apps Doing? QoE Inference and Analysis in Mobile Devices %X Web browsing has become the most important application of the Internet for the end user. When it comes to mobile devices, web services are mainly accessed through apps. This paper tackles the problem of Web Quality of Experience (QoE) in mobile devices, with a specific focus on apps QoE monitoring and analysis, using in-network (encrypted) traffic measurements. Measuring apps QoE is complex, not only from an instrumentation point of view, but also from the heterogeneity of user interactions which might realize substantially different user experience. To this end, we conduct a feasibility study on four specific and popular Android apps and their corresponding web services. Our test automation framework emulates and measures different user interactions commonly executed during an app session, including the app startup, clicking, scrolling, and searching. The resulting traffic is characterized on different dimensions, and machine learning models are trained to identify web services, apps, and user interactions, and to infer their QoE. The proposed models can correctly identify the specific web service and app in 86% of the cases and accurately estimate the associated QoE with small errors. Our preliminary study represents a first step towards an in-network, web QoE monitoring solution for mobile-device apps.
• Relationship Status: It’s Complicated. Using APM as a QoE-qualifying Tempo Metric Metzger, Florian; Stulier, Norman; Borchert, Kathrin; Hirth, Matthias in Proceedings of the 13th International Conference on Quality of Multimedia Experience (QoMEX 2021) (2021).
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  @inproceedings{info3-inproceedings-2021-13, author = {Metzger, Florian and Stulier, Norman and Borchert, Kathrin and Hirth, Matthias}, booktitle = {Proceedings of the 13th International Conference on Quality of Multimedia Experience (QoMEX 2021)}, keywords = {sys:hidden:inproceedings}, month = 6, title = {Relationship Status: It's Complicated. Using APM as a QoE-qualifying Tempo Metric}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-13 %A Metzger, Florian %A Stulier, Norman %A Borchert, Kathrin %A Hirth, Matthias %B Proceedings of the 13th International Conference on Quality of Multimedia Experience (QoMEX 2021) %D 2021 %T Relationship Status: It's Complicated. Using APM as a QoE-qualifying Tempo Metric
• Robust Gateway Placement for Scalable LoRaWAN Loh, Frank; Bau, Dominique; Zink, Johannes; Wolff, Alexander; Hoßfeld, Tobias in 13th IFIP Wireless and Mobile Networking Conference (WMNC) (2021).
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  Many exciting applications are currently emerging due to the use of technology from the Internet of Things (IoT) in Smart Cities. In recent years, Long Range Wide Area Networks (LoRaWANs) have become one of the main technologies in this field due to long distance coverage, low power consumption sensors, and economic reasons. So far, LoRaWANs have been planned and deployed mainly with the aim of minimizing the number of gateways, while still providing coverage in a geographic area. Packet collisions and future traffic have not been considered. In contrast, we present a gateway placement strategy that is robust against an increase in the number of sensors and in the network load. To this end, we modify an existing local search algorithm for a geometric set cover problem such that it takes the capacities of gateways into account. If we set these capacities below the maximum, the network can accommodate additional sensors in the future. Moreover, our algorithm can extend the initial placement once the capacities are exhausted.

  @inproceedings{info3-inproceedings-2021-20, abstract = {Many exciting applications are currently emerging due to the use of technology from the Internet of Things (IoT) in Smart Cities. In recent years, Long Range Wide Area Networks (LoRaWANs) have become one of the main technologies in this field due to long distance coverage, low power consumption sensors, and economic reasons. So far, LoRaWANs have been planned and deployed mainly with the aim of minimizing the number of gateways, while still providing coverage in a geographic area. Packet collisions and future traffic have not been considered. In contrast, we present a gateway placement strategy that is robust against an increase in the number of sensors and in the network load. To this end, we modify an existing local search algorithm for a geometric set cover problem such that it takes the capacities of gateways into account. If we set these capacities below the maximum, the network can accommodate additional sensors in the future. Moreover, our algorithm can extend the initial placement once the capacities are exhausted.}, author = {Loh, Frank and Bau, Dominique and Zink, Johannes and Wolff, Alexander and Hoßfeld, Tobias}, booktitle = {13th IFIP Wireless and Mobile Networking Conference (WMNC)}, keywords = {5mart}, month = 10, title = {Robust Gateway Placement for Scalable LoRaWAN}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-20 %A Loh, Frank %A Bau, Dominique %A Zink, Johannes %A Wolff, Alexander %A Hoßfeld, Tobias %B 13th IFIP Wireless and Mobile Networking Conference (WMNC) %D 2021 %T Robust Gateway Placement for Scalable LoRaWAN %X Many exciting applications are currently emerging due to the use of technology from the Internet of Things (IoT) in Smart Cities. In recent years, Long Range Wide Area Networks (LoRaWANs) have become one of the main technologies in this field due to long distance coverage, low power consumption sensors, and economic reasons. So far, LoRaWANs have been planned and deployed mainly with the aim of minimizing the number of gateways, while still providing coverage in a geographic area. Packet collisions and future traffic have not been considered. In contrast, we present a gateway placement strategy that is robust against an increase in the number of sensors and in the network load. To this end, we modify an existing local search algorithm for a geometric set cover problem such that it takes the capacities of gateways into account. If we set these capacities below the maximum, the network can accommodate additional sensors in the future. Moreover, our algorithm can extend the initial placement once the capacities are exhausted.
• On Machine Learning based Video QoE Estimation Across Different Networks Orsolic, Irena; Seufert, Michael in 16th International Conference on Telecommunications (ConTEL), Best Paper Award (2021).
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  @inproceedings{info3-inproceedings-2021-10, address = {Zagreb, Croatia (Virtual Conference)}, author = {Orsolic, Irena and Seufert, Michael}, booktitle = {16th International Conference on Telecommunications (ConTEL), Best Paper Award}, keywords = {ucn}, month = 7, title = {On Machine Learning based Video QoE Estimation Across Different Networks}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-10 %A Orsolic, Irena %A Seufert, Michael %B 16th International Conference on Telecommunications (ConTEL), Best Paper Award %C Zagreb, Croatia (Virtual Conference) %D 2021 %T On Machine Learning based Video QoE Estimation Across Different Networks
• High Performance Network Metadata Extraction Using P4 for ML-Based Intrusion Detection Systems Gray, Nicholas; Dietz, Katharina; Seufert, Michael; Hoßfeld, Tobias in 22nd International Conference on High Performance Switching and Routing (HPSR) (2021).
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  @inproceedings{info3-inproceedings-2021-8, address = {Paris, France (Virtual Conference)}, author = {Gray, Nicholas and Dietz, Katharina and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {22nd International Conference on High Performance Switching and Routing (HPSR)}, keywords = {ucn}, month = 6, title = {High Performance Network Metadata Extraction Using P4 for ML-Based Intrusion Detection Systems}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-8 %A Gray, Nicholas %A Dietz, Katharina %A Seufert, Michael %A Hoßfeld, Tobias %B 22nd International Conference on High Performance Switching and Routing (HPSR) %C Paris, France (Virtual Conference) %D 2021 %T High Performance Network Metadata Extraction Using P4 for ML-Based Intrusion Detection Systems
• On Inter-Rater Reliability for Crowdsourced QoE Hoßfeld, Tobias; Seufert, Michael; Naderi, Babak in 13th International Conference on Quality of Multimedia Experience (QoMEX) (2021).
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  @inproceedings{info3-inproceedings-2021-9, address = {Montreal, Canada (Virtual Conference)}, author = {Hoßfeld, Tobias and Seufert, Michael and Naderi, Babak}, booktitle = {13th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ucn}, month = 6, title = {On Inter-Rater Reliability for Crowdsourced QoE}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-9 %A Hoßfeld, Tobias %A Seufert, Michael %A Naderi, Babak %B 13th International Conference on Quality of Multimedia Experience (QoMEX) %C Montreal, Canada (Virtual Conference) %D 2021 %T On Inter-Rater Reliability for Crowdsourced QoE
• Signaling Traffic in Internet-of-Things Mobile Networks Geissler, Stefan; Wamser, Florian; Bauer, Wolfang; Krolikowski, Michael; Gebert, Steffen; Hoßfeld, Tobias in IFIP/IEEE International Symposium on Integrated Network Management (IM 2021) (2021).
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  The Internet of Things (IoT) is expected to play an increasingly important role in next-generation mobile networks. Detailed knowledge of this type of traffic and the associated signaling in those networks is of interest to operators and standardization in order to run these networks successfully. The aim of this study is to characterize IoT signaling traffic for mobile communication networks (i) from a network operator’s point of view, (ii) at device level, and (iii) for the establishment of data connections. General statistics on signaling and device behavior, such as the observed IoT traffic volume and message composition, are given before device classes with statistically different signaling behavior are identified. Finally, by characterizing the aggre- gated signaling traffic, we show that the Markov assumption, widespread in standardization and literature, regarding the aggregated arrival process for data connections does not apply in reality.

  @inproceedings{info3-inproceedings-2021-1, abstract = {The Internet of Things (IoT) is expected to play an increasingly important role in next-generation mobile networks. Detailed knowledge of this type of traffic and the associated signaling in those networks is of interest to operators and standardization in order to run these networks successfully. The aim of this study is to characterize IoT signaling traffic for mobile communication networks (i) from a network operator’s point of view, (ii) at device level, and (iii) for the establishment of data connections. General statistics on signaling and device behavior, such as the observed IoT traffic volume and message composition, are given before device classes with statistically different signaling behavior are identified. Finally, by characterizing the aggre- gated signaling traffic, we show that the Markov assumption, widespread in standardization and literature, regarding the aggregated arrival process for data connections does not apply in reality.}, address = {Bordeaux, France (Virtual Conference)}, author = {Geissler, Stefan and Wamser, Florian and Bauer, Wolfang and Krolikowski, Michael and Gebert, Steffen and Hoßfeld, Tobias}, booktitle = {IFIP/IEEE International Symposium on Integrated Network Management (IM 2021)}, keywords = {can}, month = 5, title = {Signaling Traffic in Internet-of-Things Mobile Networks}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-1 %A Geissler, Stefan %A Wamser, Florian %A Bauer, Wolfang %A Krolikowski, Michael %A Gebert, Steffen %A Hoßfeld, Tobias %B IFIP/IEEE International Symposium on Integrated Network Management (IM 2021) %C Bordeaux, France (Virtual Conference) %D 2021 %T Signaling Traffic in Internet-of-Things Mobile Networks %X The Internet of Things (IoT) is expected to play an increasingly important role in next-generation mobile networks. Detailed knowledge of this type of traffic and the associated signaling in those networks is of interest to operators and standardization in order to run these networks successfully. The aim of this study is to characterize IoT signaling traffic for mobile communication networks (i) from a network operator’s point of view, (ii) at device level, and (iii) for the establishment of data connections. General statistics on signaling and device behavior, such as the observed IoT traffic volume and message composition, are given before device classes with statistically different signaling behavior are identified. Finally, by characterizing the aggre- gated signaling traffic, we show that the Markov assumption, widespread in standardization and literature, regarding the aggregated arrival process for data connections does not apply in reality.
• Trust but Verify: Crowdsourced Mobile Network Measurements and Statistical Validity Measures Seufert, Anika; Wamser, Florian; Wunderer, Stefan; Hall, Andrew; Hoßfeld, Tobias in 2021 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit) (2021).
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  Network operators, regulators, and big data companies use crowdsourced measurements to study the performance of mobile networks on a large scale. Such a type of measurement is defined as the collection and processing of data measured by the crowd, here the crowd of mobile subscribers. Crowdsourced network measurements make it relatively easy and inexpensive to obtain large amounts of network data that also reflect the quality actually received by the end user. However, this measurement method also involves some uncertainties, since, for example, it is not possible to precisely control when, where and with which devices measurements are taken. Thus, there is a trade-off between the reliability of the individual measurement and the scope of the measurements. Therefore, how data of this type is analyzed is particularly important in order to obtain valid results. To address this issue, our paper defines concepts and guidelines for analyzing the validity of crowdsourced mobile network measurements. In particular, we address precision, for example the number of measurements needed to make valid statements, and also representativeness, for example the spatial and temporal distribution of the data. In addition to the formal definition of these two aspects, we illustrate the issue and possible evaluation approaches with the help of an extensive example data set. This data set consists of more than 11.7M crowdsourced mobile measurements from all over France, measured by a commercial mobile data provider. In the end, we provide an evaluation guideline and two possible use cases.

  @inproceedings{info3-inproceedings-2021-11, abstract = {Network operators, regulators, and big data companies use crowdsourced measurements to study the performance of mobile networks on a large scale. Such a type of measurement is defined as the collection and processing of data measured by the crowd, here the crowd of mobile subscribers. Crowdsourced network measurements make it relatively easy and inexpensive to obtain large amounts of network data that also reflect the quality actually received by the end user. However, this measurement method also involves some uncertainties, since, for example, it is not possible to precisely control when, where and with which devices measurements are taken. Thus, there is a trade-off between the reliability of the individual measurement and the scope of the measurements. Therefore, how data of this type is analyzed is particularly important in order to obtain valid results. To address this issue, our paper defines concepts and guidelines for analyzing the validity of crowdsourced mobile network measurements. In particular, we address precision, for example the number of measurements needed to make valid statements, and also representativeness, for example the spatial and temporal distribution of the data. In addition to the formal definition of these two aspects, we illustrate the issue and possible evaluation approaches with the help of an extensive example data set. This data set consists of more than 11.7M crowdsourced mobile measurements from all over France, measured by a commercial mobile data provider. In the end, we provide an evaluation guideline and two possible use cases.}, address = {Porto, Portugal (virtual conference)}, author = {Seufert, Anika and Wamser, Florian and Wunderer, Stefan and Hall, Andrew and Hoßfeld, Tobias}, booktitle = {2021 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit)}, keywords = {can}, month = 6, title = {Trust but Verify: Crowdsourced Mobile Network Measurements and Statistical Validity Measures}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-11 %A Seufert, Anika %A Wamser, Florian %A Wunderer, Stefan %A Hall, Andrew %A Hoßfeld, Tobias %B 2021 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit) %C Porto, Portugal (virtual conference) %D 2021 %T Trust but Verify: Crowdsourced Mobile Network Measurements and Statistical Validity Measures %X Network operators, regulators, and big data companies use crowdsourced measurements to study the performance of mobile networks on a large scale. Such a type of measurement is defined as the collection and processing of data measured by the crowd, here the crowd of mobile subscribers. Crowdsourced network measurements make it relatively easy and inexpensive to obtain large amounts of network data that also reflect the quality actually received by the end user. However, this measurement method also involves some uncertainties, since, for example, it is not possible to precisely control when, where and with which devices measurements are taken. Thus, there is a trade-off between the reliability of the individual measurement and the scope of the measurements. Therefore, how data of this type is analyzed is particularly important in order to obtain valid results. To address this issue, our paper defines concepts and guidelines for analyzing the validity of crowdsourced mobile network measurements. In particular, we address precision, for example the number of measurements needed to make valid statements, and also representativeness, for example the spatial and temporal distribution of the data. In addition to the formal definition of these two aspects, we illustrate the issue and possible evaluation approaches with the help of an extensive example data set. This data set consists of more than 11.7M crowdsourced mobile measurements from all over France, measured by a commercial mobile data provider. In the end, we provide an evaluation guideline and two possible use cases.
• Quality that Matters: QoE Monitoring in Education Service Provider (ESP) Networks Wehner, Nikolas; Seufert, Michael; Wieser, Viktoria; Casas, Pedro; Capdehourat, Germán in IFIP/IEEE International Symposium on Integrated Network Management (IM 2021) (2021).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Education Service Providers (ESPs) play a crucial role in the digitization of education as they equip students and teachers with reliable devices and provide high quality Internet access at schools. This paper investigates four months worth of continuous measurements conducted by an ESP using a largescale, passive, in-device Quality of Experience (QoE) monitoring system deployed into a nationwide network of education-purpose devices. These measurements cover more than 800 education centers and about 4000 devices, used both in schools and at home. Using this rich dataset, we present an exhaustive characterization of the browsing behavior, and a quantification of the web and video QoE in this educational context. Web QoE results showed a better performance for school Wi-Fi networks compared to home connections, suggesting that several issues may arise for ESPs due to the increasing relevance of home-schooling caused by the COVID-19 pandemic.

  @inproceedings{info3-inproceedings-2021-3, abstract = {Education Service Providers (ESPs) play a crucial role in the digitization of education as they equip students and teachers with reliable devices and provide high quality Internet access at schools. This paper investigates four months worth of continuous measurements conducted by an ESP using a largescale, passive, in-device Quality of Experience (QoE) monitoring system deployed into a nationwide network of education-purpose devices. These measurements cover more than 800 education centers and about 4000 devices, used both in schools and at home. Using this rich dataset, we present an exhaustive characterization of the browsing behavior, and a quantification of the web and video QoE in this educational context. Web QoE results showed a better performance for school Wi-Fi networks compared to home connections, suggesting that several issues may arise for ESPs due to the increasing relevance of home-schooling caused by the COVID-19 pandemic.}, address = {Bordeaux, France (Virtual Conference)}, author = {Wehner, Nikolas and Seufert, Michael and Wieser, Viktoria and Casas, Pedro and Capdehourat, Germán}, booktitle = {IFIP/IEEE International Symposium on Integrated Network Management (IM 2021)}, keywords = {ucn}, month = 5, title = {Quality that Matters: QoE Monitoring in Education Service Provider (ESP) Networks}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-3 %A Wehner, Nikolas %A Seufert, Michael %A Wieser, Viktoria %A Casas, Pedro %A Capdehourat, Germán %B IFIP/IEEE International Symposium on Integrated Network Management (IM 2021) %C Bordeaux, France (Virtual Conference) %D 2021 %T Quality that Matters: QoE Monitoring in Education Service Provider (ESP) Networks %X Education Service Providers (ESPs) play a crucial role in the digitization of education as they equip students and teachers with reliable devices and provide high quality Internet access at schools. This paper investigates four months worth of continuous measurements conducted by an ESP using a largescale, passive, in-device Quality of Experience (QoE) monitoring system deployed into a nationwide network of education-purpose devices. These measurements cover more than 800 education centers and about 4000 devices, used both in schools and at home. Using this rich dataset, we present an exhaustive characterization of the browsing behavior, and a quantification of the web and video QoE in this educational context. Web QoE results showed a better performance for school Wi-Fi networks compared to home connections, suggesting that several issues may arise for ESPs due to the increasing relevance of home-schooling caused by the COVID-19 pandemic.
• Discrete-time Analysis of Multicomponent GI/GI/1 Queueing Networks Geissler, Stefan; Lange, Stanislav; Tran-Gia, Phuoc; Hoßfeld, Tobias in Conference on Networked Systems (NetSys) (2021).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  In this work, we provide initial insights regarding the error introduced into multicomponent queueing systems by assuming the departure processes of arbitrary GI/GI/1-∞ queues to be renewal processes. To this end, we compute the sojourn time distribution as well as departure distributions of a linear chain of queueing components and compare the results to a simulation of the same system. By applying the renewal approximation, potential autocorrelations of the departure processes are lost. We investigate the magnitude of this error regarding both the sojourn time as well as interdeparture time distributions for a broad set of parameters. Although more indepth studies are needed, our results show that both distributions can be closely approximated, which allows the application of the model to asses the performance of real world NFV function chains.

  @inproceedings{info3-inproceedings-2021-4, abstract = {In this work, we provide initial insights regarding the error introduced into multicomponent queueing systems by assuming the departure processes of arbitrary GI/GI/1-∞ queues to be renewal processes. To this end, we compute the sojourn time distribution as well as departure distributions of a linear chain of queueing components and compare the results to a simulation of the same system. By applying the renewal approximation, potential autocorrelations of the departure processes are lost. We investigate the magnitude of this error regarding both the sojourn time as well as interdeparture time distributions for a broad set of parameters. Although more indepth studies are needed, our results show that both distributions can be closely approximated, which allows the application of the model to asses the performance of real world NFV function chains.}, author = {Geissler, Stefan and Lange, Stanislav and Tran-Gia, Phuoc and Hoßfeld, Tobias}, booktitle = {Conference on Networked Systems (NetSys)}, keywords = {sys:hidden:inproceedings}, month = 11, title = {Discrete-time Analysis of Multicomponent GI/GI/1 Queueing Networks}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-4 %A Geissler, Stefan %A Lange, Stanislav %A Tran-Gia, Phuoc %A Hoßfeld, Tobias %B Conference on Networked Systems (NetSys) %D 2021 %T Discrete-time Analysis of Multicomponent GI/GI/1 Queueing Networks %X In this work, we provide initial insights regarding the error introduced into multicomponent queueing systems by assuming the departure processes of arbitrary GI/GI/1-∞ queues to be renewal processes. To this end, we compute the sojourn time distribution as well as departure distributions of a linear chain of queueing components and compare the results to a simulation of the same system. By applying the renewal approximation, potential autocorrelations of the departure processes are lost. We investigate the magnitude of this error regarding both the sojourn time as well as interdeparture time distributions for a broad set of parameters. Although more indepth studies are needed, our results show that both distributions can be closely approximated, which allows the application of the model to asses the performance of real world NFV function chains.
• ML-Assisted Latency Assignments in Time-Sensitive Networking Grigorjew, Alexej; Seufert, Michael; Wehner, Nikolas; Hofmann, Jan; Hoßfeld, Tobias in IFIP/IEEE International Symposium on Integrated Network Management (IM 2021) (2021).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Recent developments in industrial automation and invehicle communication have raised the requirements of real-time networking. Bus systems that were traditionally deployed in these fields cannot provide sufficient bandwidth and are now shifting towards Ethernet for their real-time communication needs. In this field, standardization efforts from the IEEE and the IETF have developed new data plane mechanisms such as shapers and schedulers, as well as control plane mechanisms such as reservation protocols to support their new requirements. However, their implementation and their optimal configuration remain an important factor for their efficiency. This work presents a machine learning framework that takes on the configuration task. Four different models are trained for the configuration of per-hop latency guarantees in a distributed resource reservation process and compared with respect to their real-time traffic capacity. The evaluation shows that all models provide good configurations for the provided scenarios, but more importantly, they represent a first step for a semi-automated configuration of parameters in Time-Sensitive Networking.

  @inproceedings{info3-inproceedings-2021-2, abstract = {Recent developments in industrial automation and invehicle communication have raised the requirements of real-time networking. Bus systems that were traditionally deployed in these fields cannot provide sufficient bandwidth and are now shifting towards Ethernet for their real-time communication needs. In this field, standardization efforts from the IEEE and the IETF have developed new data plane mechanisms such as shapers and schedulers, as well as control plane mechanisms such as reservation protocols to support their new requirements. However, their implementation and their optimal configuration remain an important factor for their efficiency. This work presents a machine learning framework that takes on the configuration task. Four different models are trained for the configuration of per-hop latency guarantees in a distributed resource reservation process and compared with respect to their real-time traffic capacity. The evaluation shows that all models provide good configurations for the provided scenarios, but more importantly, they represent a first step for a semi-automated configuration of parameters in Time-Sensitive Networking.}, address = {Bordeaux, France (Virtual Conference)}, author = {Grigorjew, Alexej and Seufert, Michael and Wehner, Nikolas and Hofmann, Jan and Hoßfeld, Tobias}, booktitle = {IFIP/IEEE International Symposium on Integrated Network Management (IM 2021)}, keywords = {kikdin}, month = 5, title = {ML-Assisted Latency Assignments in Time-Sensitive Networking}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-2 %A Grigorjew, Alexej %A Seufert, Michael %A Wehner, Nikolas %A Hofmann, Jan %A Hoßfeld, Tobias %B IFIP/IEEE International Symposium on Integrated Network Management (IM 2021) %C Bordeaux, France (Virtual Conference) %D 2021 %T ML-Assisted Latency Assignments in Time-Sensitive Networking %X Recent developments in industrial automation and invehicle communication have raised the requirements of real-time networking. Bus systems that were traditionally deployed in these fields cannot provide sufficient bandwidth and are now shifting towards Ethernet for their real-time communication needs. In this field, standardization efforts from the IEEE and the IETF have developed new data plane mechanisms such as shapers and schedulers, as well as control plane mechanisms such as reservation protocols to support their new requirements. However, their implementation and their optimal configuration remain an important factor for their efficiency. This work presents a machine learning framework that takes on the configuration task. Four different models are trained for the configuration of per-hop latency guarantees in a distributed resource reservation process and compared with respect to their real-time traffic capacity. The evaluation shows that all models provide good configurations for the provided scenarios, but more importantly, they represent a first step for a semi-automated configuration of parameters in Time-Sensitive Networking.
• Distributed Implementation of Deterministic Networking in Existing Non-TSN Ethernet Switches Grigorjew, Alexej; Baier, Christian; Metzger, Florian; Hoßfeld, Tobias in Workshop on Time-sensitive and Deterministic Networking (TsDN) (2021).
  • [ Abstract ]
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  • [ EndNote ]
  Deterministic networking is quickly gaining importance, as several domains previously dominated by bus systems are now switching to Ethernet. While standardization efforts, especially from the Time-Sensitive Networking (TSN) group, are ongoing, practical deployments are still far off until configuration guidelines and resource management are able to use these tools to their full potential. As an alternative, this work presents a working implementation of bounded latency with an off-the-shelf non-TSN Ethernet switch. The solution is based on a distributed reservation protocol and admission control. It proves that bounded latency is already possible with simple priority-based transmission, and it provides valuable insights for the development and operation of future real-time networking solutions.

  @inproceedings{info3-inproceedings-2021-6, abstract = {Deterministic networking is quickly gaining importance, as several domains previously dominated by bus systems are now switching to Ethernet. While standardization efforts, especially from the Time-Sensitive Networking (TSN) group, are ongoing, practical deployments are still far off until configuration guidelines and resource management are able to use these tools to their full potential. As an alternative, this work presents a working implementation of bounded latency with an off-the-shelf non-TSN Ethernet switch. The solution is based on a distributed reservation protocol and admission control. It proves that bounded latency is already possible with simple priority-based transmission, and it provides valuable insights for the development and operation of future real-time networking solutions.}, author = {Grigorjew, Alexej and Baier, Christian and Metzger, Florian and Hoßfeld, Tobias}, booktitle = {Workshop on Time-sensitive and Deterministic Networking (TsDN)}, keywords = {ngn}, month = 6, title = {Distributed Implementation of Deterministic Networking in Existing Non-TSN Ethernet Switches}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-6 %A Grigorjew, Alexej %A Baier, Christian %A Metzger, Florian %A Hoßfeld, Tobias %B Workshop on Time-sensitive and Deterministic Networking (TsDN) %D 2021 %T Distributed Implementation of Deterministic Networking in Existing Non-TSN Ethernet Switches %X Deterministic networking is quickly gaining importance, as several domains previously dominated by bus systems are now switching to Ethernet. While standardization efforts, especially from the Time-Sensitive Networking (TSN) group, are ongoing, practical deployments are still far off until configuration guidelines and resource management are able to use these tools to their full potential. As an alternative, this work presents a working implementation of bounded latency with an off-the-shelf non-TSN Ethernet switch. The solution is based on a distributed reservation protocol and admission control. It proves that bounded latency is already possible with simple priority-based transmission, and it provides valuable insights for the development and operation of future real-time networking solutions.
• Dynamic Real-Time Stream Reservation with TAS and Shared Time Windows Grigorjew, Alexej; Gray, Nicholas; Hoßfeld, Tobias in 2nd International Workshop on Time-Sensitive and Deterministic Networking (TENSOR) (2021).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Motivated by new use cases such as industrial automation and in-vehicle communication, Time-Sensitive Networking is further improving the layer~2 standards for real-time communication in Ethernet networks. As periodic traffic is a common requirement in such scenarios, the Time Aware Shaper (TAS) is a highly popular mechanism that allows the realization of real-time guarantees in synchronized networks. Most applications in literature suggest to configure the TAS for full stream isolation such that the lowest delays can be achieved. However, this ``zero-queuing'' strategy requires a high amount of computational resources and time, as the configuration of the gate control lists of each port is a complex task, which is not suitable for scenarios with dynamically changing requirements. This paper presents a novel approach with shared time windows. In combination with stream reservation techniques that are commonly applied for asynchronous mechanisms, the network is able to accept new streams during operation without complex reconfiguration, while still benefiting from some degree of isolation compared to conventional asynchronous shapers. The evaluation shows that, given the right circumstances, the number of accepted real-time streams can be improved significantly.

  @inproceedings{info3-inproceedings-2021-7, abstract = {Motivated by new use cases such as industrial automation and in-vehicle communication, Time-Sensitive Networking is further improving the layer 2 standards for real-time communication in Ethernet networks. As periodic traffic is a common requirement in such scenarios, the Time Aware Shaper (TAS) is a highly popular mechanism that allows the realization of real-time guarantees in synchronized networks. Most applications in literature suggest to configure the TAS for full stream isolation such that the lowest delays can be achieved. However, this ``zero-queuing'' strategy requires a high amount of computational resources and time, as the configuration of the gate control lists of each port is a complex task, which is not suitable for scenarios with dynamically changing requirements. This paper presents a novel approach with shared time windows. In combination with stream reservation techniques that are commonly applied for asynchronous mechanisms, the network is able to accept new streams during operation without complex reconfiguration, while still benefiting from some degree of isolation compared to conventional asynchronous shapers. The evaluation shows that, given the right circumstances, the number of accepted real-time streams can be improved significantly.}, author = {Grigorjew, Alexej and Gray, Nicholas and Hoßfeld, Tobias}, booktitle = {2nd International Workshop on Time-Sensitive and Deterministic Networking (TENSOR)}, keywords = {ngn}, month = 6, title = {Dynamic Real-Time Stream Reservation with TAS and Shared Time Windows}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-7 %A Grigorjew, Alexej %A Gray, Nicholas %A Hoßfeld, Tobias %B 2nd International Workshop on Time-Sensitive and Deterministic Networking (TENSOR) %D 2021 %T Dynamic Real-Time Stream Reservation with TAS and Shared Time Windows %X Motivated by new use cases such as industrial automation and in-vehicle communication, Time-Sensitive Networking is further improving the layer~2 standards for real-time communication in Ethernet networks. As periodic traffic is a common requirement in such scenarios, the Time Aware Shaper (TAS) is a highly popular mechanism that allows the realization of real-time guarantees in synchronized networks. Most applications in literature suggest to configure the TAS for full stream isolation such that the lowest delays can be achieved. However, this ``zero-queuing'' strategy requires a high amount of computational resources and time, as the configuration of the gate control lists of each port is a complex task, which is not suitable for scenarios with dynamically changing requirements. This paper presents a novel approach with shared time windows. In combination with stream reservation techniques that are commonly applied for asynchronous mechanisms, the network is able to accept new streams during operation without complex reconfiguration, while still benefiting from some degree of isolation compared to conventional asynchronous shapers. The evaluation shows that, given the right circumstances, the number of accepted real-time streams can be improved significantly.
• Improving LoRaWAN’s Successful Information Transmission Rate with Redundancy Loh, Frank; Raffeck, Simon; Metzger, Florian; Hoßfeld, Tobias in 17th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob) (2021).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
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  The adaptation of Internet of Things in our everyday life shows different new demands and challenges. One of the fastest growing technologies in this context are Low Power Wide Area Networks with LoRaWAN as one of their most prominent representatives. The promise of this technology is to transmit sensor data over large distances with very little energy consumption. But transmission behavior, and especially overhead and collision probability, must be studied in detail to improve transmission quality and energy consumption due to the random access nature of LoRaWAN. Because of that, this work investigates the LoRaWAN channel capacity by analyzing the transmission overhead, the collision probability, and the data loss. At the end, an energy consumption comparison is done. The contribution is a novel approach based on aggregation and retransmission that shows a decreased data loss of up to 20% compared to the currently used random channel access.

  @inproceedings{info3-inproceedings-2021-19, abstract = {The adaptation of Internet of Things in our everyday life shows different new demands and challenges. One of the fastest growing technologies in this context are Low Power Wide Area Networks with LoRaWAN as one of their most prominent representatives. The promise of this technology is to transmit sensor data over large distances with very little energy consumption. But transmission behavior, and especially overhead and collision probability, must be studied in detail to improve transmission quality and energy consumption due to the random access nature of LoRaWAN. Because of that, this work investigates the LoRaWAN channel capacity by analyzing the transmission overhead, the collision probability, and the data loss. At the end, an energy consumption comparison is done. The contribution is a novel approach based on aggregation and retransmission that shows a decreased data loss of up to 20% compared to the currently used random channel access.}, author = {Loh, Frank and Raffeck, Simon and Metzger, Florian and Hoßfeld, Tobias}, booktitle = {17th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)}, keywords = {5mart}, month = 10, title = {Improving LoRaWAN’s Successful Information Transmission Rate with Redundancy}, year = 2021 }

  %0 Conference Paper %1 info3-inproceedings-2021-19 %A Loh, Frank %A Raffeck, Simon %A Metzger, Florian %A Hoßfeld, Tobias %B 17th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob) %D 2021 %T Improving LoRaWAN’s Successful Information Transmission Rate with Redundancy %X The adaptation of Internet of Things in our everyday life shows different new demands and challenges. One of the fastest growing technologies in this context are Low Power Wide Area Networks with LoRaWAN as one of their most prominent representatives. The promise of this technology is to transmit sensor data over large distances with very little energy consumption. But transmission behavior, and especially overhead and collision probability, must be studied in detail to improve transmission quality and energy consumption due to the random access nature of LoRaWAN. Because of that, this work investigates the LoRaWAN channel capacity by analyzing the transmission overhead, the collision probability, and the data loss. At the end, an energy consumption comparison is done. The contribution is a novel approach based on aggregation and retransmission that shows a decreased data loss of up to 20% compared to the currently used random channel access.

• From QoS Distributions to QoE Distributions: a System’s Perspective Hoßfeld, Tobias; Heegaard, Poul E.; Varela, Martin; Skorin-Kapov, Lea; Fiedler, Markus in 4th International Workshop on Quality of Experience Management (QoE Management 2020), featured by IEEE Conference on Network Softwarization (IEEE NetSoft 2020) (2020).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  • [ Download ]
  In the context of QoE management, network and service providers commonly rely on models that map system QoS conditions (e.g., system response time, packet loss, etc.) to estimated end user QoE values. Observable QoS conditions in the system may be assumed to follow a certain distribution, meaning that different end users will experience different conditions. On the other hand, drawing from the results of subjective user studies, we know that user diversity leads to distributions of user scores for any given test conditions (in this case referring to the QoS parameters of interest). Our previous studies have shown that to correctly derive various QoE metrics (e.g., Mean Opinion Score (MOS), quantiles, probability of users rating 'good or better', etc.) in a system under given conditions, there is a need to consider rating distributions obtained from user studies, which are often times not available. In the paper we extend these findings to show how to approximate user rating distributions given a QoS-to-MOS mapping function and second order statistics. Such a user rating distribution may then be combined with a QoS distribution observed in a system to finally derive corresponding distributions of QoE scores. Scripts are provided for the approximating a QoE distribution with a Beta distribution for given MOS and SOS parameter at https://github.com/hossfeld/approx-qoe-distribution.

  @inproceedings{info3-inproceedings-2020-6, abstract = {In the context of QoE management, network and service providers commonly rely on models that map system QoS conditions (e.g., system response time, packet loss, etc.) to estimated end user QoE values. Observable QoS conditions in the system may be assumed to follow a certain distribution, meaning that different end users will experience different conditions. On the other hand, drawing from the results of subjective user studies, we know that user diversity leads to distributions of user scores for any given test conditions (in this case referring to the QoS parameters of interest). Our previous studies have shown that to correctly derive various QoE metrics (e.g., Mean Opinion Score (MOS), quantiles, probability of users rating 'good or better', etc.) in a system under given conditions, there is a need to consider rating distributions obtained from user studies, which are often times not available. In the paper we extend these findings to show how to approximate user rating distributions given a QoS-to-MOS mapping function and second order statistics. Such a user rating distribution may then be combined with a QoS distribution observed in a system to finally derive corresponding distributions of QoE scores. Scripts are provided for the approximating a QoE distribution with a Beta distribution for given MOS and SOS parameter at https://github.com/hossfeld/approx-qoe-distribution.}, address = {Ghent, Belgium}, author = {Hoßfeld, Tobias and Heegaard, Poul E. and Varela, Martin and Skorin-Kapov, Lea and Fiedler, Markus}, booktitle = {4th International Workshop on Quality of Experience Management (QoE Management 2020), featured by IEEE Conference on Network Softwarization (IEEE NetSoft 2020)}, keywords = {sys:hidden:inproceedings}, month = 7, title = {From QoS Distributions to QoE Distributions: a System's Perspective}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-6 %A Hoßfeld, Tobias %A Heegaard, Poul E. %A Varela, Martin %A Skorin-Kapov, Lea %A Fiedler, Markus %B 4th International Workshop on Quality of Experience Management (QoE Management 2020), featured by IEEE Conference on Network Softwarization (IEEE NetSoft 2020) %C Ghent, Belgium %D 2020 %T From QoS Distributions to QoE Distributions: a System's Perspective %X In the context of QoE management, network and service providers commonly rely on models that map system QoS conditions (e.g., system response time, packet loss, etc.) to estimated end user QoE values. Observable QoS conditions in the system may be assumed to follow a certain distribution, meaning that different end users will experience different conditions. On the other hand, drawing from the results of subjective user studies, we know that user diversity leads to distributions of user scores for any given test conditions (in this case referring to the QoS parameters of interest). Our previous studies have shown that to correctly derive various QoE metrics (e.g., Mean Opinion Score (MOS), quantiles, probability of users rating 'good or better', etc.) in a system under given conditions, there is a need to consider rating distributions obtained from user studies, which are often times not available. In the paper we extend these findings to show how to approximate user rating distributions given a QoS-to-MOS mapping function and second order statistics. Such a user rating distribution may then be combined with a QoS distribution observed in a system to finally derive corresponding distributions of QoE scores. Scripts are provided for the approximating a QoE distribution with a Beta distribution for given MOS and SOS parameter at https://github.com/hossfeld/approx-qoe-distribution.
• Personal Task Design Preferences of Crowdworkers Hirth, Matthias; Borchert, Kathrin; de Moor, Katrien; Borst, Vanessa; Hoßfeld, Tobias in 12th International Conference on Quality of Multimedia Experience (QoMEX) (2020).
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  • [ EndNote ]
  @inproceedings{info3-inproceedings-2020-5, address = {Athlone, Ireland}, author = {Hirth, Matthias and Borchert, Kathrin and de Moor, Katrien and Borst, Vanessa and Hoßfeld, Tobias}, booktitle = {12th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ua-net}, month = 5, title = {Personal Task Design Preferences of Crowdworkers}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-5 %A Hirth, Matthias %A Borchert, Kathrin %A de Moor, Katrien %A Borst, Vanessa %A Hoßfeld, Tobias %B 12th International Conference on Quality of Multimedia Experience (QoMEX) %C Athlone, Ireland %D 2020 %T Personal Task Design Preferences of Crowdworkers
• Different Points of View: Impact of 3D Point Cloud Reduction on QoE of Rendered Images Seufert, Michael; Kargl, Julian; Schauer, Johannes; Nüchter, Andreas; Hoßfeld, Tobias in 12th International Conference on Quality of Multimedia Experience (QoMEX) (2020).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Modern photogrammetric methods as well as laser measurement systems make it easy to collect large 3D point clouds that sample objects or environments. As the recorded point clouds can be used to render computer-generated images and models, they are of particular interest in the domains of geographical and architectural engineering, as well for computer graphics (e.g., games or virtual reality). However, point clouds have a huge storage demand, thus, point clouds shall be reduced by removing some of the points. This will inevitably also reduce the Quality of Experience (QoE) of media, which is rendered from the reduced point clouds. In this work, the impact of two different reduction methods on the QoE of rendered images is investigated from two point of views, i.e., based on ratings from both naive crowdworkers as well as point cloud experts.

  @inproceedings{info3-inproceedings-2020-4, abstract = {Modern photogrammetric methods as well as laser measurement systems make it easy to collect large 3D point clouds that sample objects or environments. As the recorded point clouds can be used to render computer-generated images and models, they are of particular interest in the domains of geographical and architectural engineering, as well for computer graphics (e.g., games or virtual reality). However, point clouds have a huge storage demand, thus, point clouds shall be reduced by removing some of the points. This will inevitably also reduce the Quality of Experience (QoE) of media, which is rendered from the reduced point clouds. In this work, the impact of two different reduction methods on the QoE of rendered images is investigated from two point of views, i.e., based on ratings from both naive crowdworkers as well as point cloud experts.}, address = {Athlone, Ireland}, author = {Seufert, Michael and Kargl, Julian and Schauer, Johannes and Nüchter, Andreas and Hoßfeld, Tobias}, booktitle = {12th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ua-net}, month = 5, title = {Different Points of View: Impact of 3D Point Cloud Reduction on QoE of Rendered Images}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-4 %A Seufert, Michael %A Kargl, Julian %A Schauer, Johannes %A Nüchter, Andreas %A Hoßfeld, Tobias %B 12th International Conference on Quality of Multimedia Experience (QoMEX) %C Athlone, Ireland %D 2020 %T Different Points of View: Impact of 3D Point Cloud Reduction on QoE of Rendered Images %X Modern photogrammetric methods as well as laser measurement systems make it easy to collect large 3D point clouds that sample objects or environments. As the recorded point clouds can be used to render computer-generated images and models, they are of particular interest in the domains of geographical and architectural engineering, as well for computer graphics (e.g., games or virtual reality). However, point clouds have a huge storage demand, thus, point clouds shall be reduced by removing some of the points. This will inevitably also reduce the Quality of Experience (QoE) of media, which is rendered from the reduced point clouds. In this work, the impact of two different reduction methods on the QoE of rendered images is investigated from two point of views, i.e., based on ratings from both naive crowdworkers as well as point cloud experts.
• Optimizing HAS for 360-Degree Videos Moldovan, Christian; Loh, Frank; Seufert, Michael; Hoßfeld, Tobias in 5th IEEE/IFIP International Workshop on Analytics for Network and Service Management (AnNet) (2020).
  • [ BibTeX ]
  • [ EndNote ]
  @inproceedings{info3-inproceedings-2020-1, address = {Budapest, Hungary}, author = {Moldovan, Christian and Loh, Frank and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {5th IEEE/IFIP International Workshop on Analytics for Network and Service Management (AnNet)}, keywords = {net-man}, month = 4, title = {Optimizing HAS for 360-Degree Videos}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-1 %A Moldovan, Christian %A Loh, Frank %A Seufert, Michael %A Hoßfeld, Tobias %B 5th IEEE/IFIP International Workshop on Analytics for Network and Service Management (AnNet) %C Budapest, Hungary %D 2020 %T Optimizing HAS for 360-Degree Videos
• QoE Assessment of Enterprise Applications based on Self-motivated Ratings Borchert, Kathrin; Seufert, Michael; Hildebrand, Kathrin; Hoßfeld, Tobias in 12th International Conference on Quality of Multimedia Experience (QoMEX) (2020).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  In most companies, enterprise applications, such as office products or databases, are heavily used by employees during work hours. Impairments and performance issues not only slow down business processes, but might also increase the frustration of the workforce. While Quality of Experience (QoE) has been widely studied for personal multimedia applications, such as video streaming, its application to the business usage domain is still in its infancy. Due to several reasons, e.g., the high complexity of IT infrastructure, classical QoE studies can hardly be transferred to business applications. These studies are often independent from the context of usage and actively poll ratings from their participants. This work contrasts the commonly used "pull" method for collecting user ratings with a self-motivated "push" approach. This approach is inspired by complaint systems, in which users can directly report problems with a technical system as soon as they notice them. Therefore, performance assessments of a business application from employees of a cooperating company are collected with both rating systems during a time span of 1.5 years. Besides the analysis of the interaction of users with the "push" system, differences between the two methods are discussed. Further, QoE models for the monitored business application are derived based on the self-motivated "push" ratings.

  @inproceedings{info3-inproceedings-2020-3, abstract = {In most companies, enterprise applications, such as office products or databases, are heavily used by employees during work hours. Impairments and performance issues not only slow down business processes, but might also increase the frustration of the workforce. While Quality of Experience (QoE) has been widely studied for personal multimedia applications, such as video streaming, its application to the business usage domain is still in its infancy. Due to several reasons, e.g., the high complexity of IT infrastructure, classical QoE studies can hardly be transferred to business applications. These studies are often independent from the context of usage and actively poll ratings from their participants. This work contrasts the commonly used "pull" method for collecting user ratings with a self-motivated "push" approach. This approach is inspired by complaint systems, in which users can directly report problems with a technical system as soon as they notice them. Therefore, performance assessments of a business application from employees of a cooperating company are collected with both rating systems during a time span of 1.5 years. Besides the analysis of the interaction of users with the "push" system, differences between the two methods are discussed. Further, QoE models for the monitored business application are derived based on the self-motivated "push" ratings.}, address = {Athlone, Ireland}, author = {Borchert, Kathrin and Seufert, Michael and Hildebrand, Kathrin and Hoßfeld, Tobias}, booktitle = {12th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ua-net}, month = 5, title = {QoE Assessment of Enterprise Applications based on Self-motivated Ratings}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-3 %A Borchert, Kathrin %A Seufert, Michael %A Hildebrand, Kathrin %A Hoßfeld, Tobias %B 12th International Conference on Quality of Multimedia Experience (QoMEX) %C Athlone, Ireland %D 2020 %T QoE Assessment of Enterprise Applications based on Self-motivated Ratings %X In most companies, enterprise applications, such as office products or databases, are heavily used by employees during work hours. Impairments and performance issues not only slow down business processes, but might also increase the frustration of the workforce. While Quality of Experience (QoE) has been widely studied for personal multimedia applications, such as video streaming, its application to the business usage domain is still in its infancy. Due to several reasons, e.g., the high complexity of IT infrastructure, classical QoE studies can hardly be transferred to business applications. These studies are often independent from the context of usage and actively poll ratings from their participants. This work contrasts the commonly used "pull" method for collecting user ratings with a self-motivated "push" approach. This approach is inspired by complaint systems, in which users can directly report problems with a technical system as soon as they notice them. Therefore, performance assessments of a business application from employees of a cooperating company are collected with both rating systems during a time span of 1.5 years. Besides the analysis of the interaction of users with the "push" system, differences between the two methods are discussed. Further, QoE models for the monitored business application are derived based on the self-motivated "push" ratings.
• Is the Uplink Enough? Estimating Video Stalls from Encrypted Network Traffic Loh, Frank; Wamser, Florian; Moldovan, Christian; Zeidler, Bernd; Tsilimantos, Dimitrios; Valentin, Stefan; Hoßfeld, Tobias in 32th IEEE/IFIP Network Operations and Management Symposium (2020).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  • [ Download ]
  Today’s traffic projections speak of almost 58 % video traffic across the Internet. Nearly all video traffic is encrypted, accounting for more than 50 % encrypted traffic worldwide. To analyze video traffic today, or even estimate its quality in the network, a deep look into the traffic characteristics has to be done. But then, important quality metrics from the traffic behavior can be derived. Based on extensive measurements we show in this work how to measure and estimate video stalls for mobile adaptive streaming. The underlying dataset includes more than 900 hours of video footage from the native YouTube app, measured over 18 different videos in 56 network scenarios in two cities in Europe. We outline a possible approach to estimate the video playback buffer size based on uplink video chunk requests in real-time to break down the video stalls. This work is intended as a tool for network operators to receive further knowledge of the characteristics of video streaming traffic to quantify the most important QoE degradation factors of one of the most important applications today.

  @inproceedings{info3-inproceedings-2020-2, abstract = {Today’s traffic projections speak of almost 58 % video traffic across the Internet. Nearly all video traffic is encrypted, accounting for more than 50 % encrypted traffic worldwide. To analyze video traffic today, or even estimate its quality in the network, a deep look into the traffic characteristics has to be done. But then, important quality metrics from the traffic behavior can be derived. Based on extensive measurements we show in this work how to measure and estimate video stalls for mobile adaptive streaming. The underlying dataset includes more than 900 hours of video footage from the native YouTube app, measured over 18 different videos in 56 network scenarios in two cities in Europe. We outline a possible approach to estimate the video playback buffer size based on uplink video chunk requests in real-time to break down the video stalls. This work is intended as a tool for network operators to receive further knowledge of the characteristics of video streaming traffic to quantify the most important QoE degradation factors of one of the most important applications today.}, address = {Budapest, Hungary}, author = {Loh, Frank and Wamser, Florian and Moldovan, Christian and Zeidler, Bernd and Tsilimantos, Dimitrios and Valentin, Stefan and Hoßfeld, Tobias}, booktitle = {32th IEEE/IFIP Network Operations and Management Symposium}, keywords = {can}, month = 4, title = {Is the Uplink Enough? Estimating Video Stalls from Encrypted Network Traffic}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-2 %A Loh, Frank %A Wamser, Florian %A Moldovan, Christian %A Zeidler, Bernd %A Tsilimantos, Dimitrios %A Valentin, Stefan %A Hoßfeld, Tobias %B 32th IEEE/IFIP Network Operations and Management Symposium %C Budapest, Hungary %D 2020 %T Is the Uplink Enough? Estimating Video Stalls from Encrypted Network Traffic %X Today’s traffic projections speak of almost 58 % video traffic across the Internet. Nearly all video traffic is encrypted, accounting for more than 50 % encrypted traffic worldwide. To analyze video traffic today, or even estimate its quality in the network, a deep look into the traffic characteristics has to be done. But then, important quality metrics from the traffic behavior can be derived. Based on extensive measurements we show in this work how to measure and estimate video stalls for mobile adaptive streaming. The underlying dataset includes more than 900 hours of video footage from the native YouTube app, measured over 18 different videos in 56 network scenarios in two cities in Europe. We outline a possible approach to estimate the video playback buffer size based on uplink video chunk requests in real-time to break down the video stalls. This work is intended as a tool for network operators to receive further knowledge of the characteristics of video streaming traffic to quantify the most important QoE degradation factors of one of the most important applications today.
• Scoring High: Analysis and Prediction of Viewer Behavior and Engagement in the Context of 2018 FIFA WC Live Streaming Wehner, Nikolas; Seufert, Michael; Egger-Lampl, Sebastian; Gardlo, Bruno; Casas, Pedro; Schatz, Raimund in Proceedings of the 28th ACM International Conference on Multimedia (MM) (2020).
  • [ BibTeX ]
  • [ EndNote ]
  @inproceedings{info3-inproceedings-2020-9, address = {Seattle, WA, USA}, author = {Wehner, Nikolas and Seufert, Michael and Egger-Lampl, Sebastian and Gardlo, Bruno and Casas, Pedro and Schatz, Raimund}, booktitle = {Proceedings of the 28th ACM International Conference on Multimedia (MM)}, keywords = {ucn}, month = 10, title = {Scoring High: Analysis and Prediction of Viewer Behavior and Engagement in the Context of 2018 FIFA WC Live Streaming}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-9 %A Wehner, Nikolas %A Seufert, Michael %A Egger-Lampl, Sebastian %A Gardlo, Bruno %A Casas, Pedro %A Schatz, Raimund %B Proceedings of the 28th ACM International Conference on Multimedia (MM) %C Seattle, WA, USA %D 2020 %T Scoring High: Analysis and Prediction of Viewer Behavior and Engagement in the Context of 2018 FIFA WC Live Streaming
• Studying the Impact of the Content Selection Method on the Video QoE on Mobile Devices Wehner, Nikolas; Mertinat, Nils; Seufert, Michael; Hoßfeld, Tobias in 12th International Conference on Quality of Multimedia Experience (QoMEX) (2020).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  When conducting video QoE studies, participants are usually asked to rate the QoE of prepared test videos. However, participants are given no choice to select content, which they like or in which they are interested. This may cause annoyance or frustration when conducting the QoE study, which eventually might affect the QoE results of the study. The consequent question is whether the content liking has a direct impact on the submitted ratings by the participants and whether the freedom of choosing the video content in QoE studies results in better ratings. To investigate this research question, MCA, an existing framework for crowdsourced video testing, is extended and used in a pilot field study. MCA runs on mobile devices and allows users to watch the tested conditions of a QoE study within video content of their interest. The results of a QoE study with individual and dynamic content selection are compared to a QoE study with pre-selected contents. Moreover, this work includes a comparison to a previous QoE study for validation. As the previous study was conducted on desktop PCs, the MCA study further allows to identify differences in the stalling perception between studies on desktop PCs and mobile devices.

  @inproceedings{info3-inproceedings-2020-8, abstract = {When conducting video QoE studies, participants are usually asked to rate the QoE of prepared test videos. However, participants are given no choice to select content, which they like or in which they are interested. This may cause annoyance or frustration when conducting the QoE study, which eventually might affect the QoE results of the study. The consequent question is whether the content liking has a direct impact on the submitted ratings by the participants and whether the freedom of choosing the video content in QoE studies results in better ratings. To investigate this research question, MCA, an existing framework for crowdsourced video testing, is extended and used in a pilot field study. MCA runs on mobile devices and allows users to watch the tested conditions of a QoE study within video content of their interest. The results of a QoE study with individual and dynamic content selection are compared to a QoE study with pre-selected contents. Moreover, this work includes a comparison to a previous QoE study for validation. As the previous study was conducted on desktop PCs, the MCA study further allows to identify differences in the stalling perception between studies on desktop PCs and mobile devices.}, address = {Athlone, Ireland}, author = {Wehner, Nikolas and Mertinat, Nils and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {12th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ucn}, month = 5, title = {Studying the Impact of the Content Selection Method on the Video QoE on Mobile Devices}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-8 %A Wehner, Nikolas %A Mertinat, Nils %A Seufert, Michael %A Hoßfeld, Tobias %B 12th International Conference on Quality of Multimedia Experience (QoMEX) %C Athlone, Ireland %D 2020 %T Studying the Impact of the Content Selection Method on the Video QoE on Mobile Devices %X When conducting video QoE studies, participants are usually asked to rate the QoE of prepared test videos. However, participants are given no choice to select content, which they like or in which they are interested. This may cause annoyance or frustration when conducting the QoE study, which eventually might affect the QoE results of the study. The consequent question is whether the content liking has a direct impact on the submitted ratings by the participants and whether the freedom of choosing the video content in QoE studies results in better ratings. To investigate this research question, MCA, an existing framework for crowdsourced video testing, is extended and used in a pilot field study. MCA runs on mobile devices and allows users to watch the tested conditions of a QoE study within video content of their interest. The results of a QoE study with individual and dynamic content selection are compared to a QoE study with pre-selected contents. Moreover, this work includes a comparison to a previous QoE study for validation. As the previous study was conducted on desktop PCs, the MCA study further allows to identify differences in the stalling perception between studies on desktop PCs and mobile devices.
• Don’t Stop the Music: Crowdsourced QoE Assessment of Music Streaming with Stalling Schwind, Anika; Moldovan, Christian; Janiak, Tim; Dworschak, Nemo-Dario; Hoßfeld, Tobias in 12th International Conference on Quality of Multimedia Experience (QoMEX) (2020).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Streaming made a lasting effect on the way our society consumes media in the last decade. While due to streaming the way we listen to music and podcasts has changed drastically, there are very few studies about its Quality of Experience (QoE) and possible influence factors. From video QoE studies, we know that, for example, undesirable stops of the stream (stalling events) have a significant impact on QoE. However, the way in which music and video streaming is consumed differs significantly, as music is often played in the background, and thus, the influence of stalling could be significantly different. Thus, this work evaluates the impact of stalling on music streaming QoE. Therefore, we conduct two crowdsourced user studies: In the first study, users have to rate four songs with different stalling patterns and evaluate the degree of impairments. Afterwards, we compare the ratings to the results of a lab study and show that they are highly correlated, and that crowdsourcing is a suitable way of measuring music streaming QoE. In addition, we conduct a second crowdsourcing study to investigate the influence of the user's attentiveness on QoE. Here, participants have to listen to one song with two stalling events, while one half of them had to transcribe a handwritten text with music playing in the background. The attentiveness shows no influence on the perceived streaming quality, but it shows a significant influence on the perceived quality degradation due to stalling events. Furthermore, considerably more stalling events were missed for workers who focused on the transcription. These results are an important step towards establishing new methods for investigating QoE in multimedia.

  @inproceedings{info3-inproceedings-2020-7, abstract = {Streaming made a lasting effect on the way our society consumes media in the last decade. While due to streaming the way we listen to music and podcasts has changed drastically, there are very few studies about its Quality of Experience (QoE) and possible influence factors. From video QoE studies, we know that, for example, undesirable stops of the stream (stalling events) have a significant impact on QoE. However, the way in which music and video streaming is consumed differs significantly, as music is often played in the background, and thus, the influence of stalling could be significantly different. Thus, this work evaluates the impact of stalling on music streaming QoE. Therefore, we conduct two crowdsourced user studies: In the first study, users have to rate four songs with different stalling patterns and evaluate the degree of impairments. Afterwards, we compare the ratings to the results of a lab study and show that they are highly correlated, and that crowdsourcing is a suitable way of measuring music streaming QoE. In addition, we conduct a second crowdsourcing study to investigate the influence of the user's attentiveness on QoE. Here, participants have to listen to one song with two stalling events, while one half of them had to transcribe a handwritten text with music playing in the background. The attentiveness shows no influence on the perceived streaming quality, but it shows a significant influence on the perceived quality degradation due to stalling events. Furthermore, considerably more stalling events were missed for workers who focused on the transcription. These results are an important step towards establishing new methods for investigating QoE in multimedia.}, address = {Athlone, Ireland}, author = {Schwind, Anika and Moldovan, Christian and Janiak, Tim and Dworschak, Nemo-Dario and Hoßfeld, Tobias}, booktitle = {12th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ua-net}, month = 5, title = {Don’t Stop the Music: Crowdsourced QoE Assessment of Music Streaming with Stalling}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-7 %A Schwind, Anika %A Moldovan, Christian %A Janiak, Tim %A Dworschak, Nemo-Dario %A Hoßfeld, Tobias %B 12th International Conference on Quality of Multimedia Experience (QoMEX) %C Athlone, Ireland %D 2020 %T Don’t Stop the Music: Crowdsourced QoE Assessment of Music Streaming with Stalling %X Streaming made a lasting effect on the way our society consumes media in the last decade. While due to streaming the way we listen to music and podcasts has changed drastically, there are very few studies about its Quality of Experience (QoE) and possible influence factors. From video QoE studies, we know that, for example, undesirable stops of the stream (stalling events) have a significant impact on QoE. However, the way in which music and video streaming is consumed differs significantly, as music is often played in the background, and thus, the influence of stalling could be significantly different. Thus, this work evaluates the impact of stalling on music streaming QoE. Therefore, we conduct two crowdsourced user studies: In the first study, users have to rate four songs with different stalling patterns and evaluate the degree of impairments. Afterwards, we compare the ratings to the results of a lab study and show that they are highly correlated, and that crowdsourcing is a suitable way of measuring music streaming QoE. In addition, we conduct a second crowdsourcing study to investigate the influence of the user's attentiveness on QoE. Here, participants have to listen to one song with two stalling events, while one half of them had to transcribe a handwritten text with music playing in the background. The attentiveness shows no influence on the perceived streaming quality, but it shows a significant influence on the perceived quality degradation due to stalling events. Furthermore, considerably more stalling events were missed for workers who focused on the transcription. These results are an important step towards establishing new methods for investigating QoE in multimedia.
• Are you on Mobile or Desktop? On the Impact of End-User Device on Web QoE Inference from Encrypted Traffic Wassermann, Sarah; Casas, Pedro; Ben Houidi, Zied; Huet, Alexis; Seufert, Michael; Wehner, Nikolas; Schüler, Joshua; Cai, Sheng-Ming; Shi, Hao; Xu, Jinchun; Hoßfeld, Tobias; Rossi, Dario in 16th International Conference on Network and Service Management (CNSM) (2020).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Web browsing is one of the key applications of the Internet, if not the most important one. We address the problem of Web Quality of Experience (QoE) monitoring from the ISP perspective, relying on in-network, passive measurements. As a proxy to Web QoE, we focus on the analysis of the well-known SpeedIndex (SI) metric. Given the lack of app-level data visibility introduced by the wide adoption of end-to-end encryption, we resort to machine-learning models to infer the SI and the QoE level of individual web page loading sessions, using as input only packet- and flow-level data. Our study targets the impact of different end-user device types (e.g., smartphone, desktop, tablet) on the performance of such models. Empirical evaluations on a large, multi-device, heterogeneous corpus of Web QoE measurements for top popular websites demonstrate that the proposed solution can infer the SI as well as estimate QoE ranges with high accuracy, using either packet-level or flow-level measurements. In addition, we show that the device type adds a strong bias in the feasibility of these Web QoE models, putting into question the applicability of previously conceived approaches on single-device measurements. To improve the state of affairs, we conceive cross-device generalizable models operating at both packet and flow levels, offering a feasible solution for Web QoE monitoring in operational, multi-device networks. To the best of our knowledge, this is the first study tackling the analysis of Web QoE from encrypted network traffic in multi-device scenarios.

  @inproceedings{info3-inproceedings-2020-10, abstract = {Web browsing is one of the key applications of the Internet, if not the most important one. We address the problem of Web Quality of Experience (QoE) monitoring from the ISP perspective, relying on in-network, passive measurements. As a proxy to Web QoE, we focus on the analysis of the well-known SpeedIndex (SI) metric. Given the lack of app-level data visibility introduced by the wide adoption of end-to-end encryption, we resort to machine-learning models to infer the SI and the QoE level of individual web page loading sessions, using as input only packet- and flow-level data. Our study targets the impact of different end-user device types (e.g., smartphone, desktop, tablet) on the performance of such models. Empirical evaluations on a large, multi-device, heterogeneous corpus of Web QoE measurements for top popular websites demonstrate that the proposed solution can infer the SI as well as estimate QoE ranges with high accuracy, using either packet-level or flow-level measurements. In addition, we show that the device type adds a strong bias in the feasibility of these Web QoE models, putting into question the applicability of previously conceived approaches on single-device measurements. To improve the state of affairs, we conceive cross-device generalizable models operating at both packet and flow levels, offering a feasible solution for Web QoE monitoring in operational, multi-device networks. To the best of our knowledge, this is the first study tackling the analysis of Web QoE from encrypted network traffic in multi-device scenarios.}, address = {Izmir, Turkey}, author = {Wassermann, Sarah and Casas, Pedro and Ben Houidi, Zied and Huet, Alexis and Seufert, Michael and Wehner, Nikolas and Schüler, Joshua and Cai, Sheng-Ming and Shi, Hao and Xu, Jinchun and Hoßfeld, Tobias and Rossi, Dario}, booktitle = {16th International Conference on Network and Service Management (CNSM)}, keywords = {ucn}, month = 11, title = {Are you on Mobile or Desktop? On the Impact of End-User Device on Web QoE Inference from Encrypted Traffic}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-10 %A Wassermann, Sarah %A Casas, Pedro %A Ben Houidi, Zied %A Huet, Alexis %A Seufert, Michael %A Wehner, Nikolas %A Schüler, Joshua %A Cai, Sheng-Ming %A Shi, Hao %A Xu, Jinchun %A Hoßfeld, Tobias %A Rossi, Dario %B 16th International Conference on Network and Service Management (CNSM) %C Izmir, Turkey %D 2020 %T Are you on Mobile or Desktop? On the Impact of End-User Device on Web QoE Inference from Encrypted Traffic %X Web browsing is one of the key applications of the Internet, if not the most important one. We address the problem of Web Quality of Experience (QoE) monitoring from the ISP perspective, relying on in-network, passive measurements. As a proxy to Web QoE, we focus on the analysis of the well-known SpeedIndex (SI) metric. Given the lack of app-level data visibility introduced by the wide adoption of end-to-end encryption, we resort to machine-learning models to infer the SI and the QoE level of individual web page loading sessions, using as input only packet- and flow-level data. Our study targets the impact of different end-user device types (e.g., smartphone, desktop, tablet) on the performance of such models. Empirical evaluations on a large, multi-device, heterogeneous corpus of Web QoE measurements for top popular websites demonstrate that the proposed solution can infer the SI as well as estimate QoE ranges with high accuracy, using either packet-level or flow-level measurements. In addition, we show that the device type adds a strong bias in the feasibility of these Web QoE models, putting into question the applicability of previously conceived approaches on single-device measurements. To improve the state of affairs, we conceive cross-device generalizable models operating at both packet and flow levels, offering a feasible solution for Web QoE monitoring in operational, multi-device networks. To the best of our knowledge, this is the first study tackling the analysis of Web QoE from encrypted network traffic in multi-device scenarios.
• Bounded Latency with Bridge-Local Stream Reservation and Strict Priority Queuing Grigorjew, Alexej; Metzger, Florian; Hoßfeld, Tobias; Specht, Johannes; Götz, Franz-Josef; Chen, Feng; Schmitt, Jürgen in 11th International Conference on Network of the Future (NoF) (2020).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  Bridge-local latency computation is often regarded with caution, while new shaping mechanisms and timed gates are developed to achieve deterministic guarantees. However, these new concepts require additional hardware support in the forwarding devices, and many of them are based on assumptions of central control and network-wide information being available. This document presents a per-hop latency bound for individual streams in a class-based network that applies the IEEE 802.1Q strict priority transmission selection algorithm. It does not rely on shaping or timed gates and uses the accumulated latency fields during the reservation process to provide upper bounds with bridge-local information. The presented delay bound is proven formally and then evaluated with respect to its accuracy. It shows that deterministic latency with priority queuing is indeed feasible, and it indicates the required information that must be provided during resource reservation, e.g., to protocols developed in IEEE 802.1Qdd.

  @inproceedings{info3-inproceedings-2020-17, abstract = {Bridge-local latency computation is often regarded with caution, while new shaping mechanisms and timed gates are developed to achieve deterministic guarantees. However, these new concepts require additional hardware support in the forwarding devices, and many of them are based on assumptions of central control and network-wide information being available. This document presents a per-hop latency bound for individual streams in a class-based network that applies the IEEE 802.1Q strict priority transmission selection algorithm. It does not rely on shaping or timed gates and uses the accumulated latency fields during the reservation process to provide upper bounds with bridge-local information. The presented delay bound is proven formally and then evaluated with respect to its accuracy. It shows that deterministic latency with priority queuing is indeed feasible, and it indicates the required information that must be provided during resource reservation, e.g., to protocols developed in IEEE 802.1Qdd.}, author = {Grigorjew, Alexej and Metzger, Florian and Hoßfeld, Tobias and Specht, Johannes and Götz, Franz-Josef and Chen, Feng and Schmitt, Jürgen}, booktitle = {11th International Conference on Network of the Future (NoF)}, keywords = {ats-performance}, month = 11, title = {Bounded Latency with Bridge-Local Stream Reservation and Strict Priority Queuing}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-17 %A Grigorjew, Alexej %A Metzger, Florian %A Hoßfeld, Tobias %A Specht, Johannes %A Götz, Franz-Josef %A Chen, Feng %A Schmitt, Jürgen %B 11th International Conference on Network of the Future (NoF) %D 2020 %T Bounded Latency with Bridge-Local Stream Reservation and Strict Priority Queuing %X Bridge-local latency computation is often regarded with caution, while new shaping mechanisms and timed gates are developed to achieve deterministic guarantees. However, these new concepts require additional hardware support in the forwarding devices, and many of them are based on assumptions of central control and network-wide information being available. This document presents a per-hop latency bound for individual streams in a class-based network that applies the IEEE 802.1Q strict priority transmission selection algorithm. It does not rely on shaping or timed gates and uses the accumulated latency fields during the reservation process to provide upper bounds with bridge-local information. The presented delay bound is proven formally and then evaluated with respect to its accuracy. It shows that deterministic latency with priority queuing is indeed feasible, and it indicates the required information that must be provided during resource reservation, e.g., to protocols developed in IEEE 802.1Qdd.
• Improving Web QoE Monitoring for Encrypted Network Traffic through Time Series Modeling Wehner, Nikolas; Seufert, Michael; Schüler, Joshua; Wassermann, Sarah; Casas, Pedro; Hoßfeld, Tobias in 2nd Workshop on AI in Networks and Distributed Systems (WAIN) (2020).
  • [ Abstract ]
  • [ BibTeX ]
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  This paper addresses the problem of Quality of Experience (QoE) monitoring for web browsing. In particular, the inference of common Web QoE metrics such as Speed Index (SI) is investigated. Based on a large dataset collected with open web-measurement platforms on different device-types, a unique feature set is designed and used to estimate the RUMSI -- an efficient approximation to SI, with machine-learning based regression and classification approaches. Results indicate that it is possible to estimate the RUMSI accurately, and that in particular, recurrent neural networks are highly suitable for the task, as they capture the network dynamics more precisely.

  @inproceedings{info3-inproceedings-2020-12, abstract = {This paper addresses the problem of Quality of Experience (QoE) monitoring for web browsing. In particular, the inference of common Web QoE metrics such as Speed Index (SI) is investigated. Based on a large dataset collected with open web-measurement platforms on different device-types, a unique feature set is designed and used to estimate the RUMSI – an efficient approximation to SI, with machine-learning based regression and classification approaches. Results indicate that it is possible to estimate the RUMSI accurately, and that in particular, recurrent neural networks are highly suitable for the task, as they capture the network dynamics more precisely.}, address = {Milan, Italy}, author = {Wehner, Nikolas and Seufert, Michael and Schüler, Joshua and Wassermann, Sarah and Casas, Pedro and Hoßfeld, Tobias}, booktitle = {2nd Workshop on AI in Networks and Distributed Systems (WAIN)}, keywords = {ucn}, month = 11, title = {Improving Web QoE Monitoring for Encrypted Network Traffic through Time Series Modeling}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-12 %A Wehner, Nikolas %A Seufert, Michael %A Schüler, Joshua %A Wassermann, Sarah %A Casas, Pedro %A Hoßfeld, Tobias %B 2nd Workshop on AI in Networks and Distributed Systems (WAIN) %C Milan, Italy %D 2020 %T Improving Web QoE Monitoring for Encrypted Network Traffic through Time Series Modeling %X This paper addresses the problem of Quality of Experience (QoE) monitoring for web browsing. In particular, the inference of common Web QoE metrics such as Speed Index (SI) is investigated. Based on a large dataset collected with open web-measurement platforms on different device-types, a unique feature set is designed and used to estimate the RUMSI -- an efficient approximation to SI, with machine-learning based regression and classification approaches. Results indicate that it is possible to estimate the RUMSI accurately, and that in particular, recurrent neural networks are highly suitable for the task, as they capture the network dynamics more precisely.
• Crowdsourced Network Measurements in Germany: Mobile Internet Experience from End User Perspective Schwind, Anika; Wamser, Florian; Hoßfeld, Tobias; Wunderer, Stefan; Tarnvik, Erik; Hall, Andy in Broadband Coverage in Germany; 14. ITG Symposium (2020).
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  Collecting and analyzing meaningful data in mobile networks is the key to assessing network performance. Crowdsourced Network Measurements (CNMs) provide insights beyond the network layer and offer performance and other measurements at the application and user-level towards Quality of Experience (QoE). In this paper, the mobile Internet experience for Germany is evaluated with the help of crowdsourcing from the perspective of an end user. We statistically analyze a dataset with throughput measurements on the end device from Tutela Ltd., which covers more than 2.5 million throughput tests across Germany from January to July 2019. We give insights into this emerging methodology and highlight the benefits of this method. The paper contains statistics and conclusions for several large cities as well as regions in Germany compared to general statements for Germany, since individual measurements and averages often only imprecisely reflect the situation. The goal is to give a holistic view of the performance of the current mobile network in Germany. Reading this paper, it becomes evident that reliable statements about the quality of the mobile network for Germany depend on a large number of peculiarities in different regions with their own performance characteristics due to different network deployments and population numbers.

  @inproceedings{info3-inproceedings-2020-13, abstract = {Collecting and analyzing meaningful data in mobile networks is the key to assessing network performance. Crowdsourced Network Measurements (CNMs) provide insights beyond the network layer and offer performance and other measurements at the application and user-level towards Quality of Experience (QoE). In this paper, the mobile Internet experience for Germany is evaluated with the help of crowdsourcing from the perspective of an end user. We statistically analyze a dataset with throughput measurements on the end device from Tutela Ltd., which covers more than 2.5 million throughput tests across Germany from January to July 2019. We give insights into this emerging methodology and highlight the benefits of this method. The paper contains statistics and conclusions for several large cities as well as regions in Germany compared to general statements for Germany, since individual measurements and averages often only imprecisely reflect the situation. The goal is to give a holistic view of the performance of the current mobile network in Germany. Reading this paper, it becomes evident that reliable statements about the quality of the mobile network for Germany depend on a large number of peculiarities in different regions with their own performance characteristics due to different network deployments and population numbers.}, address = {Berlin}, author = {Schwind, Anika and Wamser, Florian and Hoßfeld, Tobias and Wunderer, Stefan and Tarnvik, Erik and Hall, Andy}, booktitle = {Broadband Coverage in Germany; 14. ITG Symposium}, keywords = {can}, month = 8, title = {Crowdsourced Network Measurements in Germany: Mobile Internet Experience from End User Perspective}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-13 %A Schwind, Anika %A Wamser, Florian %A Hoßfeld, Tobias %A Wunderer, Stefan %A Tarnvik, Erik %A Hall, Andy %B Broadband Coverage in Germany; 14. ITG Symposium %C Berlin %D 2020 %T Crowdsourced Network Measurements in Germany: Mobile Internet Experience from End User Perspective %X Collecting and analyzing meaningful data in mobile networks is the key to assessing network performance. Crowdsourced Network Measurements (CNMs) provide insights beyond the network layer and offer performance and other measurements at the application and user-level towards Quality of Experience (QoE). In this paper, the mobile Internet experience for Germany is evaluated with the help of crowdsourcing from the perspective of an end user. We statistically analyze a dataset with throughput measurements on the end device from Tutela Ltd., which covers more than 2.5 million throughput tests across Germany from January to July 2019. We give insights into this emerging methodology and highlight the benefits of this method. The paper contains statistics and conclusions for several large cities as well as regions in Germany compared to general statements for Germany, since individual measurements and averages often only imprecisely reflect the situation. The goal is to give a holistic view of the performance of the current mobile network in Germany. Reading this paper, it becomes evident that reliable statements about the quality of the mobile network for Germany depend on a large number of peculiarities in different regions with their own performance characteristics due to different network deployments and population numbers.
• Simulative Evaluation of KPIs in SDN for Topology Classification and Performance Prediction Models Gray, Nicholas; Dietz, Katharina; Hoßfeld, Tobias in 2020 16th International Conference on Network and Service Management (CNSM) (2020).
  • [ Abstract ]
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  In recent years Software-defined Networking (SDN) has gained increased popularity by reducing the complexity of management operations and increasing the performance of networks. As a result, the number of purchasable SDN devices and their deployment in real world network constantly rises, making a thorough understanding of their behaviors and interactions even more important. In this work we analyze distributed controller architectures via simulation, identify Key Performance Indicators (KPIs), classify various network topologies with respect to their impact on SDN, as well as create a prediction model to estimate the overall performance of the overall SDN ecosystem, which can be used for network planning.

  @inproceedings{info3-inproceedings-2020-15, abstract = {In recent years Software-defined Networking (SDN) has gained increased popularity by reducing the complexity of management operations and increasing the performance of networks. As a result, the number of purchasable SDN devices and their deployment in real world network constantly rises, making a thorough understanding of their behaviors and interactions even more important. In this work we analyze distributed controller architectures via simulation, identify Key Performance Indicators (KPIs), classify various network topologies with respect to their impact on SDN, as well as create a prediction model to estimate the overall performance of the overall SDN ecosystem, which can be used for network planning.}, author = {Gray, Nicholas and Dietz, Katharina and Hoßfeld, Tobias}, booktitle = {2020 16th International Conference on Network and Service Management (CNSM)}, keywords = {sys:hidden:inproceedings}, title = {Simulative Evaluation of KPIs in SDN for Topology Classification and Performance Prediction Models}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-15 %A Gray, Nicholas %A Dietz, Katharina %A Hoßfeld, Tobias %B 2020 16th International Conference on Network and Service Management (CNSM) %D 2020 %T Simulative Evaluation of KPIs in SDN for Topology Classification and Performance Prediction Models %X In recent years Software-defined Networking (SDN) has gained increased popularity by reducing the complexity of management operations and increasing the performance of networks. As a result, the number of purchasable SDN devices and their deployment in real world network constantly rises, making a thorough understanding of their behaviors and interactions even more important. In this work we analyze distributed controller architectures via simulation, identify Key Performance Indicators (KPIs), classify various network topologies with respect to their impact on SDN, as well as create a prediction model to estimate the overall performance of the overall SDN ecosystem, which can be used for network planning.
• Poster: Per-Hop Bridge-Local Latency Bounds with Strict Priority Transmission Selection Grigorjew, Alexej; Metzger, Florian; Hoßfeld, Tobias; Specht, Johannes; Götz, Franz-Josef; Chen, Feng; Schmitt, Jürgen in IFIP Networking Conference (2020).
  • [ Abstract ]
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  This work presents a proven per-hop latency bound for real-time networks with admission control that does not rely on shaping or timed gates. It can be applied in a distributed control plane using only bridge-local information, making it an ideal candidate for brownfield real-time network installations. A brief comparison with Asynchronous Traffic Shaping (ATS) shows that the achieved network utilization is comparable to that of ATS in some scenarios, while it only lags behind in scenarios with accumulating bursts where re-shaping could actually reduce the interference of the observed streams.

  @inproceedings{info3-inproceedings-2020-16, abstract = {This work presents a proven per-hop latency bound for real-time networks with admission control that does not rely on shaping or timed gates. It can be applied in a distributed control plane using only bridge-local information, making it an ideal candidate for brownfield real-time network installations. A brief comparison with Asynchronous Traffic Shaping (ATS) shows that the achieved network utilization is comparable to that of ATS in some scenarios, while it only lags behind in scenarios with accumulating bursts where re-shaping could actually reduce the interference of the observed streams.}, author = {Grigorjew, Alexej and Metzger, Florian and Hoßfeld, Tobias and Specht, Johannes and Götz, Franz-Josef and Chen, Feng and Schmitt, Jürgen}, booktitle = {IFIP Networking Conference}, keywords = {ats-performance}, month = 6, title = {Poster: Per-Hop Bridge-Local Latency Bounds with Strict Priority Transmission Selection}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-16 %A Grigorjew, Alexej %A Metzger, Florian %A Hoßfeld, Tobias %A Specht, Johannes %A Götz, Franz-Josef %A Chen, Feng %A Schmitt, Jürgen %B IFIP Networking Conference %D 2020 %T Poster: Per-Hop Bridge-Local Latency Bounds with Strict Priority Transmission Selection %X This work presents a proven per-hop latency bound for real-time networks with admission control that does not rely on shaping or timed gates. It can be applied in a distributed control plane using only bridge-local information, making it an ideal candidate for brownfield real-time network installations. A brief comparison with Asynchronous Traffic Shaping (ATS) shows that the achieved network utilization is comparable to that of ATS in some scenarios, while it only lags behind in scenarios with accumulating bursts where re-shaping could actually reduce the interference of the observed streams.
• Mind the (QoE) Gap: On the Incompatibility of Web and Video QoE Models in the Wild Seufert, Michael; Wehner, Nikolas; Wieser, Viktoria; Casas, Pedro; Capdehourat, Germán in 16th International Conference on Network and Service Management (CNSM) (2020).
  • [ Abstract ]
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  Education Service Providers (ESPs) have a paramount role in the digitization of education, providing reliable devices for students and teachers and high quality Internet access at schools. In this paper, a large-scale, passive, in-device Quality of Experience (QoE) monitoring system is presented, which was deployed into a nationwide network of education-purpose devices. Four months' worth of continuous measurements were conducted by an ESP, covering more than 800 education centers and about 4000 devices, used both in schools and at home. When analyzing the QoE of web sessions in school networks, we identify a fundamental issue with the compatibility of web browsing and video QoE models, which inhibits the successful application of QoE-aware network management for multiple services.

  @inproceedings{info3-inproceedings-2020-11, abstract = {Education Service Providers (ESPs) have a paramount role in the digitization of education, providing reliable devices for students and teachers and high quality Internet access at schools. In this paper, a large-scale, passive, in-device Quality of Experience (QoE) monitoring system is presented, which was deployed into a nationwide network of education-purpose devices. Four months' worth of continuous measurements were conducted by an ESP, covering more than 800 education centers and about 4000 devices, used both in schools and at home. When analyzing the QoE of web sessions in school networks, we identify a fundamental issue with the compatibility of web browsing and video QoE models, which inhibits the successful application of QoE-aware network management for multiple services.}, address = {Izmir, Turkey}, author = {Seufert, Michael and Wehner, Nikolas and Wieser, Viktoria and Casas, Pedro and Capdehourat, Germán}, booktitle = {16th International Conference on Network and Service Management (CNSM)}, keywords = {ucn}, month = 11, title = {Mind the (QoE) Gap: On the Incompatibility of Web and Video QoE Models in the Wild}, year = 2020 }

  %0 Conference Paper %1 info3-inproceedings-2020-11 %A Seufert, Michael %A Wehner, Nikolas %A Wieser, Viktoria %A Casas, Pedro %A Capdehourat, Germán %B 16th International Conference on Network and Service Management (CNSM) %C Izmir, Turkey %D 2020 %T Mind the (QoE) Gap: On the Incompatibility of Web and Video QoE Models in the Wild %X Education Service Providers (ESPs) have a paramount role in the digitization of education, providing reliable devices for students and teachers and high quality Internet access at schools. In this paper, a large-scale, passive, in-device Quality of Experience (QoE) monitoring system is presented, which was deployed into a nationwide network of education-purpose devices. Four months' worth of continuous measurements were conducted by an ESP, covering more than 800 education centers and about 4000 devices, used both in schools and at home. When analyzing the QoE of web sessions in school networks, we identify a fundamental issue with the compatibility of web browsing and video QoE models, which inhibits the successful application of QoE-aware network management for multiple services.

• The Interplay between QoE, User Behavior and System Blocking in QoE Management Hoßfeld, Tobias; Atzori, Luigi; Heegaard, Poul E.; Skorin-Kapov, Lea; Varela, Martin in 22nd Conference on Innovation in Clouds, Internet and Networks and Workshops (ICIN) (2019).
  • [ BibTeX ]
  • [ EndNote ]
  @inproceedings{info3-inproceedings-2019-15, author = {Hoßfeld, Tobias and Atzori, Luigi and Heegaard, Poul E. and Skorin-Kapov, Lea and Varela, Martin}, booktitle = {22nd Conference on Innovation in Clouds, Internet and Networks and Workshops (ICIN)}, keywords = {sys:hidden:inproceedings}, title = {The Interplay between QoE, User Behavior and System Blocking in QoE Management}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-15 %A Hoßfeld, Tobias %A Atzori, Luigi %A Heegaard, Poul E. %A Skorin-Kapov, Lea %A Varela, Martin %B 22nd Conference on Innovation in Clouds, Internet and Networks and Workshops (ICIN) %D 2019 %T The Interplay between QoE, User Behavior and System Blocking in QoE Management
• A Simulation of Asynchronous Traffic Shapers in Switched Ethernet Networks Grigorjew, Alexej; Metzger, Florian; Hoßfeld, Tobias; Specht, Johannes in Workshop for Advanced Communication Networks for Industrial Applications (2019).
  • [ Abstract ]
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  As the requirements of real-time networking in- crease, the IEEE Time-Sensitive Networking (TSN) task group is working on new standards for high bandwidth and low latency Ethernet switching. In particular, the upcoming P802.1Qcr standard features Asynchronous Traffic Shaping (ATS), which is a promising approach for real-time networks with high dynamics and critical safety requirements. Additionally, parallel concepts such as frame preemption can be used to reduce delays even further. This work presents a discrete event simulation framework that can analyze the performance of these concepts. It implements frame preemption and multiple shaping algorithms, while recording latency and queue utilization statistics at the switches. In addition, an evaluation of a linear topology with four switches is performed under high link utilization, which demonstrates the benefit of the above mechanisms compared to regular Ethernet switching.

  @inproceedings{info3-inproceedings-2019-16, abstract = {As the requirements of real-time networking in- crease, the IEEE Time-Sensitive Networking (TSN) task group is working on new standards for high bandwidth and low latency Ethernet switching. In particular, the upcoming P802.1Qcr standard features Asynchronous Traffic Shaping (ATS), which is a promising approach for real-time networks with high dynamics and critical safety requirements. Additionally, parallel concepts such as frame preemption can be used to reduce delays even further. This work presents a discrete event simulation framework that can analyze the performance of these concepts. It implements frame preemption and multiple shaping algorithms, while recording latency and queue utilization statistics at the switches. In addition, an evaluation of a linear topology with four switches is performed under high link utilization, which demonstrates the benefit of the above mechanisms compared to regular Ethernet switching.}, author = {Grigorjew, Alexej and Metzger, Florian and Hoßfeld, Tobias and Specht, Johannes}, booktitle = {Workshop for Advanced Communication Networks for Industrial Applications}, keywords = {ngn}, month = 3, title = {A Simulation of Asynchronous Traffic Shapers in Switched Ethernet Networks}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-16 %A Grigorjew, Alexej %A Metzger, Florian %A Hoßfeld, Tobias %A Specht, Johannes %B Workshop for Advanced Communication Networks for Industrial Applications %D 2019 %T A Simulation of Asynchronous Traffic Shapers in Switched Ethernet Networks %X As the requirements of real-time networking in- crease, the IEEE Time-Sensitive Networking (TSN) task group is working on new standards for high bandwidth and low latency Ethernet switching. In particular, the upcoming P802.1Qcr standard features Asynchronous Traffic Shaping (ATS), which is a promising approach for real-time networks with high dynamics and critical safety requirements. Additionally, parallel concepts such as frame preemption can be used to reduce delays even further. This work presents a discrete event simulation framework that can analyze the performance of these concepts. It implements frame preemption and multiple shaping algorithms, while recording latency and queue utilization statistics at the switches. In addition, an evaluation of a linear topology with four switches is performed under high link utilization, which demonstrates the benefit of the above mechanisms compared to regular Ethernet switching.
• Modeling of Traffic Flows in Internet of Things Using Renewal Approximation Wamser, Florian; Tran-Gia, Phuoc; Geissler, Stefan; Hoßfeld, Tobias in International Conference on Optimization and Decision Science (ODS2019) (2019).
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  This paper proposes a versatile approach to model aggregated traffic flows in the Internet of Things (IoT) using renewal approximation. The modeled traffic originates from a large number of sources or devices consisting of a set of sensors mixed with classical elastic random traffic modeled as Poisson arrival process. The work shows the exact derivation in the simple case for periodic sensors. It shows further results in the mixed case with periodic sensors and a background process. The renewal approximation allows to derive the required number of sensors such that the aggregated traffic can be approximated as Poisson process.

  @inproceedings{info3-article-2019-8, abstract = {This paper proposes a versatile approach to model aggregated traffic flows in the Internet of Things (IoT) using renewal approximation. The modeled traffic originates from a large number of sources or devices consisting of a set of sensors mixed with classical elastic random traffic modeled as Poisson arrival process. The work shows the exact derivation in the simple case for periodic sensors. It shows further results in the mixed case with periodic sensors and a background process. The renewal approximation allows to derive the required number of sensors such that the aggregated traffic can be approximated as Poisson process.}, author = {Wamser, Florian and Tran-Gia, Phuoc and Geissler, Stefan and Hoßfeld, Tobias}, booktitle = {International Conference on Optimization and Decision Science (ODS2019)}, keywords = {net-man}, month = 9, title = {Modeling of Traffic Flows in Internet of Things Using Renewal Approximation}, year = 2019 }

  %0 Conference Paper %1 info3-article-2019-8 %A Wamser, Florian %A Tran-Gia, Phuoc %A Geissler, Stefan %A Hoßfeld, Tobias %B International Conference on Optimization and Decision Science (ODS2019) %D 2019 %T Modeling of Traffic Flows in Internet of Things Using Renewal Approximation %X This paper proposes a versatile approach to model aggregated traffic flows in the Internet of Things (IoT) using renewal approximation. The modeled traffic originates from a large number of sources or devices consisting of a set of sensors mixed with classical elastic random traffic modeled as Poisson arrival process. The work shows the exact derivation in the simple case for periodic sensors. It shows further results in the mixed case with periodic sensors and a background process. The renewal approximation allows to derive the required number of sensors such that the aggregated traffic can be approximated as Poisson process.
• User Behavior and Engagement of a Mobile Video Streaming User from Crowdsourced Measurements Moldovan, Christian; Wamser, Florian; Hoßfeld, Tobias in 2019 Eleventh International Conference on Quality of Multimedia Experience (QoMEX) (2019).
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  Mobile video streaming has gained a lot of popularity in recent year with the introduction of large data plans for mobile phones. While users in non-mobile scenarios have become accustomed to high quality and few stalling events, this is not the case in mobile environments. People are more likely to tolerate stalling since they know high throughput coverage cannot always be guaranteed. Their behavior and their engagement are drastically different when watching videos on mobile devices. In this paper, we characterize mobile phone users who use a video streaming application. We present a data set of over 6,000 video views from a crowdsourced video measurement study. We investigate user activity and engagement during video streaming and how such metrics are correlated with each other. This is the first study that goes beyond user engagement and investigates the direct behavior of mobile video users outside the lab which is an important step towards mobile QoE management.

  @inproceedings{info3-inproceedings-2019-21, abstract = {Mobile video streaming has gained a lot of popularity in recent year with the introduction of large data plans for mobile phones. While users in non-mobile scenarios have become accustomed to high quality and few stalling events, this is not the case in mobile environments. People are more likely to tolerate stalling since they know high throughput coverage cannot always be guaranteed. Their behavior and their engagement are drastically different when watching videos on mobile devices. In this paper, we characterize mobile phone users who use a video streaming application. We present a data set of over 6,000 video views from a crowdsourced video measurement study. We investigate user activity and engagement during video streaming and how such metrics are correlated with each other. This is the first study that goes beyond user engagement and investigates the direct behavior of mobile video users outside the lab which is an important step towards mobile QoE management.}, author = {Moldovan, Christian and Wamser, Florian and Hoßfeld, Tobias}, booktitle = {2019 Eleventh International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {can}, month = 6, title = {User Behavior and Engagement of a Mobile Video Streaming User from Crowdsourced Measurements}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-21 %A Moldovan, Christian %A Wamser, Florian %A Hoßfeld, Tobias %B 2019 Eleventh International Conference on Quality of Multimedia Experience (QoMEX) %D 2019 %T User Behavior and Engagement of a Mobile Video Streaming User from Crowdsourced Measurements %X Mobile video streaming has gained a lot of popularity in recent year with the introduction of large data plans for mobile phones. While users in non-mobile scenarios have become accustomed to high quality and few stalling events, this is not the case in mobile environments. People are more likely to tolerate stalling since they know high throughput coverage cannot always be guaranteed. Their behavior and their engagement are drastically different when watching videos on mobile devices. In this paper, we characterize mobile phone users who use a video streaming application. We present a data set of over 6,000 video views from a crowdsourced video measurement study. We investigate user activity and engagement during video streaming and how such metrics are correlated with each other. This is the first study that goes beyond user engagement and investigates the direct behavior of mobile video users outside the lab which is an important step towards mobile QoE management.
• QoE Analysis of Spotify Audio Streaming and App Browsing Schwind, Anika; Haberzettl, Lorenz; Wamser, Florian; Hoßfeld, Tobias in 4th Internet-QoE Workshop: QoE-based Analysis and Management of Data Communication Networks (Internet-QoE’19) (2019).
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  Spotify is the most-listened audio streaming provider in 2019 with 217 million active users per month. Providers are therefore interested in the quality and functionality of Spotify in order to provide their users with the best possible streaming quality. While video streaming services such as Netflix and their streaming approach have been extensively explored in previous research, audio streaming services like Spotify and their corresponding behavior at certain network conditions have not been considered in detail yet. In this paper, we perform a QoE analysis under various network conditions and examine the app browsing performance of the audio streaming platform Spotify using its native Android mobile application. We have developed a measurement tool that emulates a user listening to audio through Spotify. While streaming, application and network layer parameters are captured that have a high correlation to the user’s QoE. The paper shows a baseline scenario including the streaming of a single song as well as playlist streaming behavior. Next, the effect of interruptions on the streaming behavior is evaluated and finally, the influence of network impairments on QoE key performance indicators such as initial delay is shown.

  @inproceedings{info3-inproceedings-2019-27, abstract = {Spotify is the most-listened audio streaming provider in 2019 with 217 million active users per month. Providers are therefore interested in the quality and functionality of Spotify in order to provide their users with the best possible streaming quality. While video streaming services such as Netflix and their streaming approach have been extensively explored in previous research, audio streaming services like Spotify and their corresponding behavior at certain network conditions have not been considered in detail yet. In this paper, we perform a QoE analysis under various network conditions and examine the app browsing performance of the audio streaming platform Spotify using its native Android mobile application. We have developed a measurement tool that emulates a user listening to audio through Spotify. While streaming, application and network layer parameters are captured that have a high correlation to the user’s QoE. The paper shows a baseline scenario including the streaming of a single song as well as playlist streaming behavior. Next, the effect of interruptions on the streaming behavior is evaluated and finally, the influence of network impairments on QoE key performance indicators such as initial delay is shown.}, author = {Schwind, Anika and Haberzettl, Lorenz and Wamser, Florian and Hoßfeld, Tobias}, booktitle = {4th Internet-QoE Workshop: QoE-based Analysis and Management of Data Communication Networks (Internet-QoE'19)}, keywords = {can}, month = 10, title = {QoE Analysis of Spotify Audio Streaming and App Browsing}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-27 %A Schwind, Anika %A Haberzettl, Lorenz %A Wamser, Florian %A Hoßfeld, Tobias %B 4th Internet-QoE Workshop: QoE-based Analysis and Management of Data Communication Networks (Internet-QoE'19) %D 2019 %T QoE Analysis of Spotify Audio Streaming and App Browsing %X Spotify is the most-listened audio streaming provider in 2019 with 217 million active users per month. Providers are therefore interested in the quality and functionality of Spotify in order to provide their users with the best possible streaming quality. While video streaming services such as Netflix and their streaming approach have been extensively explored in previous research, audio streaming services like Spotify and their corresponding behavior at certain network conditions have not been considered in detail yet. In this paper, we perform a QoE analysis under various network conditions and examine the app browsing performance of the audio streaming platform Spotify using its native Android mobile application. We have developed a measurement tool that emulates a user listening to audio through Spotify. While streaming, application and network layer parameters are captured that have a high correlation to the user’s QoE. The paper shows a baseline scenario including the streaming of a single song as well as playlist streaming behavior. Next, the effect of interruptions on the streaming behavior is evaluated and finally, the influence of network impairments on QoE key performance indicators such as initial delay is shown.
• To Share or Not to Share? How Exploitation of Context Data Can Improve In-Network QoE Monitoring of Encrypted YouTube Streams Orsolic, Irena; Skorin-Kapov, Lea; Hoßfeld, Tobias in 2019 Eleventh International Conference on Quality of Multimedia Experience (QoMEX) (QoMEX 2019) (2019).
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  With the widespread use of encryption in Over the Top (OTT) traffic, Internet Service Providers (ISPs) for the most part lack insights into application performance, as well as into Quality of Experience (QoE) perceived by end users. Addressing challenges related to encryption, ISPs are looking into machine learning based solutions that can detect application performance solely from statistical properties of the traffic. On the other hand, OTT service providers are not willing to share service performance and content-related information with ISPs. While related work on OTT-ISP collaboration scenarios has addressed architectural aspects, business models, and to a certain extent incentives for sharing data, the focus of this paper is on the exchanged data itself. We investigate to what extent the performance of in-network machine learning based QoE estimation models for HTTP adaptive video streaming could be improved with the availability of certain context data provided by OTT providers. We motivate OTT-ISP collaboration through more accurate in-network QoE monitoring and potential improvement of user experience, which is of interest to both sides.

  @inproceedings{info3-article-2019-9, abstract = {With the widespread use of encryption in Over the Top (OTT) traffic, Internet Service Providers (ISPs) for the most part lack insights into application performance, as well as into Quality of Experience (QoE) perceived by end users. Addressing challenges related to encryption, ISPs are looking into machine learning based solutions that can detect application performance solely from statistical properties of the traffic. On the other hand, OTT service providers are not willing to share service performance and content-related information with ISPs. While related work on OTT-ISP collaboration scenarios has addressed architectural aspects, business models, and to a certain extent incentives for sharing data, the focus of this paper is on the exchanged data itself. We investigate to what extent the performance of in-network machine learning based QoE estimation models for HTTP adaptive video streaming could be improved with the availability of certain context data provided by OTT providers. We motivate OTT-ISP collaboration through more accurate in-network QoE monitoring and potential improvement of user experience, which is of interest to both sides.}, author = {Orsolic, Irena and Skorin-Kapov, Lea and Hoßfeld, Tobias}, booktitle = {2019 Eleventh International Conference on Quality of Multimedia Experience (QoMEX) (QoMEX 2019)}, keywords = {traffic}, month = 6, title = {To Share or Not to Share? How Exploitation of Context Data Can Improve In-Network QoE Monitoring of Encrypted YouTube Streams}, year = 2019 }

  %0 Conference Paper %1 info3-article-2019-9 %A Orsolic, Irena %A Skorin-Kapov, Lea %A Hoßfeld, Tobias %B 2019 Eleventh International Conference on Quality of Multimedia Experience (QoMEX) (QoMEX 2019) %D 2019 %T To Share or Not to Share? How Exploitation of Context Data Can Improve In-Network QoE Monitoring of Encrypted YouTube Streams %X With the widespread use of encryption in Over the Top (OTT) traffic, Internet Service Providers (ISPs) for the most part lack insights into application performance, as well as into Quality of Experience (QoE) perceived by end users. Addressing challenges related to encryption, ISPs are looking into machine learning based solutions that can detect application performance solely from statistical properties of the traffic. On the other hand, OTT service providers are not willing to share service performance and content-related information with ISPs. While related work on OTT-ISP collaboration scenarios has addressed architectural aspects, business models, and to a certain extent incentives for sharing data, the focus of this paper is on the exchanged data itself. We investigate to what extent the performance of in-network machine learning based QoE estimation models for HTTP adaptive video streaming could be improved with the availability of certain context data provided by OTT providers. We motivate OTT-ISP collaboration through more accurate in-network QoE monitoring and potential improvement of user experience, which is of interest to both sides.
• Fundamental Relationships for Deriving QoE in Systems Hoßfeld, Tobias; Heegaard, Poul E.; Skorin-Kapov, Lea; Varela, Martin in 2019 Eleventh International Conference on Quality of Multimedia Experience (QoMEX) (QoMEX 2019) (2019).
  • [ Abstract ]
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  In the context of subjective user studies conducted to derive relationships between influence factors and QoE, user diversity leads to distributions of user scores for test conditions. Such models are commonly exploited by service/network providers to derive various QoE metrics in their system, such as expected QoE, or the percentage of users rating above a certain threshold. The question arises as to how to combine a) user rating distributions obtained from subjective studies, and b) system performance condition distributions, so as to obtain the actual observed QoE distribution in the system? Moreover, how can various QoE metrics of interest in the system be derived? We prove a fundamental relationship showing that the expected system QoE is equal to the expected Mean Opinion Score (MOS) in the system. While subjective user studies commonly report only QoS-to-MOS mapping functions, we show that to derive additional QoE metrics in the system, it is necessary to use corresponding QoS-to-QoE metric mapping functions (beyond only QoS-to-MOS) as derived from user rating distributions in subjective studies. The results of the paper provide important insights for deriving QoE metrics from a systems perspective.

  @inproceedings{info3-inproceedings-2019-23, abstract = {In the context of subjective user studies conducted to derive relationships between influence factors and QoE, user diversity leads to distributions of user scores for test conditions. Such models are commonly exploited by service/network providers to derive various QoE metrics in their system, such as expected QoE, or the percentage of users rating above a certain threshold. The question arises as to how to combine a) user rating distributions obtained from subjective studies, and b) system performance condition distributions, so as to obtain the actual observed QoE distribution in the system? Moreover, how can various QoE metrics of interest in the system be derived? We prove a fundamental relationship showing that the expected system QoE is equal to the expected Mean Opinion Score (MOS) in the system. While subjective user studies commonly report only QoS-to-MOS mapping functions, we show that to derive additional QoE metrics in the system, it is necessary to use corresponding QoS-to-QoE metric mapping functions (beyond only QoS-to-MOS) as derived from user rating distributions in subjective studies. The results of the paper provide important insights for deriving QoE metrics from a systems perspective.}, author = {Hoßfeld, Tobias and Heegaard, Poul E. and Skorin-Kapov, Lea and Varela, Martin}, booktitle = {2019 Eleventh International Conference on Quality of Multimedia Experience (QoMEX) (QoMEX 2019)}, keywords = {sys:hidden:inproceedings}, title = {Fundamental Relationships for Deriving QoE in Systems}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-23 %A Hoßfeld, Tobias %A Heegaard, Poul E. %A Skorin-Kapov, Lea %A Varela, Martin %B 2019 Eleventh International Conference on Quality of Multimedia Experience (QoMEX) (QoMEX 2019) %D 2019 %T Fundamental Relationships for Deriving QoE in Systems %X In the context of subjective user studies conducted to derive relationships between influence factors and QoE, user diversity leads to distributions of user scores for test conditions. Such models are commonly exploited by service/network providers to derive various QoE metrics in their system, such as expected QoE, or the percentage of users rating above a certain threshold. The question arises as to how to combine a) user rating distributions obtained from subjective studies, and b) system performance condition distributions, so as to obtain the actual observed QoE distribution in the system? Moreover, how can various QoE metrics of interest in the system be derived? We prove a fundamental relationship showing that the expected system QoE is equal to the expected Mean Opinion Score (MOS) in the system. While subjective user studies commonly report only QoS-to-MOS mapping functions, we show that to derive additional QoE metrics in the system, it is necessary to use corresponding QoS-to-QoE metric mapping functions (beyond only QoS-to-MOS) as derived from user rating distributions in subjective studies. The results of the paper provide important insights for deriving QoE metrics from a systems perspective.
• Crowd-based Study of Gameplay Impairments and Player Performance in DOTA 2 Hirth, Matthias; Borchert, Kathrin; Allendorf, Fabian; Metzger, Florian; Hoßfeld, Tobias in 4th Internet-QoE Workshop: QoE-based Analysis and Management of Data Communication Networks (Internet-QoE’19) (2019).
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  @inproceedings{info3-inproceedings-2019-24, address = {Los Cabos, Mexico}, author = {Hirth, Matthias and Borchert, Kathrin and Allendorf, Fabian and Metzger, Florian and Hoßfeld, Tobias}, booktitle = {4th Internet-QoE Workshop: QoE-based Analysis and Management of Data Communication Networks (Internet-QoE'19)}, keywords = {ua-net}, month = 10, title = {Crowd-based Study of Gameplay Impairments and Player Performance in DOTA 2}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-24 %A Hirth, Matthias %A Borchert, Kathrin %A Allendorf, Fabian %A Metzger, Florian %A Hoßfeld, Tobias %B 4th Internet-QoE Workshop: QoE-based Analysis and Management of Data Communication Networks (Internet-QoE'19) %C Los Cabos, Mexico %D 2019 %T Crowd-based Study of Gameplay Impairments and Player Performance in DOTA 2
• From click to playback: a dataset to study the response time of mobile YouTube Loh, Frank; Wamser, Florian; Moldovan, Christian; Zeidler, Bernd; Hoßfeld, Tobias; Tsilimantos, Dimitrios; Valentin, Stefan in Proceedings of the 10th ACM Multimedia Systems Conference (2019). 267–272.
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  Responding fluently to user requests is important to keep them immersed. In this paper, we are presenting an extensive dataset to study the response time of YouTube's mobile video streaming service on Android. We illustrate the application of our dataset by studying YouTube's initial delay for a subset of 9 videos in 75 network scenarios. We find that in 41% of the cases, YouTube exceeds the attention span of a typical user, while deep immersion is only reached in 15% of the cases. Our factor analysis implies that the allocation of the initial CDN node is the critical link in this delay chain. Since our dataset includes a large variety of factors, we are describing setup, methodology, and data structure in detail. Our dataset and measurement tools are publicly available.

  @inproceedings{info3-inproceedings-2019-25, abstract = {Responding fluently to user requests is important to keep them immersed. In this paper, we are presenting an extensive dataset to study the response time of YouTube's mobile video streaming service on Android. We illustrate the application of our dataset by studying YouTube's initial delay for a subset of 9 videos in 75 network scenarios. We find that in 41% of the cases, YouTube exceeds the attention span of a typical user, while deep immersion is only reached in 15% of the cases. Our factor analysis implies that the allocation of the initial CDN node is the critical link in this delay chain. Since our dataset includes a large variety of factors, we are describing setup, methodology, and data structure in detail. Our dataset and measurement tools are publicly available.}, author = {Loh, Frank and Wamser, Florian and Moldovan, Christian and Zeidler, Bernd and Hoßfeld, Tobias and Tsilimantos, Dimitrios and Valentin, Stefan}, booktitle = {Proceedings of the 10th ACM Multimedia Systems Conference}, keywords = {can}, month = 6, pages = {267-272}, title = {From click to playback: a dataset to study the response time of mobile YouTube}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-25 %A Loh, Frank %A Wamser, Florian %A Moldovan, Christian %A Zeidler, Bernd %A Hoßfeld, Tobias %A Tsilimantos, Dimitrios %A Valentin, Stefan %B Proceedings of the 10th ACM Multimedia Systems Conference %D 2019 %P 267-272 %T From click to playback: a dataset to study the response time of mobile YouTube %X Responding fluently to user requests is important to keep them immersed. In this paper, we are presenting an extensive dataset to study the response time of YouTube's mobile video streaming service on Android. We illustrate the application of our dataset by studying YouTube's initial delay for a subset of 9 videos in 75 network scenarios. We find that in 41% of the cases, YouTube exceeds the attention span of a typical user, while deep immersion is only reached in 15% of the cases. Our factor analysis implies that the allocation of the initial CDN node is the critical link in this delay chain. Since our dataset includes a large variety of factors, we are describing setup, methodology, and data structure in detail. Our dataset and measurement tools are publicly available.
• Discrete-Time Analysis of the Blockchain Distributed Ledger Technology Geissler, Stefan; Prantl, Thomas; Lange, Stanislav; Wamser, Florian; Hoßfeld, Tobias in 31st International Teletraffic Congress (ITC). , Budapest, Hungary (2019).
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  Blockchain and distributed ledger technologies have become more and more popular and widespread during recent years. After the initial hype about the technology and many cryptocurrency related use cases, the technology slowly starts to make its way into other domains like food tracking and document management. In order to further contribute to the search of what this technology can be used for, more detailed performance evaluations are required in order to investigate key performance indicators and general limits of the technology. To this end, we develop a discrete-time queueing model that allows a detailed evaluation of the characteristics of a blockchain system, such as the transaction waiting time distribution. Furthermore, we validate the model by comparing the results to values obtained from measurements in a closed lab environment based on the Ethereum blockchain.

  @inproceedings{info3-inproceedings-2019-19, abstract = {Blockchain and distributed ledger technologies have become more and more popular and widespread during recent years. After the initial hype about the technology and many cryptocurrency related use cases, the technology slowly starts to make its way into other domains like food tracking and document management. In order to further contribute to the search of what this technology can be used for, more detailed performance evaluations are required in order to investigate key performance indicators and general limits of the technology. To this end, we develop a discrete-time queueing model that allows a detailed evaluation of the characteristics of a blockchain system, such as the transaction waiting time distribution. Furthermore, we validate the model by comparing the results to values obtained from measurements in a closed lab environment based on the Ethereum blockchain.}, author = {Geissler, Stefan and Prantl, Thomas and Lange, Stanislav and Wamser, Florian and Hoßfeld, Tobias}, booktitle = {31st International Teletraffic Congress (ITC). , Budapest, Hungary}, keywords = {ngn}, month = 8, title = {Discrete-Time Analysis of the Blockchain Distributed Ledger Technology}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-19 %A Geissler, Stefan %A Prantl, Thomas %A Lange, Stanislav %A Wamser, Florian %A Hoßfeld, Tobias %B 31st International Teletraffic Congress (ITC). , Budapest, Hungary %D 2019 %T Discrete-Time Analysis of the Blockchain Distributed Ledger Technology %X Blockchain and distributed ledger technologies have become more and more popular and widespread during recent years. After the initial hype about the technology and many cryptocurrency related use cases, the technology slowly starts to make its way into other domains like food tracking and document management. In order to further contribute to the search of what this technology can be used for, more detailed performance evaluations are required in order to investigate key performance indicators and general limits of the technology. To this end, we develop a discrete-time queueing model that allows a detailed evaluation of the characteristics of a blockchain system, such as the transaction waiting time distribution. Furthermore, we validate the model by comparing the results to values obtained from measurements in a closed lab environment based on the Ethereum blockchain.
• I See What you See: Real Time Prediction of Video Quality from Encrypted Streaming Traffic Wassermann, Sarah; Seufert, Michael; Casas, Pedro; Li, Gang; Kuang, Li in 4th Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) (2019).
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  We address the problem of real-time QoE monitoring of HAS, from the ISP perspective, focusing in particular on videoresolution analysis. Given the wide adoption of end-to-end encryption, we resort to machine-learning models to predict different video resolution levels in a fine-grained scale, ranging from 144p to 1080p resolution, using as input only packet-level data. The proposed measurement system performs predictions in real time, during the course of an ongoing video-streaming session, with a time granularity as small as one second. We consider the particular case of YouTube video streaming. Empirical evaluations on a large and heterogeneous corpus of YouTube measurements demonstrate that the proposed system can predict video resolution with very high accuracy, and in real time. Different from state of the art, the prediction task is not bound to coarse-grained video quality classes and does not require chunk-detection approaches for feature extraction.

  @inproceedings{info3-inproceedings-2019-28, abstract = {We address the problem of real-time QoE monitoring of HAS, from the ISP perspective, focusing in particular on videoresolution analysis. Given the wide adoption of end-to-end encryption, we resort to machine-learning models to predict different video resolution levels in a fine-grained scale, ranging from 144p to 1080p resolution, using as input only packet-level data. The proposed measurement system performs predictions in real time, during the course of an ongoing video-streaming session, with a time granularity as small as one second. We consider the particular case of YouTube video streaming. Empirical evaluations on a large and heterogeneous corpus of YouTube measurements demonstrate that the proposed system can predict video resolution with very high accuracy, and in real time. Different from state of the art, the prediction task is not bound to coarse-grained video quality classes and does not require chunk-detection approaches for feature extraction.}, address = {Los Cabos, Mexico}, author = {Wassermann, Sarah and Seufert, Michael and Casas, Pedro and Li, Gang and Kuang, Li}, booktitle = {4th Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE)}, keywords = {ua-net}, month = 10, title = {I See What you See: Real Time Prediction of Video Quality from Encrypted Streaming Traffic}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-28 %A Wassermann, Sarah %A Seufert, Michael %A Casas, Pedro %A Li, Gang %A Kuang, Li %B 4th Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) %C Los Cabos, Mexico %D 2019 %T I See What you See: Real Time Prediction of Video Quality from Encrypted Streaming Traffic %X We address the problem of real-time QoE monitoring of HAS, from the ISP perspective, focusing in particular on videoresolution analysis. Given the wide adoption of end-to-end encryption, we resort to machine-learning models to predict different video resolution levels in a fine-grained scale, ranging from 144p to 1080p resolution, using as input only packet-level data. The proposed measurement system performs predictions in real time, during the course of an ongoing video-streaming session, with a time granularity as small as one second. We consider the particular case of YouTube video streaming. Empirical evaluations on a large and heterogeneous corpus of YouTube measurements demonstrate that the proposed system can predict video resolution with very high accuracy, and in real time. Different from state of the art, the prediction task is not bound to coarse-grained video quality classes and does not require chunk-detection approaches for feature extraction.
• Traffic Measurement Study on Video Streaming with the Amazon Echo Show Loh, Frank; Vomhoff, Viktoria; Wamser, Florian; Metzger, Florian; Hoßfeld, Tobias in 4th Internet-QoE Workshop: QoE-based Analysis and Management of Data Communication Networks (2019).
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  The Amazon Echo Show is one of the most widely used smart speakers with the ability to stream video. Due to its popularity, the traffc profiles of such devices are of interest to network operators and providers. This work presents a measurement study of the Amazon Echo Show in terms of network traffc and streaming behavior. More than 470 hours of streaming data are collected and analyzed at network layer. Based on this, streaming quality is derived at application layer. The study quantifies the traffc and shows that streaming with the Amazon Echo Show is comparable to streaming with a native web browser, but in a more conservative way.

  @inproceedings{info3-inproceedings-2019-26, abstract = {The Amazon Echo Show is one of the most widely used smart speakers with the ability to stream video. Due to its popularity, the traffc profiles of such devices are of interest to network operators and providers. This work presents a measurement study of the Amazon Echo Show in terms of network traffc and streaming behavior. More than 470 hours of streaming data are collected and analyzed at network layer. Based on this, streaming quality is derived at application layer. The study quantifies the traffc and shows that streaming with the Amazon Echo Show is comparable to streaming with a native web browser, but in a more conservative way.}, author = {Loh, Frank and Vomhoff, Viktoria and Wamser, Florian and Metzger, Florian and Hoßfeld, Tobias}, booktitle = {4th Internet-QoE Workshop: QoE-based Analysis and Management of Data Communication Networks}, keywords = {can}, month = 10, title = {Traffic Measurement Study on Video Streaming with the Amazon Echo Show}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-26 %A Loh, Frank %A Vomhoff, Viktoria %A Wamser, Florian %A Metzger, Florian %A Hoßfeld, Tobias %B 4th Internet-QoE Workshop: QoE-based Analysis and Management of Data Communication Networks %D 2019 %T Traffic Measurement Study on Video Streaming with the Amazon Echo Show %X The Amazon Echo Show is one of the most widely used smart speakers with the ability to stream video. Due to its popularity, the traffc profiles of such devices are of interest to network operators and providers. This work presents a measurement study of the Amazon Echo Show in terms of network traffc and streaming behavior. More than 470 hours of streaming data are collected and analyzed at network layer. Based on this, streaming quality is derived at application layer. The study quantifies the traffc and shows that streaming with the Amazon Echo Show is comparable to streaming with a native web browser, but in a more conservative way.
• On the Analysis of YouTube QoE in Cellular Networks through in-Smartphone Measurements Wassermann, Sarah; Casas, Pedro; Seufert, Michael; Wamser, Florian in 12th IFIP Wireless and Mobile Networking Conference (WMNC) (2019).
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  @inproceedings{info3-inproceedings-2019-18, address = {Paris, France}, author = {Wassermann, Sarah and Casas, Pedro and Seufert, Michael and Wamser, Florian}, booktitle = {12th IFIP Wireless and Mobile Networking Conference (WMNC)}, keywords = {ua-net}, month = 9, title = {On the Analysis of YouTube QoE in Cellular Networks through in-Smartphone Measurements}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-18 %A Wassermann, Sarah %A Casas, Pedro %A Seufert, Michael %A Wamser, Florian %B 12th IFIP Wireless and Mobile Networking Conference (WMNC) %C Paris, France %D 2019 %T On the Analysis of YouTube QoE in Cellular Networks through in-Smartphone Measurements
• Gray, Nicholas, et al. "Highlighting the Gap Between Expected and Actual Behavior in P4-enabled Networks Gray, Nicholas; Grigorjew, Alexej; Hoßfeld, Tobias; Shukla, Apoorv; Zinner, Thomas in IFIP/IEEE Symposium on Integrated Network and Service Management (IM) (2019).
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  Modern networks increasingly rely on Software-defined Networking (SDN) and Network Function Virtualization (NFV) to augment their flexibility in high load scenarios. To further enhance the performance, a part of the functionality is often offloaded to forwarding devices, which are used as hardware accelerators and are configured by high level programming languages such as P4. However, hardware vendors use sophisticated technologies to implement these standards, which need to be understood by the programmer to avoid unintended behavior. In this demonstration we highlight the severe consequences of only relying on the network programming language when ignoring the device-specific limitations. We show this by the example of a Denial of Service attack against a P4-enabled SmartNIC. Finally, we discuss possible mitigations to this attack and stress the importance of an overall understanding of the entire system.

  @inproceedings{info3-demo-2019-1, abstract = {Modern networks increasingly rely on Software-defined Networking (SDN) and Network Function Virtualization (NFV) to augment their flexibility in high load scenarios. To further enhance the performance, a part of the functionality is often offloaded to forwarding devices, which are used as hardware accelerators and are configured by high level programming languages such as P4. However, hardware vendors use sophisticated technologies to implement these standards, which need to be understood by the programmer to avoid unintended behavior. In this demonstration we highlight the severe consequences of only relying on the network programming language when ignoring the device-specific limitations. We show this by the example of a Denial of Service attack against a P4-enabled SmartNIC. Finally, we discuss possible mitigations to this attack and stress the importance of an overall understanding of the entire system.}, author = {Gray, Nicholas and Grigorjew, Alexej and Hoßfeld, Tobias and Shukla, Apoorv and Zinner, Thomas}, booktitle = {IFIP/IEEE Symposium on Integrated Network and Service Management (IM)}, keywords = {ngn}, month = 3, title = {Gray, Nicholas, et al. "Highlighting the Gap Between Expected and Actual Behavior in P4-enabled Networks}, year = 2019 }

  %0 Conference Paper %1 info3-demo-2019-1 %A Gray, Nicholas %A Grigorjew, Alexej %A Hoßfeld, Tobias %A Shukla, Apoorv %A Zinner, Thomas %B IFIP/IEEE Symposium on Integrated Network and Service Management (IM) %D 2019 %T Gray, Nicholas, et al. "Highlighting the Gap Between Expected and Actual Behavior in P4-enabled Networks %X Modern networks increasingly rely on Software-defined Networking (SDN) and Network Function Virtualization (NFV) to augment their flexibility in high load scenarios. To further enhance the performance, a part of the functionality is often offloaded to forwarding devices, which are used as hardware accelerators and are configured by high level programming languages such as P4. However, hardware vendors use sophisticated technologies to implement these standards, which need to be understood by the programmer to avoid unintended behavior. In this demonstration we highlight the severe consequences of only relying on the network programming language when ignoring the device-specific limitations. We show this by the example of a Denial of Service attack against a P4-enabled SmartNIC. Finally, we discuss possible mitigations to this attack and stress the importance of an overall understanding of the entire system.
• Crowd-based Assessment of Deformational Cranial Asymmetries Borchert, Kathrin; Hirth, Matthias; Stellzig-Eisenhauer, Angelika; Kunz, Felix in International Workshop on Crowd-Powered e-Services (CROPS) (2019).
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  @inproceedings{info3-inproceedings-2019-17, address = {Trondheim, Norway}, author = {Borchert, Kathrin and Hirth, Matthias and Stellzig-Eisenhauer, Angelika and Kunz, Felix}, booktitle = {International Workshop on Crowd-Powered e-Services (CROPS)}, keywords = {ua-net}, month = 9, title = {Crowd-based Assessment of Deformational Cranial Asymmetries}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-17 %A Borchert, Kathrin %A Hirth, Matthias %A Stellzig-Eisenhauer, Angelika %A Kunz, Felix %B International Workshop on Crowd-Powered e-Services (CROPS) %C Trondheim, Norway %D 2019 %T Crowd-based Assessment of Deformational Cranial Asymmetries
• Fundamental Advantages of Considering Quality of Experience Distributions over Mean Opinion Scores Seufert, Michael in 11th International Conference on Quality of Multimedia Experience (QoMEX) (2019).
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  @inproceedings{info3-inproceedings-2019-14, address = {Berlin, Germany}, author = {Seufert, Michael}, booktitle = {11th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ua-net}, month = 6, title = {Fundamental Advantages of Considering Quality of Experience Distributions over Mean Opinion Scores}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-14 %A Seufert, Michael %B 11th International Conference on Quality of Multimedia Experience (QoMEX) %C Berlin, Germany %D 2019 %T Fundamental Advantages of Considering Quality of Experience Distributions over Mean Opinion Scores
• Web Performance Pitfalls Enghardt, Theresa; Zinner, Thomas; Feldmann, Anja in Passive and Active Measurement Conference (PAM) (2019).
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  @inproceedings{info3-inproceedings-2019-1, author = {Enghardt, Theresa and Zinner, Thomas and Feldmann, Anja}, booktitle = {Passive and Active Measurement Conference (PAM)}, keywords = {sys:hidden:inproceedings}, month = 3, title = {Web Performance Pitfalls}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-1 %A Enghardt, Theresa %A Zinner, Thomas %A Feldmann, Anja %B Passive and Active Measurement Conference (PAM) %D 2019 %T Web Performance Pitfalls
• BBGDASH: A Max-Min Bounded Bitrate Guidance for SDN Enabled Adaptive Video Streaming Alissa, Ali; Bentalab, Abdelhak; Zinner, Thomas; Ghita, Bogdan; Mkwawa, Is-Haka in 22nd Conference on Innovation in Clouds, Internet and Networks and Workshops (ICIN (2019).
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  @inproceedings{info3-inproceedings-2019-2, author = {Alissa, Ali and Bentalab, Abdelhak and Zinner, Thomas and Ghita, Bogdan and Mkwawa, Is-Haka}, booktitle = {22nd Conference on Innovation in Clouds, Internet and Networks and Workshops (ICIN}, keywords = {sys:hidden:inproceedings}, month = 2, title = {BBGDASH: A Max-Min Bounded Bitrate Guidance for SDN Enabled Adaptive Video Streaming}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-2 %A Alissa, Ali %A Bentalab, Abdelhak %A Zinner, Thomas %A Ghita, Bogdan %A Mkwawa, Is-Haka %B 22nd Conference on Innovation in Clouds, Internet and Networks and Workshops (ICIN %D 2019 %T BBGDASH: A Max-Min Bounded Bitrate Guidance for SDN Enabled Adaptive Video Streaming
• Computing QoE-relevant Adaptive Video Streaming Metrics using Discrete-Time Analysis Schwarzmann, Susanna; Breitbach, Paula; Zinner, Thomas in Third International Workshop on Quality of Experience Management 2019 (2019).
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  @inproceedings{info3-inproceedings-2019-3, author = {Schwarzmann, Susanna and Breitbach, Paula and Zinner, Thomas}, booktitle = {Third International Workshop on Quality of Experience Management 2019}, keywords = {dfg-sdn}, month = 2, title = {Computing QoE-relevant Adaptive Video Streaming Metrics using Discrete-Time Analysis}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-3 %A Schwarzmann, Susanna %A Breitbach, Paula %A Zinner, Thomas %B Third International Workshop on Quality of Experience Management 2019 %D 2019 %T Computing QoE-relevant Adaptive Video Streaming Metrics using Discrete-Time Analysis
• Discrete-Time Modeling of NFV Accelerators that Exploit Batched Processing Lange, Stanislav; Linguaglossa, Leonardo; Geissler, Stefan; Rossi, Dario; Zinner, Thomas in IEEE Conference on Computer Communications (Infocom) (2019).
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  @inproceedings{info3-inproceedings-2019-4, author = {Lange, Stanislav and Linguaglossa, Leonardo and Geissler, Stefan and Rossi, Dario and Zinner, Thomas}, booktitle = {IEEE Conference on Computer Communications (Infocom)}, keywords = {5g-net}, month = 4, title = {Discrete-Time Modeling of NFV Accelerators that Exploit Batched Processing}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-4 %A Lange, Stanislav %A Linguaglossa, Leonardo %A Geissler, Stefan %A Rossi, Dario %A Zinner, Thomas %B IEEE Conference on Computer Communications (Infocom) %D 2019 %T Discrete-Time Modeling of NFV Accelerators that Exploit Batched Processing
• KOMon - Kernel-based Online Monitoring of VNF Packet Processing Times Geissler, Stefan; Lange, Stanislav; Wamser, Florian; Zinner, Thomas; Hoßfeld, Tobias in 2019 International Conference on Networked Systems (NetSys), Best Paper Award (2019).
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  @inproceedings{info3-inproceedings-2019-5, author = {Geissler, Stefan and Lange, Stanislav and Wamser, Florian and Zinner, Thomas and Hoßfeld, Tobias}, booktitle = {2019 International Conference on Networked Systems (NetSys), Best Paper Award}, keywords = {ngn}, month = 3, title = {KOMon - Kernel-based Online Monitoring of VNF Packet Processing Times}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-5 %A Geissler, Stefan %A Lange, Stanislav %A Wamser, Florian %A Zinner, Thomas %A Hoßfeld, Tobias %B 2019 International Conference on Networked Systems (NetSys), Best Paper Award %D 2019 %T KOMon - Kernel-based Online Monitoring of VNF Packet Processing Times
• QUICker or not? - an Empirical Analysis of QUIC vs TCP for Video Streaming QoE Provisioning Seufert, Michael; Schatz, Raimund; Wehner, Nikolas; Casas, Pedro in 3rd International Workshop on Quality of Experience Management (QoE-Management) (2019).
  • [ Abstract ]
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  The introduction of the QUIC (Quick UDP Internet Connections) transport protocol by Google aimed to improve the Quality of Experience (QoE) with web services compared to the prevailing Transport Control Protocol (TCP). Nowadays, QUIC has become the default protocol to communicate between the Google Chrome browser and Google servers and accounts for an increasing share of the Internet traffic. This work investigates whether the promised QoE benefits of QUIC are indeed noticeable for end users or not. A measurement study was conducted for YouTube video streaming in two mobile and two fixed access networks, in which a defined set of videos was streamed back-to-back with QUIC and TCP in randomized order. QoE factors of video streaming (such as initial delay, the visual quality of the video, and stalling) were compared statistically to find significant differences between the streaming over QUIC and the streaming over TCP. Surprisingly, no evidence for any QoE improvement of QUIC over TCP in the context of YouTube streaming could be found.

  @inproceedings{info3-inproceedings-2019-7, abstract = {The introduction of the QUIC (Quick UDP Internet Connections) transport protocol by Google aimed to improve the Quality of Experience (QoE) with web services compared to the prevailing Transport Control Protocol (TCP). Nowadays, QUIC has become the default protocol to communicate between the Google Chrome browser and Google servers and accounts for an increasing share of the Internet traffic. This work investigates whether the promised QoE benefits of QUIC are indeed noticeable for end users or not. A measurement study was conducted for YouTube video streaming in two mobile and two fixed access networks, in which a defined set of videos was streamed back-to-back with QUIC and TCP in randomized order. QoE factors of video streaming (such as initial delay, the visual quality of the video, and stalling) were compared statistically to find significant differences between the streaming over QUIC and the streaming over TCP. Surprisingly, no evidence for any QoE improvement of QUIC over TCP in the context of YouTube streaming could be found.}, address = {Paris, France}, author = {Seufert, Michael and Schatz, Raimund and Wehner, Nikolas and Casas, Pedro}, booktitle = {3rd International Workshop on Quality of Experience Management (QoE-Management)}, keywords = {ua-net}, month = 2, title = {QUICker or not? - an Empirical Analysis of QUIC vs TCP for Video Streaming QoE Provisioning}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-7 %A Seufert, Michael %A Schatz, Raimund %A Wehner, Nikolas %A Casas, Pedro %B 3rd International Workshop on Quality of Experience Management (QoE-Management) %C Paris, France %D 2019 %T QUICker or not? - an Empirical Analysis of QUIC vs TCP for Video Streaming QoE Provisioning %X The introduction of the QUIC (Quick UDP Internet Connections) transport protocol by Google aimed to improve the Quality of Experience (QoE) with web services compared to the prevailing Transport Control Protocol (TCP). Nowadays, QUIC has become the default protocol to communicate between the Google Chrome browser and Google servers and accounts for an increasing share of the Internet traffic. This work investigates whether the promised QoE benefits of QUIC are indeed noticeable for end users or not. A measurement study was conducted for YouTube video streaming in two mobile and two fixed access networks, in which a defined set of videos was streamed back-to-back with QUIC and TCP in randomized order. QoE factors of video streaming (such as initial delay, the visual quality of the video, and stalling) were compared statistically to find significant differences between the streaming over QUIC and the streaming over TCP. Surprisingly, no evidence for any QoE improvement of QUIC over TCP in the context of YouTube streaming could be found.
• Stream-based Machine Learning for Real-time QoE Analysis of Encrypted Video Streaming Traffic Seufert, Michael; Casas, Pedro; Wehner, Nikolas; Li, Gang; Kuang, Li in 3rd International Workshop on Quality of Experience Management (QoE-Management) (2019).
  • [ Abstract ]
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  As stalling is the worst Quality of Experience (QoE) degradation of HTTP adaptive video streaming (HAS), this work presents a stream-based machine learning approach, ViCrypt, which analyzes stalling of YouTube streaming sessions in real-time from encrypted network traffic. The video streaming session is subdivided into a stream of short time slots of 1 s length, while considering two additional macro windows each for the current streaming trend and the whole ongoing streaming session. Constant memory features are extracted from the encrypted network traffic in these three windows in a stream-based fashion, and fed into a random forest model, which predicts whether the current time slot contains stalling or not. The presented system can predict stalling with a very high accuracy and the finest granularity to date (1 s), and thus, can be used in networks for real-time QoE analysis from encrypted YouTube video streaming traffic. The independent predictions for each consecutive slot of a streaming session can further be aggregated to obtain stalling estimations for the whole session. Thereby, the proposed method allows to quantify the initial delay, as well as the overall number of stalling events and the stalling ratio, i.e., the ratio of total stalling time and total playback time.

  @inproceedings{info3-inproceedings-2019-8, abstract = {As stalling is the worst Quality of Experience (QoE) degradation of HTTP adaptive video streaming (HAS), this work presents a stream-based machine learning approach, ViCrypt, which analyzes stalling of YouTube streaming sessions in real-time from encrypted network traffic. The video streaming session is subdivided into a stream of short time slots of 1 s length, while considering two additional macro windows each for the current streaming trend and the whole ongoing streaming session. Constant memory features are extracted from the encrypted network traffic in these three windows in a stream-based fashion, and fed into a random forest model, which predicts whether the current time slot contains stalling or not. The presented system can predict stalling with a very high accuracy and the finest granularity to date (1 s), and thus, can be used in networks for real-time QoE analysis from encrypted YouTube video streaming traffic. The independent predictions for each consecutive slot of a streaming session can further be aggregated to obtain stalling estimations for the whole session. Thereby, the proposed method allows to quantify the initial delay, as well as the overall number of stalling events and the stalling ratio, i.e., the ratio of total stalling time and total playback time.}, address = {Paris, France}, author = {Seufert, Michael and Casas, Pedro and Wehner, Nikolas and Li, Gang and Kuang, Li}, booktitle = {3rd International Workshop on Quality of Experience Management (QoE-Management)}, keywords = {net-man}, month = 2, title = {Stream-based Machine Learning for Real-time QoE Analysis of Encrypted Video Streaming Traffic}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-8 %A Seufert, Michael %A Casas, Pedro %A Wehner, Nikolas %A Li, Gang %A Kuang, Li %B 3rd International Workshop on Quality of Experience Management (QoE-Management) %C Paris, France %D 2019 %T Stream-based Machine Learning for Real-time QoE Analysis of Encrypted Video Streaming Traffic %X As stalling is the worst Quality of Experience (QoE) degradation of HTTP adaptive video streaming (HAS), this work presents a stream-based machine learning approach, ViCrypt, which analyzes stalling of YouTube streaming sessions in real-time from encrypted network traffic. The video streaming session is subdivided into a stream of short time slots of 1 s length, while considering two additional macro windows each for the current streaming trend and the whole ongoing streaming session. Constant memory features are extracted from the encrypted network traffic in these three windows in a stream-based fashion, and fed into a random forest model, which predicts whether the current time slot contains stalling or not. The presented system can predict stalling with a very high accuracy and the finest granularity to date (1 s), and thus, can be used in networks for real-time QoE analysis from encrypted YouTube video streaming traffic. The independent predictions for each consecutive slot of a streaming session can further be aggregated to obtain stalling estimations for the whole session. Thereby, the proposed method allows to quantify the initial delay, as well as the overall number of stalling events and the stalling ratio, i.e., the ratio of total stalling time and total playback time.
• Peeking under the Hood – How the Measurement Setup Influences the Video Streaming Behavior Schwind, Anika; Janiak, Lea; Moldovan, Christian; Wamser, Florian; Hoßfeld, Tobias in The 3rd International Workshop on Quality of Experience Management (QoE-Management 2019) (2019).
  • [ Abstract ]
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  Global Internet video traffic will dramatically increase in the next years. With this rapid growth, interest in the application behavior of video streaming services and the resulting user experience rises. In particular, there is a need to understand the influence of system parameters on the streaming performance. Thus, several monitoring approaches have been developed which allow conducting automated measurements on a large-scale, for example, lightweight approaches for measurements running in the mobile networks or setups using a virtual frame buffer for servers without a display running in virtualized cloud environments. In some cases, the measurement hardware can totally be controlled, in other cases, there is no knowledge about parallel running services. In this paper, we answer the question whether and how much the measurement setup (e.g., virtualization, headless browsers, load on machines) influences the video streaming behavior. Therefore, we compare eight management setups with the ground truth (an end user watching a video on the own device) by evaluating the key performance indicators on application layer during video streaming, i.e. initial video playout delays and stalling. Our results reveal important insights: some of the common measurement setups heavily influence the measurements and must be avoided to collect reliable results.

  @inproceedings{info3-inproceedings-2019-6, abstract = {Global Internet video traffic will dramatically increase in the next years. With this rapid growth, interest in the application behavior of video streaming services and the resulting user experience rises. In particular, there is a need to understand the influence of system parameters on the streaming performance. Thus, several monitoring approaches have been developed which allow conducting automated measurements on a large-scale, for example, lightweight approaches for measurements running in the mobile networks or setups using a virtual frame buffer for servers without a display running in virtualized cloud environments. In some cases, the measurement hardware can totally be controlled, in other cases, there is no knowledge about parallel running services. In this paper, we answer the question whether and how much the measurement setup (e.g., virtualization, headless browsers, load on machines) influences the video streaming behavior. Therefore, we compare eight management setups with the ground truth (an end user watching a video on the own device) by evaluating the key performance indicators on application layer during video streaming, i.e. initial video playout delays and stalling. Our results reveal important insights: some of the common measurement setups heavily influence the measurements and must be avoided to collect reliable results.}, address = {Paris, France}, author = {Schwind, Anika and Janiak, Lea and Moldovan, Christian and Wamser, Florian and Hoßfeld, Tobias}, booktitle = {The 3rd International Workshop on Quality of Experience Management (QoE-Management 2019)}, keywords = {ua-net}, month = 2, title = {Peeking under the Hood – How the Measurement Setup Influences the Video Streaming Behavior}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-6 %A Schwind, Anika %A Janiak, Lea %A Moldovan, Christian %A Wamser, Florian %A Hoßfeld, Tobias %B The 3rd International Workshop on Quality of Experience Management (QoE-Management 2019) %C Paris, France %D 2019 %T Peeking under the Hood – How the Measurement Setup Influences the Video Streaming Behavior %X Global Internet video traffic will dramatically increase in the next years. With this rapid growth, interest in the application behavior of video streaming services and the resulting user experience rises. In particular, there is a need to understand the influence of system parameters on the streaming performance. Thus, several monitoring approaches have been developed which allow conducting automated measurements on a large-scale, for example, lightweight approaches for measurements running in the mobile networks or setups using a virtual frame buffer for servers without a display running in virtualized cloud environments. In some cases, the measurement hardware can totally be controlled, in other cases, there is no knowledge about parallel running services. In this paper, we answer the question whether and how much the measurement setup (e.g., virtualization, headless browsers, load on machines) influences the video streaming behavior. Therefore, we compare eight management setups with the ground truth (an end user watching a video on the own device) by evaluating the key performance indicators on application layer during video streaming, i.e. initial video playout delays and stalling. Our results reveal important insights: some of the common measurement setups heavily influence the measurements and must be avoided to collect reliable results.
• Energy-Efficient Adaptation Logic for HTTP Streaming in Mobile Networks Moldovan, Christian; Wamser, Florian; Hoßfeld, Tobias in 2019 International Conference on Networked Systems (NetSys) (2019).
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  The requirements for video streaming have changed drastically during the past years. In today's Internet, high definition resolutions are considered default for videos, even in mobile settings, and with 4G penetration reaching 90 percent in the US, this no longer poses a big problem. However, while mobile bandwidth has increased, the battery life time of mobile devices has not increased significantly. Furthermore, current data plans are still not large enough to regularly stream movies during the commute. Users still resort to downloading media before travel. In this paper we propose a new HTTP adaptive streaming algorithm that delivers videos in high quality while avoiding stalling events, schedules the download of video segments so that a energy conserving idle state is often reached and keeps the buffer low at points in the video where many viewers abandon the video to save data. While most adaptive streaming algorithms optimize quality and stalling, this is the first attempt to use an adaptive streaming algorithm to reduce energy consumption. Since video streaming providers mostly care about the Quality of Experience when watching videos, energy efficiency is left to the device manufacturers. Therefore, both parties have little incentive to cooperate in this regard. But on the Internet of tomorrow, where most videos are watched on mobile devices, energy efficiency and the Quality of Experience must go hand in hand.

  @inproceedings{info3-inproceedings-2019-9, abstract = {The requirements for video streaming have changed drastically during the past years. In today's Internet, high definition resolutions are considered default for videos, even in mobile settings, and with 4G penetration reaching 90 percent in the US, this no longer poses a big problem. However, while mobile bandwidth has increased, the battery life time of mobile devices has not increased significantly. Furthermore, current data plans are still not large enough to regularly stream movies during the commute. Users still resort to downloading media before travel. In this paper we propose a new HTTP adaptive streaming algorithm that delivers videos in high quality while avoiding stalling events, schedules the download of video segments so that a energy conserving idle state is often reached and keeps the buffer low at points in the video where many viewers abandon the video to save data. While most adaptive streaming algorithms optimize quality and stalling, this is the first attempt to use an adaptive streaming algorithm to reduce energy consumption. Since video streaming providers mostly care about the Quality of Experience when watching videos, energy efficiency is left to the device manufacturers. Therefore, both parties have little incentive to cooperate in this regard. But on the Internet of tomorrow, where most videos are watched on mobile devices, energy efficiency and the Quality of Experience must go hand in hand.}, author = {Moldovan, Christian and Wamser, Florian and Hoßfeld, Tobias}, booktitle = {2019 International Conference on Networked Systems (NetSys)}, keywords = {net-man}, month = 3, title = {Energy-Efficient Adaptation Logic for HTTP Streaming in Mobile Networks}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-9 %A Moldovan, Christian %A Wamser, Florian %A Hoßfeld, Tobias %B 2019 International Conference on Networked Systems (NetSys) %D 2019 %T Energy-Efficient Adaptation Logic for HTTP Streaming in Mobile Networks %X The requirements for video streaming have changed drastically during the past years. In today's Internet, high definition resolutions are considered default for videos, even in mobile settings, and with 4G penetration reaching 90 percent in the US, this no longer poses a big problem. However, while mobile bandwidth has increased, the battery life time of mobile devices has not increased significantly. Furthermore, current data plans are still not large enough to regularly stream movies during the commute. Users still resort to downloading media before travel. In this paper we propose a new HTTP adaptive streaming algorithm that delivers videos in high quality while avoiding stalling events, schedules the download of video segments so that a energy conserving idle state is often reached and keeps the buffer low at points in the video where many viewers abandon the video to save data. While most adaptive streaming algorithms optimize quality and stalling, this is the first attempt to use an adaptive streaming algorithm to reduce energy consumption. Since video streaming providers mostly care about the Quality of Experience when watching videos, energy efficiency is left to the device manufacturers. Therefore, both parties have little incentive to cooperate in this regard. But on the Internet of tomorrow, where most videos are watched on mobile devices, energy efficiency and the Quality of Experience must go hand in hand.
• In Vivo or in Vitro? Influence of the Study Design on Crowdsourced Video QoE Borchert, Kathrin; Schwind, Anika; Hirth, Matthias; Hoßfeld, Tobias in 11th International Conference on Quality of Multimedia Experience (QoMEX) (2019).
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  @inproceedings{info3-inproceedings-2019-10, author = {Borchert, Kathrin and Schwind, Anika and Hirth, Matthias and Hoßfeld, Tobias}, booktitle = {11th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ua-net}, month = 6, title = {In Vivo or in Vitro? Influence of the Study Design on Crowdsourced Video QoE}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-10 %A Borchert, Kathrin %A Schwind, Anika %A Hirth, Matthias %A Hoßfeld, Tobias %B 11th International Conference on Quality of Multimedia Experience (QoMEX) %D 2019 %T In Vivo or in Vitro? Influence of the Study Design on Crowdsourced Video QoE
• Features that Matter: Feature Selection for On-line Stalling Prediction in Encrypted Video Streaming Seufert, Michael; Casas, Pedro; Wehner, Nikolas; Li, Gang; Kuang, Li in 2nd International Workshop on Network Intelligence (NI) (2019).
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  @inproceedings{info3-inproceedings-2019-11, address = {Paris, France}, author = {Seufert, Michael and Casas, Pedro and Wehner, Nikolas and Li, Gang and Kuang, Li}, booktitle = {2nd International Workshop on Network Intelligence (NI)}, keywords = {net-man}, month = 4, title = {Features that Matter: Feature Selection for On-line Stalling Prediction in Encrypted Video Streaming}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-11 %A Seufert, Michael %A Casas, Pedro %A Wehner, Nikolas %A Li, Gang %A Kuang, Li %B 2nd International Workshop on Network Intelligence (NI) %C Paris, France %D 2019 %T Features that Matter: Feature Selection for On-line Stalling Prediction in Encrypted Video Streaming
• Online Detection of Stalling and Scrubbing in Adaptive Video Streaming Maggi, Lorenzo; Leguay, Jeremy; Seufert, Michael; Casas, Pedro in 17th International Symposium on Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks (WiOpt) (2019).
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  @inproceedings{info3-inproceedings-2019-12, address = {Avignon, France}, author = {Maggi, Lorenzo and Leguay, Jeremy and Seufert, Michael and Casas, Pedro}, booktitle = {17th International Symposium on Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks (WiOpt)}, keywords = {net-man}, month = 6, title = {Online Detection of Stalling and Scrubbing in Adaptive Video Streaming}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-12 %A Maggi, Lorenzo %A Leguay, Jeremy %A Seufert, Michael %A Casas, Pedro %B 17th International Symposium on Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks (WiOpt) %C Avignon, France %D 2019 %T Online Detection of Stalling and Scrubbing in Adaptive Video Streaming
• Is QUIC becoming the New TCP? On the Potential Impact of a New Protocol on Networked Multimedia QoE Seufert, Michael; Schatz, Raimund; Wehner, Nikolas; Gardlo, Bruno; Casas, Pedro in 11th International Conference on Quality of Multimedia Experience (QoMEX) (2019).
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  @inproceedings{info3-inproceedings-2019-13, address = {Berlin, Germany}, author = {Seufert, Michael and Schatz, Raimund and Wehner, Nikolas and Gardlo, Bruno and Casas, Pedro}, booktitle = {11th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ua-net}, month = 6, title = {Is QUIC becoming the New TCP? On the Potential Impact of a New Protocol on Networked Multimedia QoE}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-13 %A Seufert, Michael %A Schatz, Raimund %A Wehner, Nikolas %A Gardlo, Bruno %A Casas, Pedro %B 11th International Conference on Quality of Multimedia Experience (QoMEX) %C Berlin, Germany %D 2019 %T Is QUIC becoming the New TCP? On the Potential Impact of a New Protocol on Networked Multimedia QoE
• Task Scheduling on Crowdsourcing Platforms for Enabling Completion Time SLAs Hirth, Matthias; Steurer, Florian; Borchert, Kathrin; Dubiner, Dan in 31st International Teletraffic Congress (ITC) (2019).
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  @inproceedings{info3-inproceedings-2019-20, address = {Budapest, Hungary}, author = {Hirth, Matthias and Steurer, Florian and Borchert, Kathrin and Dubiner, Dan}, booktitle = {31st International Teletraffic Congress (ITC)}, keywords = {ua-net}, month = 8, title = {Task Scheduling on Crowdsourcing Platforms for Enabling Completion Time SLAs}, year = 2019 }

  %0 Conference Paper %1 info3-inproceedings-2019-20 %A Hirth, Matthias %A Steurer, Florian %A Borchert, Kathrin %A Dubiner, Dan %B 31st International Teletraffic Congress (ITC) %C Budapest, Hungary %D 2019 %T Task Scheduling on Crowdsourcing Platforms for Enabling Completion Time SLAs

• Pervasive Communities in the Internet of People Lagerspetz, Eemil; Flores, Huber; Mäkitalo, Niko; Hui, Pan; Nurmi, Petteri; Tarkoma, Sasu; Passarella, Andrea; Ott, Jörg; Reichl, Peter; Conti, Marco; Fiedler, Markus; Singh, Jatinder; Strufe, Thorsten; Hoßfeld, Tobias in Proceedings of the 1st International Workshop on Context-Awareness for Multi-Device Pervasive and Mobile Computing (PerCrowd) (2018).
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  @inproceedings{info3-inproceedings-2018-5, address = {Athens, Greece}, author = {Lagerspetz, Eemil and Flores, Huber and Mäkitalo, Niko and Hui, Pan and Nurmi, Petteri and Tarkoma, Sasu and Passarella, Andrea and Ott, Jörg and Reichl, Peter and Conti, Marco and Fiedler, Markus and Singh, Jatinder and Strufe, Thorsten and Hoßfeld, Tobias}, booktitle = {Proceedings of the 1st International Workshop on Context-Awareness for Multi-Device Pervasive and Mobile Computing (PerCrowd)}, keywords = {sys:hidden:inproceedings}, month = 3, title = {Pervasive Communities in the Internet of People}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-5 %A Lagerspetz, Eemil %A Flores, Huber %A Mäkitalo, Niko %A Hui, Pan %A Nurmi, Petteri %A Tarkoma, Sasu %A Passarella, Andrea %A Ott, Jörg %A Reichl, Peter %A Conti, Marco %A Fiedler, Markus %A Singh, Jatinder %A Strufe, Thorsten %A Hoßfeld, Tobias %B Proceedings of the 1st International Workshop on Context-Awareness for Multi-Device Pervasive and Mobile Computing (PerCrowd) %C Athens, Greece %D 2018 %T Pervasive Communities in the Internet of People
• Studying the Impact of HAS QoE Factors on the Standardized QoE Model P.1203 Seufert, Michael; Wehner, Nikolas; Casas, Pedro in 3rd Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) (2018).
  • [ Abstract ]
  • [ BibTeX ]
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  P.1203 is a recent standardized model for assessing the Quality of Experience (QoE) of HTTP Adaptive Video Streaming (HAS). However, its complex definition does not allow for a straightforward identification of the underlying assumptions. To overcome this issue, this work investigates the impact of the well-known QoE factors of HAS, namely, initial delay, stalling, and adaptation, on the output QoE score of the model. Therefore, parameter studies are conducted using a reference implementation of P.1203, and the model response to variations of the input QoE factors are compared to results of previous QoE studies in order to get a deeper understanding of the standardized model and its inherent weighting of the QoE factors of HAS.

  @inproceedings{info3-inproceedings-2018-44, abstract = {P.1203 is a recent standardized model for assessing the Quality of Experience (QoE) of HTTP Adaptive Video Streaming (HAS). However, its complex definition does not allow for a straightforward identification of the underlying assumptions. To overcome this issue, this work investigates the impact of the well-known QoE factors of HAS, namely, initial delay, stalling, and adaptation, on the output QoE score of the model. Therefore, parameter studies are conducted using a reference implementation of P.1203, and the model response to variations of the input QoE factors are compared to results of previous QoE studies in order to get a deeper understanding of the standardized model and its inherent weighting of the QoE factors of HAS.}, address = {Vienna, Austria}, author = {Seufert, Michael and Wehner, Nikolas and Casas, Pedro}, booktitle = {3rd Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE)}, keywords = {sys:hidden:inproceedings}, month = 7, title = {Studying the Impact of HAS QoE Factors on the Standardized QoE Model P.1203}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-44 %A Seufert, Michael %A Wehner, Nikolas %A Casas, Pedro %B 3rd Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) %C Vienna, Austria %D 2018 %T Studying the Impact of HAS QoE Factors on the Standardized QoE Model P.1203 %X P.1203 is a recent standardized model for assessing the Quality of Experience (QoE) of HTTP Adaptive Video Streaming (HAS). However, its complex definition does not allow for a straightforward identification of the underlying assumptions. To overcome this issue, this work investigates the impact of the well-known QoE factors of HAS, namely, initial delay, stalling, and adaptation, on the output QoE score of the model. Therefore, parameter studies are conducted using a reference implementation of P.1203, and the model response to variations of the input QoE factors are compared to results of previous QoE studies in order to get a deeper understanding of the standardized model and its inherent weighting of the QoE factors of HAS.
• Investigating the Impact of Advertisement Banners and Clips on Video QoE Zach, Ondrej; Slanina, Martin; Seufert, Michael in 3rd Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) (2018).
  • [ Abstract ]
  • [ BibTeX ]
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  Although Quality of Experience (QoE) of Internet services can be affected by context influence factors, their actual impact is not widely investigated yet. In the context of online video services, web portals often display advertisement banners or clips to monetize their service. However, these advertisements can distract or annoy the users, which might degrade the QoE of the actual video service. In this work, two crowdsourcing studies were conducted to investigate the impact of advertisement banners and clips on video QoE. Therefore, both theoretical opinions on in-service advertisements and subjective quality ratings are evaluated. The findings confirm that advertisements are negatively perceived by users during service consumption, but a generally negative impact on video QoE cannot be supported, as the interplay of advertisement and the QoE of video services is rather complex.

  @inproceedings{info3-inproceedings-2018-43, abstract = {Although Quality of Experience (QoE) of Internet services can be affected by context influence factors, their actual impact is not widely investigated yet. In the context of online video services, web portals often display advertisement banners or clips to monetize their service. However, these advertisements can distract or annoy the users, which might degrade the QoE of the actual video service. In this work, two crowdsourcing studies were conducted to investigate the impact of advertisement banners and clips on video QoE. Therefore, both theoretical opinions on in-service advertisements and subjective quality ratings are evaluated. The findings confirm that advertisements are negatively perceived by users during service consumption, but a generally negative impact on video QoE cannot be supported, as the interplay of advertisement and the QoE of video services is rather complex.}, address = {Vienna, Austria}, author = {Zach, Ondrej and Slanina, Martin and Seufert, Michael}, booktitle = {3rd Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE)}, keywords = {sys:hidden:inproceedings}, month = 7, title = {Investigating the Impact of Advertisement Banners and Clips on Video QoE}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-43 %A Zach, Ondrej %A Slanina, Martin %A Seufert, Michael %B 3rd Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) %C Vienna, Austria %D 2018 %T Investigating the Impact of Advertisement Banners and Clips on Video QoE %X Although Quality of Experience (QoE) of Internet services can be affected by context influence factors, their actual impact is not widely investigated yet. In the context of online video services, web portals often display advertisement banners or clips to monetize their service. However, these advertisements can distract or annoy the users, which might degrade the QoE of the actual video service. In this work, two crowdsourcing studies were conducted to investigate the impact of advertisement banners and clips on video QoE. Therefore, both theoretical opinions on in-service advertisements and subjective quality ratings are evaluated. The findings confirm that advertisements are negatively perceived by users during service consumption, but a generally negative impact on video QoE cannot be supported, as the interplay of advertisement and the QoE of video services is rather complex.
• Potential Traffic Savings by Leveraging Proximity of Communication Groups in Mobile Messaging Seufert, Michael; Schwind, Anika; Waigand, Marco; Hoßfeld, Tobias in 14th International Conference on Network and Service Management (CNSM) (2018).
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  Communication groups in mobile messaging applications (MMAs) multiply the data transmissions, because every message has to be delivered to all members of the communication group. Thereby, they put a high load on mobile networks. As the number of recipients is still comparably small, the dataintensive user-generated content cannot be handled efficiently in large content delivery networks. However, small communication groups, such as groups of friends or teams, might often be in close proximity, which can be leveraged to locally deliver messages by applying edge caching or device-to-device (D2D) communication. In this work, a simulation study is conducted to investigate these potential traffic savings in the mobile network. It is based on a realistic communication model of the MMA WhatsApp and utilizes different models for human mobility. The user mobility and MMA communication are simulated for a single day in a small city to obtain the ratio of messages, which could be potentially transmitted locally when utilizing edge caching and D2D communication.

  @inproceedings{info3-inproceedings-2018-40, abstract = {Communication groups in mobile messaging applications (MMAs) multiply the data transmissions, because every message has to be delivered to all members of the communication group. Thereby, they put a high load on mobile networks. As the number of recipients is still comparably small, the dataintensive user-generated content cannot be handled efficiently in large content delivery networks. However, small communication groups, such as groups of friends or teams, might often be in close proximity, which can be leveraged to locally deliver messages by applying edge caching or device-to-device (D2D) communication. In this work, a simulation study is conducted to investigate these potential traffic savings in the mobile network. It is based on a realistic communication model of the MMA WhatsApp and utilizes different models for human mobility. The user mobility and MMA communication are simulated for a single day in a small city to obtain the ratio of messages, which could be potentially transmitted locally when utilizing edge caching and D2D communication.}, address = {Rome, Italy}, author = {Seufert, Michael and Schwind, Anika and Waigand, Marco and Hoßfeld, Tobias}, booktitle = {14th International Conference on Network and Service Management (CNSM)}, keywords = {SoNetAn}, month = 11, title = {Potential Traffic Savings by Leveraging Proximity of Communication Groups in Mobile Messaging}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-40 %A Seufert, Michael %A Schwind, Anika %A Waigand, Marco %A Hoßfeld, Tobias %B 14th International Conference on Network and Service Management (CNSM) %C Rome, Italy %D 2018 %T Potential Traffic Savings by Leveraging Proximity of Communication Groups in Mobile Messaging %X Communication groups in mobile messaging applications (MMAs) multiply the data transmissions, because every message has to be delivered to all members of the communication group. Thereby, they put a high load on mobile networks. As the number of recipients is still comparably small, the dataintensive user-generated content cannot be handled efficiently in large content delivery networks. However, small communication groups, such as groups of friends or teams, might often be in close proximity, which can be leveraged to locally deliver messages by applying edge caching or device-to-device (D2D) communication. In this work, a simulation study is conducted to investigate these potential traffic savings in the mobile network. It is based on a realistic communication model of the MMA WhatsApp and utilizes different models for human mobility. The user mobility and MMA communication are simulated for a single day in a small city to obtain the ratio of messages, which could be potentially transmitted locally when utilizing edge caching and D2D communication.
• Addressing Shortcomings of Existing DDoS Protection Software Using Software-Defined Networking Iffländer, Lukas; Geissler, Stefan; Walter, Jürgen; Beierlieb, Lukas; Kounev, Samuel in 9th Symposium on Software Performance 2018 (SSP’18) (2018).
  • [ Abstract ]
  • [ BibTeX ]
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  DDoS attacks are becoming increasingly frequent and violent. A typical type of attack is the TCP SYN flood, inhibiting a server from opening new TCP connections. Current countermeasures to this attack introduce inefficiencies by either reducing computing resources on the service host or creating new network bottlenecks. In this work, we present a novel approach to mitigate TCP SYN flood attacks using software-defined networking. We perform an initial evaluation of a proof-of-concept implementation that exhibits performance measures close to existing countermeasures while circumventing their inefficiencies.

  @inproceedings{info3-article-2018-7, abstract = {DDoS attacks are becoming increasingly frequent and violent. A typical type of attack is the TCP SYN flood, inhibiting a server from opening new TCP connections. Current countermeasures to this attack introduce inefficiencies by either reducing computing resources on the service host or creating new network bottlenecks. In this work, we present a novel approach to mitigate TCP SYN flood attacks using software-defined networking. We perform an initial evaluation of a proof-of-concept implementation that exhibits performance measures close to existing countermeasures while circumventing their inefficiencies.}, address = {Hildesheim, Germany}, author = {Iffländer, Lukas and Geissler, Stefan and Walter, Jürgen and Beierlieb, Lukas and Kounev, Samuel}, booktitle = {9th Symposium on Software Performance 2018 (SSP'18)}, keywords = {ngn}, month = 10, title = {Addressing Shortcomings of Existing DDoS Protection Software Using Software-Defined Networking}, year = 2018 }

  %0 Conference Paper %1 info3-article-2018-7 %A Iffländer, Lukas %A Geissler, Stefan %A Walter, Jürgen %A Beierlieb, Lukas %A Kounev, Samuel %B 9th Symposium on Software Performance 2018 (SSP'18) %C Hildesheim, Germany %D 2018 %T Addressing Shortcomings of Existing DDoS Protection Software Using Software-Defined Networking %X DDoS attacks are becoming increasingly frequent and violent. A typical type of attack is the TCP SYN flood, inhibiting a server from opening new TCP connections. Current countermeasures to this attack introduce inefficiencies by either reducing computing resources on the service host or creating new network bottlenecks. In this work, we present a novel approach to mitigate TCP SYN flood attacks using software-defined networking. We perform an initial evaluation of a proof-of-concept implementation that exhibits performance measures close to existing countermeasures while circumventing their inefficiencies.
• Benchmarking the ONOS Controller with OFCProbe Nguyen-Ngoc, Anh; Raffeck, Simon; Lange, Stanislav; Geissler, Stefan; Zinner, Thomas; Tran-Gia, Phuoc in 7th International Conference on Communications and Electronics (ICCE) (2018).
  • [ Abstract ]
  • [ BibTeX ]
  • [ EndNote ]
  The increased popularity of Software Defined Networking (SDN) drives the development and research of all involved components. In particular, state-of-the-art SDN controllers are a central part of the resulting network architecture and have a large impact on the performance of the entire network. Hence, it is necessary to quantify various performance indicators of the SDN controller in order to assess its feasibility in the context of different network characteristics such as topology and network size w.r.t. the number of nodes and links. To this end, we extend the open-source controller benchmarking tool OFCProbe with several novel modules that are capable of recording relevant performance metrics and demonstrate their use in the context of benchmarking the ONOS controller. Furthermore, we investigate the impact of different types of topology characteristics on the performance of the controller. In this work, we focus on several performance indicators for SDN controllers. First, the time that the ONOS controller needs to discover the network topology and update its internal representation of the topology. Second, we investigate the duration of the installation of flow rules that are used for reactive path provisioning. Finally, we measure the response time of the controller when dealing with asynchronous messages.

  @inproceedings{info3-inproceedings-2018-15, abstract = {The increased popularity of Software Defined Networking (SDN) drives the development and research of all involved components. In particular, state-of-the-art SDN controllers are a central part of the resulting network architecture and have a large impact on the performance of the entire network. Hence, it is necessary to quantify various performance indicators of the SDN controller in order to assess its feasibility in the context of different network characteristics such as topology and network size w.r.t. the number of nodes and links. To this end, we extend the open-source controller benchmarking tool OFCProbe with several novel modules that are capable of recording relevant performance metrics and demonstrate their use in the context of benchmarking the ONOS controller. Furthermore, we investigate the impact of different types of topology characteristics on the performance of the controller. In this work, we focus on several performance indicators for SDN controllers. First, the time that the ONOS controller needs to discover the network topology and update its internal representation of the topology. Second, we investigate the duration of the installation of flow rules that are used for reactive path provisioning. Finally, we measure the response time of the controller when dealing with asynchronous messages.}, address = {Hue, Vietnam}, author = {Nguyen-Ngoc, Anh and Raffeck, Simon and Lange, Stanislav and Geissler, Stefan and Zinner, Thomas and Tran-Gia, Phuoc}, booktitle = {7th International Conference on Communications and Electronics (ICCE)}, keywords = {ngn}, month = 7, title = {Benchmarking the ONOS Controller with OFCProbe}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-15 %A Nguyen-Ngoc, Anh %A Raffeck, Simon %A Lange, Stanislav %A Geissler, Stefan %A Zinner, Thomas %A Tran-Gia, Phuoc %B 7th International Conference on Communications and Electronics (ICCE) %C Hue, Vietnam %D 2018 %T Benchmarking the ONOS Controller with OFCProbe %X The increased popularity of Software Defined Networking (SDN) drives the development and research of all involved components. In particular, state-of-the-art SDN controllers are a central part of the resulting network architecture and have a large impact on the performance of the entire network. Hence, it is necessary to quantify various performance indicators of the SDN controller in order to assess its feasibility in the context of different network characteristics such as topology and network size w.r.t. the number of nodes and links. To this end, we extend the open-source controller benchmarking tool OFCProbe with several novel modules that are capable of recording relevant performance metrics and demonstrate their use in the context of benchmarking the ONOS controller. Furthermore, we investigate the impact of different types of topology characteristics on the performance of the controller. In this work, we focus on several performance indicators for SDN controllers. First, the time that the ONOS controller needs to discover the network topology and update its internal representation of the topology. Second, we investigate the duration of the installation of flow rules that are used for reactive path provisioning. Finally, we measure the response time of the controller when dealing with asynchronous messages.
• Machine Learning Models for YouTube QoE and User Engagement Prediction in Smartphones Wassermann, Sarah; Wehner, Nikolas; Casas, Pedro in WAIN - Workshop on AI in Networks and Distributed Systems (2018).
  • [ Abstract ]
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  Measuring and monitoring YouTube Quality of Experience is a challenging task, especially when dealing with cellular networks and smartphone users. Using a large-scale database of crowdsourced YouTube-QoE measurements in smartphones, we conceive multiple machine-learning models to infer different YouTube-QoE-relevant metrics and userbehavior- related metrics from network-level measurements, without requiring root access to the smartphone, video-player embedding, or any other reverse-engineering-like approaches. The dataset includes measurements from more than 360 users worldwide, spanning over the last five years. Our preliminary results suggest that QoE-based monitoring of YouTube mobile can be realized through machine learning models with high accuracy, relying only on network-related features and without accessing any higher-layer metric to perform the estimations.

  @inproceedings{info3-inproceedings-2018-54, abstract = {Measuring and monitoring YouTube Quality of Experience is a challenging task, especially when dealing with cellular networks and smartphone users. Using a large-scale database of crowdsourced YouTube-QoE measurements in smartphones, we conceive multiple machine-learning models to infer different YouTube-QoE-relevant metrics and userbehavior- related metrics from network-level measurements, without requiring root access to the smartphone, video-player embedding, or any other reverse-engineering-like approaches. The dataset includes measurements from more than 360 users worldwide, spanning over the last five years. Our preliminary results suggest that QoE-based monitoring of YouTube mobile can be realized through machine learning models with high accuracy, relying only on network-related features and without accessing any higher-layer metric to perform the estimations.}, address = {Toulouse, France}, author = {Wassermann, Sarah and Wehner, Nikolas and Casas, Pedro}, booktitle = {WAIN - Workshop on AI in Networks and Distributed Systems}, keywords = {old}, month = 11, title = {Machine Learning Models for YouTube QoE and User Engagement Prediction in Smartphones}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-54 %A Wassermann, Sarah %A Wehner, Nikolas %A Casas, Pedro %B WAIN - Workshop on AI in Networks and Distributed Systems %C Toulouse, France %D 2018 %T Machine Learning Models for YouTube QoE and User Engagement Prediction in Smartphones %X Measuring and monitoring YouTube Quality of Experience is a challenging task, especially when dealing with cellular networks and smartphone users. Using a large-scale database of crowdsourced YouTube-QoE measurements in smartphones, we conceive multiple machine-learning models to infer different YouTube-QoE-relevant metrics and userbehavior- related metrics from network-level measurements, without requiring root access to the smartphone, video-player embedding, or any other reverse-engineering-like approaches. The dataset includes measurements from more than 360 users worldwide, spanning over the last five years. Our preliminary results suggest that QoE-based monitoring of YouTube mobile can be realized through machine learning models with high accuracy, relying only on network-related features and without accessing any higher-layer metric to perform the estimations.
• A Public Dataset for YouTube’s Mobile Streaming Client Karagkioules, Theodoros; Tsilimantos, Dimitrios; Valentin, Stefan; Wamser, Florian; Zeidler, Bernd; Seufert, Michael; Loh, Frank; Tran-Gia, Phuoc in Network Traffic Measurement and Analysis Conference (TMA) (2018).
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  @inproceedings{info3-inproceedings-2018-41, address = {Vienna, Austria}, author = {Karagkioules, Theodoros and Tsilimantos, Dimitrios and Valentin, Stefan and Wamser, Florian and Zeidler, Bernd and Seufert, Michael and Loh, Frank and Tran-Gia, Phuoc}, booktitle = {Network Traffic Measurement and Analysis Conference (TMA)}, keywords = {can}, title = {A Public Dataset for YouTube’s Mobile Streaming Client}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-41 %A Karagkioules, Theodoros %A Tsilimantos, Dimitrios %A Valentin, Stefan %A Wamser, Florian %A Zeidler, Bernd %A Seufert, Michael %A Loh, Frank %A Tran-Gia, Phuoc %B Network Traffic Measurement and Analysis Conference (TMA) %C Vienna, Austria %D 2018 %T A Public Dataset for YouTube’s Mobile Streaming Client
• Quality of Experience and Access Network Traffic Management of HTTP Adaptive Video Streaming Seufert, Michael; Tran-Gia, Phuoc in IEEE/IFIP Network Operations and Management Symposium (NOMS), Best Dissertation Award (2018).
  • [ Abstract ]
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  The thesis focuses on Quality of Experience (QoE) of HTTP adaptive video streaming (HAS) and traffic management in access networks to improve the QoE of HAS. First, the QoE impact of adaptation parameters and time on layer was investigated with subjective crowdsourcing studies. The results were used to compute a QoE-optimal adaptation strategy for given video and network conditions. This allows video service providers to develop and benchmark improved adaptation logics for HAS. Furthermore, the thesis investigated concepts to monitor video QoE on application and network layer, which can be used by network providers in the QoE-aware traffic management cycle. Moreover, an analytic and simulative performance evaluation of QoE-aware traffic management on a bottleneck link was conducted. Finally, the thesis investigated socially-aware traffic management for HAS via Wi-Fi offloading of mobile HAS flows. A model for the distribution of public Wi-Fi hotspots and a platform for socially-aware traffic management on private home routers was presented. A simulative performance evaluation investigated the impact of Wi-Fi offloading on the QoE and energy consumption of mobile HAS.

  @inproceedings{info3-inproceedings-2018-42, abstract = {The thesis focuses on Quality of Experience (QoE) of HTTP adaptive video streaming (HAS) and traffic management in access networks to improve the QoE of HAS. First, the QoE impact of adaptation parameters and time on layer was investigated with subjective crowdsourcing studies. The results were used to compute a QoE-optimal adaptation strategy for given video and network conditions. This allows video service providers to develop and benchmark improved adaptation logics for HAS. Furthermore, the thesis investigated concepts to monitor video QoE on application and network layer, which can be used by network providers in the QoE-aware traffic management cycle. Moreover, an analytic and simulative performance evaluation of QoE-aware traffic management on a bottleneck link was conducted. Finally, the thesis investigated socially-aware traffic management for HAS via Wi-Fi offloading of mobile HAS flows. A model for the distribution of public Wi-Fi hotspots and a platform for socially-aware traffic management on private home routers was presented. A simulative performance evaluation investigated the impact of Wi-Fi offloading on the QoE and energy consumption of mobile HAS.}, address = {Taipei, Taiwan}, author = {Seufert, Michael and Tran-Gia, Phuoc}, booktitle = {IEEE/IFIP Network Operations and Management Symposium (NOMS), Best Dissertation Award}, keywords = {sys:hidden:inproceedings}, month = 4, title = {Quality of Experience and Access Network Traffic Management of HTTP Adaptive Video Streaming}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-42 %A Seufert, Michael %A Tran-Gia, Phuoc %B IEEE/IFIP Network Operations and Management Symposium (NOMS), Best Dissertation Award %C Taipei, Taiwan %D 2018 %T Quality of Experience and Access Network Traffic Management of HTTP Adaptive Video Streaming %X The thesis focuses on Quality of Experience (QoE) of HTTP adaptive video streaming (HAS) and traffic management in access networks to improve the QoE of HAS. First, the QoE impact of adaptation parameters and time on layer was investigated with subjective crowdsourcing studies. The results were used to compute a QoE-optimal adaptation strategy for given video and network conditions. This allows video service providers to develop and benchmark improved adaptation logics for HAS. Furthermore, the thesis investigated concepts to monitor video QoE on application and network layer, which can be used by network providers in the QoE-aware traffic management cycle. Moreover, an analytic and simulative performance evaluation of QoE-aware traffic management on a bottleneck link was conducted. Finally, the thesis investigated socially-aware traffic management for HAS via Wi-Fi offloading of mobile HAS flows. A model for the distribution of public Wi-Fi hotspots and a platform for socially-aware traffic management on private home routers was presented. A simulative performance evaluation investigated the impact of Wi-Fi offloading on the QoE and energy consumption of mobile HAS.
• A Fair Share for All: Novel Adaptation Logic for QoE Fairness of HTTP Adaptive Video Streaming Seufert, Michael; Wehner, Nikolas; Casas, Pedro; Wamser, Florian in 14th International Conference on Network and Service Management (CNSM), Best Paper Award (2018).
  • [ Abstract ]
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  This paper presents a novel adaptation logic for HTTP adaptive streaming (HAS), which achieves not only a high Quality of Experience (QoE) but also high QoE fairness among independent and heterogeneous clients. The algorithm forces video clients to adapt the requested quality level based on the current network conditions and their individual bit rate requirements, such that the overall quality levels selected by all currently active streaming clients are fairly distributed, i.e., they do not diverge too much. The design of the algorithm is inspired by the well-known Transmission Control Protocol (TCP) congestion control, and drives heterogeneous clients to independently converge on similar quality levels without the need for communicating with each other and/or with a centralized controller in the network. By defining quality levels with equal visual quality, and preparing video representations accordingly, the quality level fairness is extended to QoE fairness. In this work, the design of the algorithm is described and a simulative performance evaluation is conducted to compare the QoE and QoE fairness of the proposed algorithm with other HAS adaptation logics.

  @inproceedings{info3-inproceedings-2018-38, abstract = {This paper presents a novel adaptation logic for HTTP adaptive streaming (HAS), which achieves not only a high Quality of Experience (QoE) but also high QoE fairness among independent and heterogeneous clients. The algorithm forces video clients to adapt the requested quality level based on the current network conditions and their individual bit rate requirements, such that the overall quality levels selected by all currently active streaming clients are fairly distributed, i.e., they do not diverge too much. The design of the algorithm is inspired by the well-known Transmission Control Protocol (TCP) congestion control, and drives heterogeneous clients to independently converge on similar quality levels without the need for communicating with each other and/or with a centralized controller in the network. By defining quality levels with equal visual quality, and preparing video representations accordingly, the quality level fairness is extended to QoE fairness. In this work, the design of the algorithm is described and a simulative performance evaluation is conducted to compare the QoE and QoE fairness of the proposed algorithm with other HAS adaptation logics.}, address = {Rome, Italy}, author = {Seufert, Michael and Wehner, Nikolas and Casas, Pedro and Wamser, Florian}, booktitle = {14th International Conference on Network and Service Management (CNSM), Best Paper Award}, keywords = {can}, month = 11, title = {A Fair Share for All: Novel Adaptation Logic for QoE Fairness of HTTP Adaptive Video Streaming}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-38 %A Seufert, Michael %A Wehner, Nikolas %A Casas, Pedro %A Wamser, Florian %B 14th International Conference on Network and Service Management (CNSM), Best Paper Award %C Rome, Italy %D 2018 %T A Fair Share for All: Novel Adaptation Logic for QoE Fairness of HTTP Adaptive Video Streaming %X This paper presents a novel adaptation logic for HTTP adaptive streaming (HAS), which achieves not only a high Quality of Experience (QoE) but also high QoE fairness among independent and heterogeneous clients. The algorithm forces video clients to adapt the requested quality level based on the current network conditions and their individual bit rate requirements, such that the overall quality levels selected by all currently active streaming clients are fairly distributed, i.e., they do not diverge too much. The design of the algorithm is inspired by the well-known Transmission Control Protocol (TCP) congestion control, and drives heterogeneous clients to independently converge on similar quality levels without the need for communicating with each other and/or with a centralized controller in the network. By defining quality levels with equal visual quality, and preparing video representations accordingly, the quality level fairness is extended to QoE fairness. In this work, the design of the algorithm is described and a simulative performance evaluation is conducted to compare the QoE and QoE fairness of the proposed algorithm with other HAS adaptation logics.
• Speed Index: Relating the Industrial Standard for User Perceived Web Performance to Web QoE Hoßfeld, Tobias; Metzger, Florian; Rossi, Dario in Proceedings of the 10th International Conference on Quality of Multimedia Experience (QoMEX 2018) (2018).
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  @inproceedings{info3-inproceedings-2018-9, address = {Sardinia, Italy}, author = {Hoßfeld, Tobias and Metzger, Florian and Rossi, Dario}, booktitle = {Proceedings of the 10th International Conference on Quality of Multimedia Experience (QoMEX 2018)}, keywords = {fullstack}, month = 5, title = {Speed Index: Relating the Industrial Standard for User Perceived Web Performance to Web QoE}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-9 %A Hoßfeld, Tobias %A Metzger, Florian %A Rossi, Dario %B Proceedings of the 10th International Conference on Quality of Multimedia Experience (QoMEX 2018) %C Sardinia, Italy %D 2018 %T Speed Index: Relating the Industrial Standard for User Perceived Web Performance to Web QoE
• Observations on Emerging Aspects in QoE Modeling and Their Impact on QoE Management Hoßfeld, Tobias; Varela, Martin; Heegaard, Poul E.; Skorin-Kapov, Lea in 2018 Tenth International Conference on Quality of Multimedia Experience (QoMEX) (2018).
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  @inproceedings{info3-inproceedings-2018-50, author = {Hoßfeld, Tobias and Varela, Martin and Heegaard, Poul E. and Skorin-Kapov, Lea}, booktitle = {2018 Tenth International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {sys:hidden:inproceedings}, title = {Observations on Emerging Aspects in QoE Modeling and Their Impact on QoE Management}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-50 %A Hoßfeld, Tobias %A Varela, Martin %A Heegaard, Poul E. %A Skorin-Kapov, Lea %B 2018 Tenth International Conference on Quality of Multimedia Experience (QoMEX) %D 2018 %T Observations on Emerging Aspects in QoE Modeling and Their Impact on QoE Management
• QoE Analysis of the Setup of Different Internet Services for FIFO Server Systems Hoßfeld, Tobias; Varela, Martin; Heegaard, Poul E.; Skorin-Kapov, Lea in Proceedings of the 19th International Conference on Measurement, Modelling and Evaluation of Computing Systems (MMB) (2018).
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  @inproceedings{info3-inproceedings-2018-8, address = {Erlangen, Germany}, author = {Hoßfeld, Tobias and Varela, Martin and Heegaard, Poul E. and Skorin-Kapov, Lea}, booktitle = {Proceedings of the 19th International Conference on Measurement, Modelling and Evaluation of Computing Systems (MMB)}, keywords = {sys:hidden:inproceedings}, month = 2, title = {QoE Analysis of the Setup of Different Internet Services for FIFO Server Systems}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-8 %A Hoßfeld, Tobias %A Varela, Martin %A Heegaard, Poul E. %A Skorin-Kapov, Lea %B Proceedings of the 19th International Conference on Measurement, Modelling and Evaluation of Computing Systems (MMB) %C Erlangen, Germany %D 2018 %T QoE Analysis of the Setup of Different Internet Services for FIFO Server Systems
• Taming the complexity of artifact reproducibility Flittner, Matthias; Bauer, Robert; Rizk, Amr; Geissler, Stefan; Zinner, Thomas; Zitterbart, Martina in Proceedings of the Reproducibility Workshop (2018).
  • [ Abstract ]
  • [ BibTeX ]
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  Reproducing research results, as it is required for peer review, can be a time-consuming and difficult task. In this work, we propose three approaches to improve the way of how research results can be substantiated and discuss their applicability. Our proposals are based on a brief study on evaluation methods (for SDN research) and insights from a comprehensive discussion on reproducibility.

  @inproceedings{info3-inproceedings-2018-45, abstract = {Reproducing research results, as it is required for peer review, can be a time-consuming and difficult task. In this work, we propose three approaches to improve the way of how research results can be substantiated and discuss their applicability. Our proposals are based on a brief study on evaluation methods (for SDN research) and insights from a comprehensive discussion on reproducibility.}, author = {Flittner, Matthias and Bauer, Robert and Rizk, Amr and Geissler, Stefan and Zinner, Thomas and Zitterbart, Martina}, booktitle = {Proceedings of the Reproducibility Workshop}, keywords = {ngn}, month = 8, title = {Taming the complexity of artifact reproducibility}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-45 %A Flittner, Matthias %A Bauer, Robert %A Rizk, Amr %A Geissler, Stefan %A Zinner, Thomas %A Zitterbart, Martina %B Proceedings of the Reproducibility Workshop %D 2018 %T Taming the complexity of artifact reproducibility %X Reproducing research results, as it is required for peer review, can be a time-consuming and difficult task. In this work, we propose three approaches to improve the way of how research results can be substantiated and discuss their applicability. Our proposals are based on a brief study on evaluation methods (for SDN research) and insights from a comprehensive discussion on reproducibility.
• A Cumulative Quality Model for HTTP Adaptive Streaming Tran, Huyen TT; Pham Ngoc, Nam; Hoßfeld, Tobias; Thang, Truong Cong in Tenth International Conference on Quality of Multimedia Experience (QoMEX) (2018).
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  @inproceedings{info3-inproceedings-2018-47, author = {Tran, Huyen TT and Pham Ngoc, Nam and Hoßfeld, Tobias and Thang, Truong Cong}, booktitle = {Tenth International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {sys:hidden:inproceedings}, month = 5, title = {A Cumulative Quality Model for HTTP Adaptive Streaming}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-47 %A Tran, Huyen TT %A Pham Ngoc, Nam %A Hoßfeld, Tobias %A Thang, Truong Cong %B Tenth International Conference on Quality of Multimedia Experience (QoMEX) %D 2018 %T A Cumulative Quality Model for HTTP Adaptive Streaming
• User Experience of Web Browsing-The Relationship of Usability and Quality of Experience Voigt-Antons, Jan-Niklas; Hoßfeld, Tobias; Egger-Lampl, Sebastian; Schatz, Raimund; Möller, Sebastian in Tenth International Conference on Quality of Multimedia Experience (QoMEX) (2018).
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  @inproceedings{info3-inproceedings-2018-48, author = {Voigt-Antons, Jan-Niklas and Hoßfeld, Tobias and Egger-Lampl, Sebastian and Schatz, Raimund and Möller, Sebastian}, booktitle = {Tenth International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {sys:hidden:inproceedings}, month = 5, title = {User Experience of Web Browsing-The Relationship of Usability and Quality of Experience}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-48 %A Voigt-Antons, Jan-Niklas %A Hoßfeld, Tobias %A Egger-Lampl, Sebastian %A Schatz, Raimund %A Möller, Sebastian %B Tenth International Conference on Quality of Multimedia Experience (QoMEX) %D 2018 %T User Experience of Web Browsing-The Relationship of Usability and Quality of Experience
• Bridging the Gap Between Programming and Implementation of Networking Devices Grigorjew, Alexej; Gray, Nicholas; Hoßfeld, Tobias; Shukla, Apoorv; Zinner, Thomas in Student Workshop of the 14th International Conference on emerging Networking EXperiments and Technologies (2018).
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  @inproceedings{info3-inproceedings-2018-49, author = {Grigorjew, Alexej and Gray, Nicholas and Hoßfeld, Tobias and Shukla, Apoorv and Zinner, Thomas}, booktitle = {Student Workshop of the 14th International Conference on emerging Networking EXperiments and Technologies}, keywords = {ngn}, month = 12, title = {Bridging the Gap Between Programming and Implementation of Networking Devices}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-49 %A Grigorjew, Alexej %A Gray, Nicholas %A Hoßfeld, Tobias %A Shukla, Apoorv %A Zinner, Thomas %B Student Workshop of the 14th International Conference on emerging Networking EXperiments and Technologies %D 2018 %T Bridging the Gap Between Programming and Implementation of Networking Devices
• Evaluation of the Detection Capabilities of the ONOS SDN Controller Metter, Christopher; Burger, Valentin; Hu, Zheng; Pei, Ke; Wamser, Florian in 7th IEEE International Conference on Communications and Electronics (IEEE ICCE 2018) (2018). 96–101.
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  The process of monitoring the network, especially for larger ones, is very complex and contains many pitfalls. For instance the balance between granularity of information and their performance impact on the network. With the help of SDN this challenge can become easier, as it offers new methods, mechanisms and opportunities. One of the current most important Open Source controllers is the ONOS SDN controller. According to its developers it is a production ready controller that offers high availability due to its logically centralized and physically distributed architecture. But, as our investigations show, it is unable to cope with hazardous network conditions such as sporadic or recurring packet loss. It either does not detect packet loss or only detects it after long time periods, failing all common network availability targets.

  @inproceedings{info3-inproceedings-2018-22, abstract = {The process of monitoring the network, especially for larger ones, is very complex and contains many pitfalls. For instance the balance between granularity of information and their performance impact on the network. With the help of SDN this challenge can become easier, as it offers new methods, mechanisms and opportunities. One of the current most important Open Source controllers is the ONOS SDN controller. According to its developers it is a production ready controller that offers high availability due to its logically centralized and physically distributed architecture. But, as our investigations show, it is unable to cope with hazardous network conditions such as sporadic or recurring packet loss. It either does not detect packet loss or only detects it after long time periods, failing all common network availability targets.}, address = {Hue, Vietnam}, author = {Metter, Christopher and Burger, Valentin and Hu, Zheng and Pei, Ke and Wamser, Florian}, booktitle = {7th IEEE International Conference on Communications and Electronics (IEEE ICCE 2018)}, keywords = {can}, month = 7, pages = {96 - 101}, title = {Evaluation of the Detection Capabilities of the ONOS SDN Controller}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-22 %A Metter, Christopher %A Burger, Valentin %A Hu, Zheng %A Pei, Ke %A Wamser, Florian %B 7th IEEE International Conference on Communications and Electronics (IEEE ICCE 2018) %C Hue, Vietnam %D 2018 %P 96 - 101 %T Evaluation of the Detection Capabilities of the ONOS SDN Controller %X The process of monitoring the network, especially for larger ones, is very complex and contains many pitfalls. For instance the balance between granularity of information and their performance impact on the network. With the help of SDN this challenge can become easier, as it offers new methods, mechanisms and opportunities. One of the current most important Open Source controllers is the ONOS SDN controller. According to its developers it is a production ready controller that offers high availability due to its logically centralized and physically distributed architecture. But, as our investigations show, it is unable to cope with hazardous network conditions such as sporadic or recurring packet loss. It either does not detect packet loss or only detects it after long time periods, failing all common network availability targets.
• Optimal Fairness and Quality in Video Streaming With Multiple Users Moldovan, Christian; Skorin-Kapov, Lea; Heegaard, Poul E.; Hoßfeld, Tobias in 30th International Teletraffic Congress (ITC 30) (2018). 6.
  • [ Abstract ]
  • [ BibTeX ]
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  With the majority of video distribution services relying on the HTTP adaptive streaming paradigm, a great deal of research is geared towards developing algorithms and solutions for improving user perceived quality while making efficient use of available resources. Our goal is to provide the means for benchmarking such solutions in the context of multiple users accessing Video on Demand content while sharing a bottleneck link. For that purpose, we propose a quadratic problem formulation to compute the theoretical optimum in terms of adaptation strategies and corresponding segment downloads across multiple users under given bandwidth constraints. By aiming to maximize both service quality and fairness, we quantify and compare the impact of different fairness objectives (bandwidth fairness, pattern fairness, and session fairness) on resulting quality and achieved QoE fairness. Based on conducted simulations and parameter studies, our results demonstrate the benefits of optimizing for session fairness as compared to other approaches.

  @inproceedings{info3-inproceedings-2018-37, abstract = {With the majority of video distribution services relying on the HTTP adaptive streaming paradigm, a great deal of research is geared towards developing algorithms and solutions for improving user perceived quality while making efficient use of available resources. Our goal is to provide the means for benchmarking such solutions in the context of multiple users accessing Video on Demand content while sharing a bottleneck link. For that purpose, we propose a quadratic problem formulation to compute the theoretical optimum in terms of adaptation strategies and corresponding segment downloads across multiple users under given bandwidth constraints. By aiming to maximize both service quality and fairness, we quantify and compare the impact of different fairness objectives (bandwidth fairness, pattern fairness, and session fairness) on resulting quality and achieved QoE fairness. Based on conducted simulations and parameter studies, our results demonstrate the benefits of optimizing for session fairness as compared to other approaches.}, address = {Vienna, Austria}, author = {Moldovan, Christian and Skorin-Kapov, Lea and Heegaard, Poul E. and Hoßfeld, Tobias}, booktitle = {30th International Teletraffic Congress (ITC 30)}, keywords = {can}, month = 9, pages = 6, title = {Optimal Fairness and Quality in Video Streaming With Multiple Users}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-37 %A Moldovan, Christian %A Skorin-Kapov, Lea %A Heegaard, Poul E. %A Hoßfeld, Tobias %B 30th International Teletraffic Congress (ITC 30) %C Vienna, Austria %D 2018 %P 6 %T Optimal Fairness and Quality in Video Streaming With Multiple Users %X With the majority of video distribution services relying on the HTTP adaptive streaming paradigm, a great deal of research is geared towards developing algorithms and solutions for improving user perceived quality while making efficient use of available resources. Our goal is to provide the means for benchmarking such solutions in the context of multiple users accessing Video on Demand content while sharing a bottleneck link. For that purpose, we propose a quadratic problem formulation to compute the theoretical optimum in terms of adaptation strategies and corresponding segment downloads across multiple users under given bandwidth constraints. By aiming to maximize both service quality and fairness, we quantify and compare the impact of different fairness objectives (bandwidth fairness, pattern fairness, and session fairness) on resulting quality and achieved QoE fairness. Based on conducted simulations and parameter studies, our results demonstrate the benefits of optimizing for session fairness as compared to other approaches.
• Exploring the Transmission Behaviour of Overwatch: The Source of Lag Metzger, Florian; Heger, Roman in 30th International Teletraffic Congress (ITC 30) (2018).
  • [ Abstract ]
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  This paper explores the full chain of lag contribution factors in a specific online multiplayer game, namely Overwatch: From creating input events over the network and back to displaying the results on the local screen. Together result in the dreaded end-to-end lag. which has a direct impact on the subjective quality one experiences when playing video games. In its investigation, this paper reveals surprising effects in the game's networking behavior that are omitted when colloquially talking about, e.g. a 60 Hz update rate, but must be considered nonetheless. These insights, gained from examining network traces of Overwatch matches that were played on a realistic, resource constrained PC, can then be used to refine end-to-end lag simulation models and reach a better understanding of all responsible components.

  @inproceedings{info3-inproceedings-2018-36, abstract = {This paper explores the full chain of lag contribution factors in a specific online multiplayer game, namely Overwatch: From creating input events over the network and back to displaying the results on the local screen. Together result in the dreaded end-to-end lag. which has a direct impact on the subjective quality one experiences when playing video games. In its investigation, this paper reveals surprising effects in the game's networking behavior that are omitted when colloquially talking about, e.g. a 60 Hz update rate, but must be considered nonetheless. These insights, gained from examining network traces of Overwatch matches that were played on a realistic, resource constrained PC, can then be used to refine end-to-end lag simulation models and reach a better understanding of all responsible components.}, author = {Metzger, Florian and Heger, Roman}, booktitle = {30th International Teletraffic Congress (ITC 30)}, keywords = {fullstack}, month = 9, title = {Exploring the Transmission Behaviour of Overwatch: The Source of Lag}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-36 %A Metzger, Florian %A Heger, Roman %B 30th International Teletraffic Congress (ITC 30) %D 2018 %T Exploring the Transmission Behaviour of Overwatch: The Source of Lag %X This paper explores the full chain of lag contribution factors in a specific online multiplayer game, namely Overwatch: From creating input events over the network and back to displaying the results on the local screen. Together result in the dreaded end-to-end lag. which has a direct impact on the subjective quality one experiences when playing video games. In its investigation, this paper reveals surprising effects in the game's networking behavior that are omitted when colloquially talking about, e.g. a 60 Hz update rate, but must be considered nonetheless. These insights, gained from examining network traces of Overwatch matches that were played on a realistic, resource constrained PC, can then be used to refine end-to-end lag simulation models and reach a better understanding of all responsible components.
• Practical QoE Evaluation of Adaptive Video Streaming Surminski, Sebastian; Moldovan, Christian; Hoßfeld, Tobias in Proceedings of the 19th International Conference on Measurement, Modelling and Evaluation of Computing Systems (MMB) (2018).
  • [ BibTeX ]
  • [ EndNote ]
  @inproceedings{info3-inproceedings-2018-7, address = {Erlangen, Germany}, author = {Surminski, Sebastian and Moldovan, Christian and Hoßfeld, Tobias}, booktitle = {Proceedings of the 19th International Conference on Measurement, Modelling and Evaluation of Computing Systems (MMB)}, keywords = {dfg-sdn}, month = 2, title = {Practical QoE Evaluation of Adaptive Video Streaming}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-7 %A Surminski, Sebastian %A Moldovan, Christian %A Hoßfeld, Tobias %B Proceedings of the 19th International Conference on Measurement, Modelling and Evaluation of Computing Systems (MMB) %C Erlangen, Germany %D 2018 %T Practical QoE Evaluation of Adaptive Video Streaming
• Towards an Active Probing Extension for the {ONOS} {SDN} Controller Metter, Christopher; Burger, Valentin; Hu, Zheng; Pei, Ke; Wamser, Florian in 2018 28th International Telecommunication Networks and Applications Conference (ITNAC) (ITNAC 2018) (2018). 8.
  • [ Abstract ]
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  Network monitoring is a complex task and is always a trade-off between granularity of information and the performance impact of the monitoring itself on the network. SDN controllers, such as the ONOS SDN controller make this challenge easier as they can supply centralized information over the whole network. In our previous work we mathematically analyzed the built-in detection mechanism of ONOS and revealed a lack of detection performance and the vulnerability of this process to jitter. These results were also verified by measurements. In this paper we present an Active Probing extension for the ONOS SDN controller that overcomes these shortcomings by emitting probing packets that are transmitted through the network. Statistics over a history of those packets allow for the detection of packet loss. The evaluation by the means of measurements proves the benefits in terms of detection performance and controller load of this application. Furthermore, our extension is able to detect jitter being present in the network and to automatically adapt the probing process to these conditions.

  @inproceedings{info3-inproceedings-2018-34, abstract = {Network monitoring is a complex task and is always a trade-off between granularity of information and the performance impact of the monitoring itself on the network. SDN controllers, such as the ONOS SDN controller make this challenge easier as they can supply centralized information over the whole network. In our previous work we mathematically analyzed the built-in detection mechanism of ONOS and revealed a lack of detection performance and the vulnerability of this process to jitter. These results were also verified by measurements. In this paper we present an Active Probing extension for the ONOS SDN controller that overcomes these shortcomings by emitting probing packets that are transmitted through the network. Statistics over a history of those packets allow for the detection of packet loss. The evaluation by the means of measurements proves the benefits in terms of detection performance and controller load of this application. Furthermore, our extension is able to detect jitter being present in the network and to automatically adapt the probing process to these conditions.}, address = {Sydney, Australia}, author = {Metter, Christopher and Burger, Valentin and Hu, Zheng and Pei, Ke and Wamser, Florian}, booktitle = {2018 28th International Telecommunication Networks and Applications Conference (ITNAC) (ITNAC 2018)}, keywords = {can}, month = 11, pages = 8, title = {Towards an Active Probing Extension for the {ONOS} {SDN} Controller}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-34 %A Metter, Christopher %A Burger, Valentin %A Hu, Zheng %A Pei, Ke %A Wamser, Florian %B 2018 28th International Telecommunication Networks and Applications Conference (ITNAC) (ITNAC 2018) %C Sydney, Australia %D 2018 %P 8 %T Towards an Active Probing Extension for the {ONOS} {SDN} Controller %X Network monitoring is a complex task and is always a trade-off between granularity of information and the performance impact of the monitoring itself on the network. SDN controllers, such as the ONOS SDN controller make this challenge easier as they can supply centralized information over the whole network. In our previous work we mathematically analyzed the built-in detection mechanism of ONOS and revealed a lack of detection performance and the vulnerability of this process to jitter. These results were also verified by measurements. In this paper we present an Active Probing extension for the ONOS SDN controller that overcomes these shortcomings by emitting probing packets that are transmitted through the network. Statistics over a history of those packets allow for the detection of packet loss. The evaluation by the means of measurements proves the benefits in terms of detection performance and controller load of this application. Furthermore, our extension is able to detect jitter being present in the network and to automatically adapt the probing process to these conditions.
• Estimating the Flow Rule Installation Time of SDN Switches when Facing Control Plane Delay Nguyen-Ngoc, Anh; Lange, Stanislav; Geissler, Stefan; Zinner, Thomas; Tran-Gia, Phuoc in 19th International GI/ITG Conference on “Measurement, Modelling and Evaluation of Computing Systems” (2018).
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  The software defined networking (SDN) paradigm has numerous benefits for network operators, including cost aspects, flexibility, and programmability. In the centralized SDN architecture, the controller can order the installation of flow rules in the switches it manages via FlowMod messages. Since the processing time of these messages has a direct impact on the reaction time of the network, it is a key performance indicator for switches and quantifying it in a reliable manner is required for ensuring state consistency between the control and the data plane. Furthermore, real world deployments not only consist of different data plane hardware, but may feature varying control plane delays. Hence, in this work, we investigate the impact of such a delay on the FlowMod processing time of OpenFlow switches. Firstly, we identify a significant heterogeneity between data plane hardware in terms of processing times as well as the underlying TCP-level behavior. Secondly, we show that despite this heterogeneity, combining switch specific information with delay measurements at the controller can be used to reliably infer FlowMod processing times. We confirm our results with measurements in a dedicated testbed that is comprised of three different hardware switches, three different SDN controllers, and several high precision measurement devices.

  @inproceedings{info3-inproceedings-2018-4, abstract = {The software defined networking (SDN) paradigm has numerous benefits for network operators, including cost aspects, flexibility, and programmability. In the centralized SDN architecture, the controller can order the installation of flow rules in the switches it manages via FlowMod messages. Since the processing time of these messages has a direct impact on the reaction time of the network, it is a key performance indicator for switches and quantifying it in a reliable manner is required for ensuring state consistency between the control and the data plane. Furthermore, real world deployments not only consist of different data plane hardware, but may feature varying control plane delays. Hence, in this work, we investigate the impact of such a delay on the FlowMod processing time of OpenFlow switches. Firstly, we identify a significant heterogeneity between data plane hardware in terms of processing times as well as the underlying TCP-level behavior. Secondly, we show that despite this heterogeneity, combining switch specific information with delay measurements at the controller can be used to reliably infer FlowMod processing times. We confirm our results with measurements in a dedicated testbed that is comprised of three different hardware switches, three different SDN controllers, and several high precision measurement devices.}, address = {Erlangen}, author = {Nguyen-Ngoc, Anh and Lange, Stanislav and Geissler, Stefan and Zinner, Thomas and Tran-Gia, Phuoc}, booktitle = {19th International GI/ITG Conference on “Measurement, Modelling and Evaluation of Computing Systems”}, keywords = {ngn}, month = 2, title = {Estimating the Flow Rule Installation Time of SDN Switches when Facing Control Plane Delay}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-4 %A Nguyen-Ngoc, Anh %A Lange, Stanislav %A Geissler, Stefan %A Zinner, Thomas %A Tran-Gia, Phuoc %B 19th International GI/ITG Conference on “Measurement, Modelling and Evaluation of Computing Systems” %C Erlangen %D 2018 %T Estimating the Flow Rule Installation Time of SDN Switches when Facing Control Plane Delay %X The software defined networking (SDN) paradigm has numerous benefits for network operators, including cost aspects, flexibility, and programmability. In the centralized SDN architecture, the controller can order the installation of flow rules in the switches it manages via FlowMod messages. Since the processing time of these messages has a direct impact on the reaction time of the network, it is a key performance indicator for switches and quantifying it in a reliable manner is required for ensuring state consistency between the control and the data plane. Furthermore, real world deployments not only consist of different data plane hardware, but may feature varying control plane delays. Hence, in this work, we investigate the impact of such a delay on the FlowMod processing time of OpenFlow switches. Firstly, we identify a significant heterogeneity between data plane hardware in terms of processing times as well as the underlying TCP-level behavior. Secondly, we show that despite this heterogeneity, combining switch specific information with delay measurements at the controller can be used to reliably infer FlowMod processing times. We confirm our results with measurements in a dedicated testbed that is comprised of three different hardware switches, three different SDN controllers, and several high precision measurement devices.
• How do crowdworker communities and microtask markets influenceeach other? A data-driven study on Amazon Mechanical Turk Yang, Jie; van der Valk, Carlo; Hoßfeld, Tobias; Redi, Judith; Bozzon, Alessandro in Sixth AAAI Conference on Human Computation and Crowdsourcing (2018).
  • [ BibTeX ]
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  @inproceedings{info3-techreport-2018-1, author = {Yang, Jie and van der Valk, Carlo and Hoßfeld, Tobias and Redi, Judith and Bozzon, Alessandro}, booktitle = {Sixth AAAI Conference on Human Computation and Crowdsourcing}, keywords = {sys:hidden:inproceedings}, title = {How do crowdworker communities and microtask markets influenceeach other? A data-driven study on Amazon Mechanical Turk}, year = 2018 }

  %0 Conference Paper %1 info3-techreport-2018-1 %A Yang, Jie %A van der Valk, Carlo %A Hoßfeld, Tobias %A Redi, Judith %A Bozzon, Alessandro %B Sixth AAAI Conference on Human Computation and Crowdsourcing %D 2018 %T How do crowdworker communities and microtask markets influenceeach other? A data-driven study on Amazon Mechanical Turk
• Performance Benchmarking of Network Function Chain Placement Algorithms Grigorjew, Alexej; Lange, Stanislav; Zinner, Thomas; Tran-Gia, Phuoc in 19th International GI/ITG Conference on Measurement, Modelling and Evaluation of Computing Systems (MMB) (2018).
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  @inproceedings{info3-inproceedings-2018-1, author = {Grigorjew, Alexej and Lange, Stanislav and Zinner, Thomas and Tran-Gia, Phuoc}, booktitle = {19th International GI/ITG Conference on Measurement, Modelling and Evaluation of Computing Systems (MMB)}, keywords = {ngn}, month = 2, title = {Performance Benchmarking of Network Function Chain Placement Algorithms}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-1 %A Grigorjew, Alexej %A Lange, Stanislav %A Zinner, Thomas %A Tran-Gia, Phuoc %B 19th International GI/ITG Conference on Measurement, Modelling and Evaluation of Computing Systems (MMB) %D 2018 %T Performance Benchmarking of Network Function Chain Placement Algorithms
• Performance Evaluation of Mobile Crowdsensing for Event Detection Hirth, Matthias; Lange, Stanislav; Seufert, Michael; Tran-Gia, Phuoc in Proceedings of the 5th International Workshop on Crowd Assisted Sensing, Pervasive Systems and Communications (2018).
  • [ Abstract ]
  • [ BibTeX ]
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  Crowdsensing offers a cost effective way to collect large amounts of sensor data. However, in contrast to fixed sensor deployments, the spatial distribution of the sensors can hardly be influence, as the sensors are carried by participants of the crowdsensing system. This in turn raises the question about the performance of such systems with respect to the detection probability and detection time of spatial events. In order to address this question, we analyze the performance of such a crowdsensing system by means of simulation. We use the traffic infrastructure of a small size city in Germany and simulate the inhabitants’ movement patterns with the well established SUMO mobility generator. Our results show that even if only a small share of inhabitants participates in crowdsensing, events, which have locations that are correlated with the population density, can be easily and quickly detected using such a system. On the contrary, events whose locations are uniformly randomly distributed are much harder to detect using a crowdsensing approach.

  @inproceedings{info3-inproceedings-2017-21, abstract = {Crowdsensing offers a cost effective way to collect large amounts of sensor data. However, in contrast to fixed sensor deployments, the spatial distribution of the sensors can hardly be influence, as the sensors are carried by participants of the crowdsensing system. This in turn raises the question about the performance of such systems with respect to the detection probability and detection time of spatial events. In order to address this question, we analyze the performance of such a crowdsensing system by means of simulation. We use the traffic infrastructure of a small size city in Germany and simulate the inhabitants’ movement patterns with the well established SUMO mobility generator. Our results show that even if only a small share of inhabitants participates in crowdsensing, events, which have locations that are correlated with the population density, can be easily and quickly detected using such a system. On the contrary, events whose locations are uniformly randomly distributed are much harder to detect using a crowdsensing approach.}, address = {Athens, Greece}, author = {Hirth, Matthias and Lange, Stanislav and Seufert, Michael and Tran-Gia, Phuoc}, booktitle = {Proceedings of the 5th International Workshop on Crowd Assisted Sensing, Pervasive Systems and Communications}, keywords = {sys:hidden:inproceedings}, month = 3, title = {Performance Evaluation of Mobile Crowdsensing for Event Detection}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2017-21 %A Hirth, Matthias %A Lange, Stanislav %A Seufert, Michael %A Tran-Gia, Phuoc %B Proceedings of the 5th International Workshop on Crowd Assisted Sensing, Pervasive Systems and Communications %C Athens, Greece %D 2018 %T Performance Evaluation of Mobile Crowdsensing for Event Detection %X Crowdsensing offers a cost effective way to collect large amounts of sensor data. However, in contrast to fixed sensor deployments, the spatial distribution of the sensors can hardly be influence, as the sensors are carried by participants of the crowdsensing system. This in turn raises the question about the performance of such systems with respect to the detection probability and detection time of spatial events. In order to address this question, we analyze the performance of such a crowdsensing system by means of simulation. We use the traffic infrastructure of a small size city in Germany and simulate the inhabitants’ movement patterns with the well established SUMO mobility generator. Our results show that even if only a small share of inhabitants participates in crowdsensing, events, which have locations that are correlated with the population density, can be easily and quickly detected using such a system. On the contrary, events whose locations are uniformly randomly distributed are much harder to detect using a crowdsensing approach.
• Traffic Modeling for Aggregated Periodic IoT Data Hoßfeld, Tobias; Metzger, Florian; Heegaard, Poul E. in Proceedings of the 21st Conference on Innovation in Clouds, Internet and Networks (ICIN) (2018).
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  @inproceedings{info3-inproceedings-2018-6, address = {Paris, France}, author = {Hoßfeld, Tobias and Metzger, Florian and Heegaard, Poul E.}, booktitle = {Proceedings of the 21st Conference on Innovation in Clouds, Internet and Networks (ICIN)}, keywords = {fullstack}, month = 2, title = {Traffic Modeling for Aggregated Periodic IoT Data}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-6 %A Hoßfeld, Tobias %A Metzger, Florian %A Heegaard, Poul E. %B Proceedings of the 21st Conference on Innovation in Clouds, Internet and Networks (ICIN) %C Paris, France %D 2018 %T Traffic Modeling for Aggregated Periodic IoT Data
• Quality of Service Assessment of Live Video Streaming with a Remote-Controlled Drone Loh, Frank; Wamser, Florian; Hoßfeld, Tobias; Tran-Gia, Phuoc in IEEE Conference on Network Softwarization (2018).
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  Today's networks require a deep understanding of applications to optimize networks, efficiently design networks, and meet traffic demands, application heterogeneity, and application requirements. Current application areas include live video streaming and real-time applications, such as those that are named in 5G use cases with automation, disaster recovery, gaming, and Industry 4.0. In this work, we examine an application scenario with live video streaming and parallel real-time requirements in the uplink for disaster recovery. We study the quality of service (QoS) features of a remote-controlled drone. The drone is controlled via a tablet or smartphone while the video from the camera is transmitted from the drone to the user. There are high demands in both the uplink and downlink direction. The contribution of the work is the measurement of the QoS and application parameters for this scenario and the definition of influencing parameters for the application-layer.

  @inproceedings{info3-inproceedings-2018-31, abstract = {Today's networks require a deep understanding of applications to optimize networks, efficiently design networks, and meet traffic demands, application heterogeneity, and application requirements. Current application areas include live video streaming and real-time applications, such as those that are named in 5G use cases with automation, disaster recovery, gaming, and Industry 4.0. In this work, we examine an application scenario with live video streaming and parallel real-time requirements in the uplink for disaster recovery. We study the quality of service (QoS) features of a remote-controlled drone. The drone is controlled via a tablet or smartphone while the video from the camera is transmitted from the drone to the user. There are high demands in both the uplink and downlink direction. The contribution of the work is the measurement of the QoS and application parameters for this scenario and the definition of influencing parameters for the application-layer.}, address = {Montreal, Canada}, author = {Loh, Frank and Wamser, Florian and Hoßfeld, Tobias and Tran-Gia, Phuoc}, booktitle = {IEEE Conference on Network Softwarization}, keywords = {can}, month = 7, title = {Quality of Service Assessment of Live Video Streaming with a Remote-Controlled Drone}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-31 %A Loh, Frank %A Wamser, Florian %A Hoßfeld, Tobias %A Tran-Gia, Phuoc %B IEEE Conference on Network Softwarization %C Montreal, Canada %D 2018 %T Quality of Service Assessment of Live Video Streaming with a Remote-Controlled Drone %X Today's networks require a deep understanding of applications to optimize networks, efficiently design networks, and meet traffic demands, application heterogeneity, and application requirements. Current application areas include live video streaming and real-time applications, such as those that are named in 5G use cases with automation, disaster recovery, gaming, and Industry 4.0. In this work, we examine an application scenario with live video streaming and parallel real-time requirements in the uplink for disaster recovery. We study the quality of service (QoS) features of a remote-controlled drone. The drone is controlled via a tablet or smartphone while the video from the camera is transmitted from the drone to the user. There are high demands in both the uplink and downlink direction. The contribution of the work is the measurement of the QoS and application parameters for this scenario and the definition of influencing parameters for the application-layer.
• Application of Visual Analysis to Detect and Analyze Patterns in VoIP Attack Traffic Volodina, Ekaterina; Aziz, Adnan; Rathgeb, Erwin; Hoßfeld, Tobias in 17th IEEE International Conference On Trust, Security And Privacy In Computing And Communications/12th IEEE International Conference On Big Data Science And Engineering (TrustCom/BigDataSE) (2018).
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  @inproceedings{info3-inproceedings-2018-35, author = {Volodina, Ekaterina and Aziz, Adnan and Rathgeb, Erwin and Hoßfeld, Tobias}, booktitle = {17th IEEE International Conference On Trust, Security And Privacy In Computing And Communications/12th IEEE International Conference On Big Data Science And Engineering (TrustCom/BigDataSE)}, keywords = {sys:hidden:inproceedings}, month = 8, title = {Application of Visual Analysis to Detect and Analyze Patterns in VoIP Attack Traffic}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-35 %A Volodina, Ekaterina %A Aziz, Adnan %A Rathgeb, Erwin %A Hoßfeld, Tobias %B 17th IEEE International Conference On Trust, Security And Privacy In Computing And Communications/12th IEEE International Conference On Big Data Science And Engineering (TrustCom/BigDataSE) %D 2018 %T Application of Visual Analysis to Detect and Analyze Patterns in VoIP Attack Traffic
• Evaluation of a Distributed Control Plane for Managing Heterogeneous SDN-enabled and Legacy Networks Gray, Nicholas; Lange, Stanislav; Zinner, Thomas; Pfaff, Benedikt; Hock, David in 7th International Conference on Communications and Electronics (ICCE) (2018).
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  With the increasing number of devices, protocols and applications, today’s networks are becoming more and more complex. Hence, Software-defined Networking (SDN) tries to ad- dress this issue by separating the data from the control plane and by providing centralized interfaces for network configuration. As legacy devices cannot be replaced instantly due to high costs, both network segments have to be operated in coexistence with defined joints at their edges. To ensure a smooth operation, both controlling instances of these segments are required to exchange information. In this work, we design and implement a data model for storing the information needed to keep the controller and a Network Management System (NMS) synchronized, which are responsible for configuring the SDN-enabled network and the legacy devices respectively. For this, we implement and evaluate a total of three different synchronization strategies by the example of an SDN-based Bring Your Own Device (BYOD) use case. Index Terms—SDN, NMS, Management, Integration, Hetero- geneous Networks, Distributed Control Plane.

  @inproceedings{info3-inproceedings-2018-33, abstract = {With the increasing number of devices, protocols and applications, today’s networks are becoming more and more complex. Hence, Software-defined Networking (SDN) tries to ad- dress this issue by separating the data from the control plane and by providing centralized interfaces for network configuration. As legacy devices cannot be replaced instantly due to high costs, both network segments have to be operated in coexistence with defined joints at their edges. To ensure a smooth operation, both controlling instances of these segments are required to exchange information. In this work, we design and implement a data model for storing the information needed to keep the controller and a Network Management System (NMS) synchronized, which are responsible for configuring the SDN-enabled network and the legacy devices respectively. For this, we implement and evaluate a total of three different synchronization strategies by the example of an SDN-based Bring Your Own Device (BYOD) use case. Index Terms—SDN, NMS, Management, Integration, Hetero- geneous Networks, Distributed Control Plane.}, address = {Hue, Vietnam}, author = {Gray, Nicholas and Lange, Stanislav and Zinner, Thomas and Pfaff, Benedikt and Hock, David}, booktitle = {7th International Conference on Communications and Electronics (ICCE)}, keywords = {ngn}, month = 7, title = {Evaluation of a Distributed Control Plane for Managing Heterogeneous SDN-enabled and Legacy Networks}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-33 %A Gray, Nicholas %A Lange, Stanislav %A Zinner, Thomas %A Pfaff, Benedikt %A Hock, David %B 7th International Conference on Communications and Electronics (ICCE) %C Hue, Vietnam %D 2018 %T Evaluation of a Distributed Control Plane for Managing Heterogeneous SDN-enabled and Legacy Networks %X With the increasing number of devices, protocols and applications, today’s networks are becoming more and more complex. Hence, Software-defined Networking (SDN) tries to ad- dress this issue by separating the data from the control plane and by providing centralized interfaces for network configuration. As legacy devices cannot be replaced instantly due to high costs, both network segments have to be operated in coexistence with defined joints at their edges. To ensure a smooth operation, both controlling instances of these segments are required to exchange information. In this work, we design and implement a data model for storing the information needed to keep the controller and a Network Management System (NMS) synchronized, which are responsible for configuring the SDN-enabled network and the legacy devices respectively. For this, we implement and evaluate a total of three different synchronization strategies by the example of an SDN-based Bring Your Own Device (BYOD) use case. Index Terms—SDN, NMS, Management, Integration, Hetero- geneous Networks, Distributed Control Plane.
• Integrating Network Management Information into the SDN Control Plane Lange, Stanislav; Reinhart, Lorenz; Zinner, Thomas; Hock, David; Gray, Nicholas; Tran-Gia, Phuoc in IEEE/IFIP Network Operations and Management Symposium (NOMS) (2018).
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  With software defined networking (SDN), operators benefit from a higher flexibility, cost efficiency, as well as programmability of their networks. Since modern networks are comprised of a multitude of heterogeneous devices and also include non-SDN legacy devices, network management systems (NMSs) are often used in order to monitor and configure the network. Although both, the SDN controller and the NMS, have a centralized view of the network, they operate at different time scales and deal with information at different levels of granularity. In this work, we investigate the impact on the network performance when an NMS regularly provides information to an SDN controller. To this end, we design, implement, and compare three interaction mechanisms based on the ONOS controller. These represent different trade-offs regarding the complexity of the resulting system and its performance. In addition to the default ONOS controller, we develop two extended versions. One performs hash-based load balancing on equal cost paths while the other utilizes external NMS information via ONOS's intent and annotation framework to optimize control plane decisions. In addition to evaluations that show a significant performance improvement when using the optimized controllers, we present a parameter study that highlights the performance impact of network characteristics like the flow interarrival time, the flow duration, and the number of active flows.

  @inproceedings{info3-inproceedings-2018-10, abstract = {With software defined networking (SDN), operators benefit from a higher flexibility, cost efficiency, as well as programmability of their networks. Since modern networks are comprised of a multitude of heterogeneous devices and also include non-SDN legacy devices, network management systems (NMSs) are often used in order to monitor and configure the network. Although both, the SDN controller and the NMS, have a centralized view of the network, they operate at different time scales and deal with information at different levels of granularity. In this work, we investigate the impact on the network performance when an NMS regularly provides information to an SDN controller. To this end, we design, implement, and compare three interaction mechanisms based on the ONOS controller. These represent different trade-offs regarding the complexity of the resulting system and its performance. In addition to the default ONOS controller, we develop two extended versions. One performs hash-based load balancing on equal cost paths while the other utilizes external NMS information via ONOS's intent and annotation framework to optimize control plane decisions. In addition to evaluations that show a significant performance improvement when using the optimized controllers, we present a parameter study that highlights the performance impact of network characteristics like the flow interarrival time, the flow duration, and the number of active flows.}, author = {Lange, Stanislav and Reinhart, Lorenz and Zinner, Thomas and Hock, David and Gray, Nicholas and Tran-Gia, Phuoc}, booktitle = {IEEE/IFIP Network Operations and Management Symposium (NOMS)}, keywords = {ngn}, month = 4, title = {Integrating Network Management Information into the SDN Control Plane}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-10 %A Lange, Stanislav %A Reinhart, Lorenz %A Zinner, Thomas %A Hock, David %A Gray, Nicholas %A Tran-Gia, Phuoc %B IEEE/IFIP Network Operations and Management Symposium (NOMS) %D 2018 %T Integrating Network Management Information into the SDN Control Plane %X With software defined networking (SDN), operators benefit from a higher flexibility, cost efficiency, as well as programmability of their networks. Since modern networks are comprised of a multitude of heterogeneous devices and also include non-SDN legacy devices, network management systems (NMSs) are often used in order to monitor and configure the network. Although both, the SDN controller and the NMS, have a centralized view of the network, they operate at different time scales and deal with information at different levels of granularity. In this work, we investigate the impact on the network performance when an NMS regularly provides information to an SDN controller. To this end, we design, implement, and compare three interaction mechanisms based on the ONOS controller. These represent different trade-offs regarding the complexity of the resulting system and its performance. In addition to the default ONOS controller, we develop two extended versions. One performs hash-based load balancing on equal cost paths while the other utilizes external NMS information via ONOS's intent and annotation framework to optimize control plane decisions. In addition to evaluations that show a significant performance improvement when using the optimized controllers, we present a parameter study that highlights the performance impact of network characteristics like the flow interarrival time, the flow duration, and the number of active flows.
• Orchestration and Monitoring in Fog Computing for Personal Edge Cloud Service Support Wamser, Florian; Lombardo, Chiara; Vassilakis, Constantinos; Dinh-Xuan, Lam; Lago, Paolo; Bruschi, Roberto; Tran-Gia, Phuoc in 2018 IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN) (2018).
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  @inproceedings{info3-inproceedings-2018-30, author = {Wamser, Florian and Lombardo, Chiara and Vassilakis, Constantinos and Dinh-Xuan, Lam and Lago, Paolo and Bruschi, Roberto and Tran-Gia, Phuoc}, booktitle = {2018 IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN)}, keywords = {can}, month = 6, title = {Orchestration and Monitoring in Fog Computing for Personal Edge Cloud Service Support}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-30 %A Wamser, Florian %A Lombardo, Chiara %A Vassilakis, Constantinos %A Dinh-Xuan, Lam %A Lago, Paolo %A Bruschi, Roberto %A Tran-Gia, Phuoc %B 2018 IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN) %D 2018 %T Orchestration and Monitoring in Fog Computing for Personal Edge Cloud Service Support
• Performance Evaluation of Service Functions Chain Placement Algorithms in Edge Cloud Dinh-Xuan, Lam; Seufert, Michael; Wamser, Florian; Vassilakis, Constantinos; Zafeiropoulos, Anastasios; Tran-Gia, Phuoc in 30th International Teletraffic Congress (ITC30) (2018).
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  The emergence of Network Function Virtualization (NFV) paradigm has become a potential solution dealing with the rapid growth of the global Internet traffic in the last decades. There, network appliances are transformed into Virtual Network Functions (VNF) running on a standard server. This promises to significantly reduce overall cost and energy consumption. Additionally, hardware-based network function chain is replaced by a chain of the VNFs, called Service Function Chain (SFC). The expected benefit of SFC is the reduction in the complexity when deploying heterogeneous network services. However, the considerable drawback of SFC is the distribution of the VNFs over different hosts. An inefficient placement of VNFs can induce a high latency within the chain and wasted server resources. In this work, we propose four placement algorithms that aim to efficiently place the SFC in servers with regard to minimizing service response time and resource utilization. Herein, heuristic approaches are evaluated against optimal solutions for the placement problems, which are formulated by using Integer Linear Programming. We evaluate and compare these placement strategies in a simulator. Our result shows that the optimized solutions produce lowest service response time and least server utilization in all types of simulated SFCs. On the other hand, the heuristic algorithms are also able to come close to the optimum by simple placing rules.

  @inproceedings{info3-inproceedings-2018-14, abstract = {The emergence of Network Function Virtualization (NFV) paradigm has become a potential solution dealing with the rapid growth of the global Internet traffic in the last decades. There, network appliances are transformed into Virtual Network Functions (VNF) running on a standard server. This promises to significantly reduce overall cost and energy consumption. Additionally, hardware-based network function chain is replaced by a chain of the VNFs, called Service Function Chain (SFC). The expected benefit of SFC is the reduction in the complexity when deploying heterogeneous network services. However, the considerable drawback of SFC is the distribution of the VNFs over different hosts. An inefficient placement of VNFs can induce a high latency within the chain and wasted server resources. In this work, we propose four placement algorithms that aim to efficiently place the SFC in servers with regard to minimizing service response time and resource utilization. Herein, heuristic approaches are evaluated against optimal solutions for the placement problems, which are formulated by using Integer Linear Programming. We evaluate and compare these placement strategies in a simulator. Our result shows that the optimized solutions produce lowest service response time and least server utilization in all types of simulated SFCs. On the other hand, the heuristic algorithms are also able to come close to the optimum by simple placing rules.}, address = {Vienna, Austria}, author = {Dinh-Xuan, Lam and Seufert, Michael and Wamser, Florian and Vassilakis, Constantinos and Zafeiropoulos, Anastasios and Tran-Gia, Phuoc}, booktitle = {30th International Teletraffic Congress (ITC30)}, keywords = {can}, month = 9, title = {Performance Evaluation of Service Functions Chain Placement Algorithms in Edge Cloud}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-14 %A Dinh-Xuan, Lam %A Seufert, Michael %A Wamser, Florian %A Vassilakis, Constantinos %A Zafeiropoulos, Anastasios %A Tran-Gia, Phuoc %B 30th International Teletraffic Congress (ITC30) %C Vienna, Austria %D 2018 %T Performance Evaluation of Service Functions Chain Placement Algorithms in Edge Cloud %X The emergence of Network Function Virtualization (NFV) paradigm has become a potential solution dealing with the rapid growth of the global Internet traffic in the last decades. There, network appliances are transformed into Virtual Network Functions (VNF) running on a standard server. This promises to significantly reduce overall cost and energy consumption. Additionally, hardware-based network function chain is replaced by a chain of the VNFs, called Service Function Chain (SFC). The expected benefit of SFC is the reduction in the complexity when deploying heterogeneous network services. However, the considerable drawback of SFC is the distribution of the VNFs over different hosts. An inefficient placement of VNFs can induce a high latency within the chain and wasted server resources. In this work, we propose four placement algorithms that aim to efficiently place the SFC in servers with regard to minimizing service response time and resource utilization. Herein, heuristic approaches are evaluated against optimal solutions for the placement problems, which are formulated by using Integer Linear Programming. We evaluate and compare these placement strategies in a simulator. Our result shows that the optimized solutions produce lowest service response time and least server utilization in all types of simulated SFCs. On the other hand, the heuristic algorithms are also able to come close to the optimum by simple placing rules.
• Enhancing Machine Learning based QoE Prediction by Ensemble Models Casas, Pedro; Seufert, Michael; Wehner, Nikolas; Schwind, Anika; Wamser, Florian in 3rd Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) (2018).
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  The number of smartphones connected to wireless networks and the volume of wireless network traffic generated by such devices have dramatically increased in the last few years, making it more challenging to tackle wireless network monitoring applications. The high-dimensionality of network data provided by current smartphone devices opens the door to the massive application of machine learning approaches to improve different wireless networking applications. In this paper we study the specific problem of Quality of Experience (QoE) prediction for popular smartphone apps, using machine learning models and in-smartphone measurements. We evaluate and compare different models for the analysis of smartphone generated data, including single models as well as machine learning ensembles such as bagging, boosting and stacking. Results suggest that, while decision-tree based models are the most accurate single models to predict QoE, ensemble learning models, and in particular stacking ones, are capable to significantly increase accuracy prediction and overall classification performance.

  @inproceedings{info3-inproceedings-2018-29, abstract = {The number of smartphones connected to wireless networks and the volume of wireless network traffic generated by such devices have dramatically increased in the last few years, making it more challenging to tackle wireless network monitoring applications. The high-dimensionality of network data provided by current smartphone devices opens the door to the massive application of machine learning approaches to improve different wireless networking applications. In this paper we study the specific problem of Quality of Experience (QoE) prediction for popular smartphone apps, using machine learning models and in-smartphone measurements. We evaluate and compare different models for the analysis of smartphone generated data, including single models as well as machine learning ensembles such as bagging, boosting and stacking. Results suggest that, while decision-tree based models are the most accurate single models to predict QoE, ensemble learning models, and in particular stacking ones, are capable to significantly increase accuracy prediction and overall classification performance.}, address = {Vienna, Austria}, author = {Casas, Pedro and Seufert, Michael and Wehner, Nikolas and Schwind, Anika and Wamser, Florian}, booktitle = {3rd Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE)}, keywords = {can}, month = 7, title = {Enhancing Machine Learning based QoE Prediction by Ensemble Models}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-29 %A Casas, Pedro %A Seufert, Michael %A Wehner, Nikolas %A Schwind, Anika %A Wamser, Florian %B 3rd Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) %C Vienna, Austria %D 2018 %T Enhancing Machine Learning based QoE Prediction by Ensemble Models %X The number of smartphones connected to wireless networks and the volume of wireless network traffic generated by such devices have dramatically increased in the last few years, making it more challenging to tackle wireless network monitoring applications. The high-dimensionality of network data provided by current smartphone devices opens the door to the massive application of machine learning approaches to improve different wireless networking applications. In this paper we study the specific problem of Quality of Experience (QoE) prediction for popular smartphone apps, using machine learning models and in-smartphone measurements. We evaluate and compare different models for the analysis of smartphone generated data, including single models as well as machine learning ensembles such as bagging, boosting and stacking. Results suggest that, while decision-tree based models are the most accurate single models to predict QoE, ensemble learning models, and in particular stacking ones, are capable to significantly increase accuracy prediction and overall classification performance.
• Streaming Characteristics of Spotify Sessions Schwind, Anika; Wamser, Florian; Gensler, Thomas; Seufert, Michael; Casas, Pedro; Tran-Gia, Phuoc in The 2nd International Workshop on Quality of Experience Management (2018).
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  Internet Service Providers need a thorough understanding of a service to maximize the Quality of Experience (QoE) of their customers by network management. Instead of quantifying the user satisfaction with long and cost-intensive subjective user studies, the QoE can often be estimated with the help of dedicated measurements of application and network parameters. We designed a QoE measurement tool for the popular audio streaming service Spotify that runs inside a Docker software container. The container is able to run headlessly as active measurement probe and emulates a user who is streaming audio files via Spotify. While streaming, network and application parameters are collected that have a high correlation to the user's QoE. The results of the measurements are used to characterize audio streaming in Spotify on application and network layer, and to evaluate important QoE factors.

  @inproceedings{info3-inproceedings-2018-13, abstract = {Internet Service Providers need a thorough understanding of a service to maximize the Quality of Experience (QoE) of their customers by network management. Instead of quantifying the user satisfaction with long and cost-intensive subjective user studies, the QoE can often be estimated with the help of dedicated measurements of application and network parameters. We designed a QoE measurement tool for the popular audio streaming service Spotify that runs inside a Docker software container. The container is able to run headlessly as active measurement probe and emulates a user who is streaming audio files via Spotify. While streaming, network and application parameters are collected that have a high correlation to the user's QoE. The results of the measurements are used to characterize audio streaming in Spotify on application and network layer, and to evaluate important QoE factors.}, address = {Sardinia, Italy}, author = {Schwind, Anika and Wamser, Florian and Gensler, Thomas and Seufert, Michael and Casas, Pedro and Tran-Gia, Phuoc}, booktitle = {The 2nd International Workshop on Quality of Experience Management}, keywords = {can}, month = 5, title = {Streaming Characteristics of Spotify Sessions}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-13 %A Schwind, Anika %A Wamser, Florian %A Gensler, Thomas %A Seufert, Michael %A Casas, Pedro %A Tran-Gia, Phuoc %B The 2nd International Workshop on Quality of Experience Management %C Sardinia, Italy %D 2018 %T Streaming Characteristics of Spotify Sessions %X Internet Service Providers need a thorough understanding of a service to maximize the Quality of Experience (QoE) of their customers by network management. Instead of quantifying the user satisfaction with long and cost-intensive subjective user studies, the QoE can often be estimated with the help of dedicated measurements of application and network parameters. We designed a QoE measurement tool for the popular audio streaming service Spotify that runs inside a Docker software container. The container is able to run headlessly as active measurement probe and emulates a user who is streaming audio files via Spotify. While streaming, network and application parameters are collected that have a high correlation to the user's QoE. The results of the measurements are used to characterize audio streaming in Spotify on application and network layer, and to evaluate important QoE factors.
• A Wrapper for Automatic Measurements with YouTube’s Native Android App Seufert, Michael; Zeidler, Bernd; Wamser, Florian; Karagkioules, Theodoros; Tsilimantos, Dimitrios; Loh, Frank; Tran-Gia, Phuoc; Valentin, Stefan in Network Traffic Measurement and Analysis Conference (TMA) (2018).
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  YouTube is one of the most popular and demanding services in the Internet today. Thereby, a large portion of this traffic is generated by YouTube's mobile app. While past studies have shown how to monitor browser-based streaming on desktop PCs (e.g., YoMo) or mobile devices (e.g., YoMoApp), streaming in the native app has not been monitored yet. This paper presents an automated framework for monitoring the streaming in YouTube's native app for Android. The concept is based on a wrapper application and the Android Debug Bridge (adb), and can be also extended to automatic measurements with other apps. For YouTube, it allows to collect application-layer streaming data, such as current playtime, buffered playtime, video encoding, and quality switches. These data can be complemented with network measurements on the mobile access link to obtain a holistic view on mobile YouTube streaming on Android devices. In addition to describing the software design and testbed setup, this paper discusses an experimental measurement. This study analyzes the streaming in the native YouTube app and compares it to the streaming from the mobile YouTube website via YoMoApp.

  @inproceedings{info3-article-2018-4, abstract = {YouTube is one of the most popular and demanding services in the Internet today. Thereby, a large portion of this traffic is generated by YouTube's mobile app. While past studies have shown how to monitor browser-based streaming on desktop PCs (e.g., YoMo) or mobile devices (e.g., YoMoApp), streaming in the native app has not been monitored yet. This paper presents an automated framework for monitoring the streaming in YouTube's native app for Android. The concept is based on a wrapper application and the Android Debug Bridge (adb), and can be also extended to automatic measurements with other apps. For YouTube, it allows to collect application-layer streaming data, such as current playtime, buffered playtime, video encoding, and quality switches. These data can be complemented with network measurements on the mobile access link to obtain a holistic view on mobile YouTube streaming on Android devices. In addition to describing the software design and testbed setup, this paper discusses an experimental measurement. This study analyzes the streaming in the native YouTube app and compares it to the streaming from the mobile YouTube website via YoMoApp.}, address = {Vienna, Austria}, author = {Seufert, Michael and Zeidler, Bernd and Wamser, Florian and Karagkioules, Theodoros and Tsilimantos, Dimitrios and Loh, Frank and Tran-Gia, Phuoc and Valentin, Stefan}, booktitle = {Network Traffic Measurement and Analysis Conference (TMA)}, keywords = {can}, month = 4, title = {A Wrapper for Automatic Measurements with YouTube's Native Android App}, year = 2018 }

  %0 Conference Paper %1 info3-article-2018-4 %A Seufert, Michael %A Zeidler, Bernd %A Wamser, Florian %A Karagkioules, Theodoros %A Tsilimantos, Dimitrios %A Loh, Frank %A Tran-Gia, Phuoc %A Valentin, Stefan %B Network Traffic Measurement and Analysis Conference (TMA) %C Vienna, Austria %D 2018 %T A Wrapper for Automatic Measurements with YouTube's Native Android App %X YouTube is one of the most popular and demanding services in the Internet today. Thereby, a large portion of this traffic is generated by YouTube's mobile app. While past studies have shown how to monitor browser-based streaming on desktop PCs (e.g., YoMo) or mobile devices (e.g., YoMoApp), streaming in the native app has not been monitored yet. This paper presents an automated framework for monitoring the streaming in YouTube's native app for Android. The concept is based on a wrapper application and the Android Debug Bridge (adb), and can be also extended to automatic measurements with other apps. For YouTube, it allows to collect application-layer streaming data, such as current playtime, buffered playtime, video encoding, and quality switches. These data can be complemented with network measurements on the mobile access link to obtain a holistic view on mobile YouTube streaming on Android devices. In addition to describing the software design and testbed setup, this paper discusses an experimental measurement. This study analyzes the streaming in the native YouTube app and compares it to the streaming from the mobile YouTube website via YoMoApp.
• Evaluation of the Benefits of Variable Segment Durations for Adaptive Streaming Schwarzmann, Susanna; Zinner, Thomas; Sieber, Christian; Geissler, Stefan in The 2nd International Workshop on Quality of Experience Management (2018).
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  HTTP Adaptive Streaming (HAS) is the de-facto standard for video delivery over the Internet. It enables the dynamic adaptation of video quality by splitting the video clip into small segments and providing multiple quality levels per segment. Current HAS streaming services typically utilize segments of equal durations. However, this leads to video encoding overhead as segments have to start with I-frames, independently of the encoded video content. In this paper we evaluate the prospects of variable segment durations, where video segments are aligned to the video characteristics. We evaluate the reduction of the encoding overhead and investigate its impact on the stalling probability using a theoretical model. It turns out that the variable approach outperforms the fixed approach in 86% of the evaluated cases with respect to video stalls.

  @inproceedings{info3-inproceedings-2018-12, abstract = {HTTP Adaptive Streaming (HAS) is the de-facto standard for video delivery over the Internet. It enables the dynamic adaptation of video quality by splitting the video clip into small segments and providing multiple quality levels per segment. Current HAS streaming services typically utilize segments of equal durations. However, this leads to video encoding overhead as segments have to start with I-frames, independently of the encoded video content. In this paper we evaluate the prospects of variable segment durations, where video segments are aligned to the video characteristics. We evaluate the reduction of the encoding overhead and investigate its impact on the stalling probability using a theoretical model. It turns out that the variable approach outperforms the fixed approach in 86% of the evaluated cases with respect to video stalls.}, address = {Sardinia, Italy}, author = {Schwarzmann, Susanna and Zinner, Thomas and Sieber, Christian and Geissler, Stefan}, booktitle = {The 2nd International Workshop on Quality of Experience Management}, keywords = {dfg-sdn}, month = 5, title = {Evaluation of the Benefits of Variable Segment Durations for Adaptive Streaming}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-12 %A Schwarzmann, Susanna %A Zinner, Thomas %A Sieber, Christian %A Geissler, Stefan %B The 2nd International Workshop on Quality of Experience Management %C Sardinia, Italy %D 2018 %T Evaluation of the Benefits of Variable Segment Durations for Adaptive Streaming %X HTTP Adaptive Streaming (HAS) is the de-facto standard for video delivery over the Internet. It enables the dynamic adaptation of video quality by splitting the video clip into small segments and providing multiple quality levels per segment. Current HAS streaming services typically utilize segments of equal durations. However, this leads to video encoding overhead as segments have to start with I-frames, independently of the encoded video content. In this paper we evaluate the prospects of variable segment durations, where video segments are aligned to the video characteristics. We evaluate the reduction of the encoding overhead and investigate its impact on the stalling probability using a theoretical model. It turns out that the variable approach outperforms the fixed approach in 86% of the evaluated cases with respect to video stalls.
• Identification of Delay Thresholds Representing the Perceived Quality of Enterprise Applications Borchert, Kathrin; Lange, Stanislav; Zinner, Thomas; Hirth, Matthias in The 2nd International Workshop on Quality of Experience Management (2018).
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  @inproceedings{info3-inproceedings-2018-11, address = {Sardinia, Italy}, author = {Borchert, Kathrin and Lange, Stanislav and Zinner, Thomas and Hirth, Matthias}, booktitle = {The 2nd International Workshop on Quality of Experience Management}, keywords = {ua-net}, month = 5, title = {Identification of Delay Thresholds Representing the Perceived Quality of Enterprise Applications}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-11 %A Borchert, Kathrin %A Lange, Stanislav %A Zinner, Thomas %A Hirth, Matthias %B The 2nd International Workshop on Quality of Experience Management %C Sardinia, Italy %D 2018 %T Identification of Delay Thresholds Representing the Perceived Quality of Enterprise Applications
• Beauty is in the Eye of the Smartphone Holder - A Data Driven Analysis of YouTube Mobile QoE Wehner, Nikolas; Wassermann, Sarah; Casas, Pedro; Seufert, Michael; Wamser, Florian in 14th International Conference on Network and Service Management (CNSM) (2018).
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  Measuring the Quality of Experience (QoE) undergone by cellular network users has become paramount for cellular ISPs. Given its overwhelming dominance and ever-growing popularity, this paper focuses on the analysis of QoE for YouTube in mobile networks. Using a large-scale dataset of crowdsourced YouTube QoE measurements collected in smartphones with YoMoApp, we analyze the evolution of multiple relevant QoE-related metrics over time for YouTube mobile users. The dataset includes measurements from more than 360 users worldwide, spanning over the last five years. Our data-driven analysis shows a systematic performance and QoE improvement of YouTube in mobile devices over time, accompanied by an improvement of cellular network performance and by an optimization of the YouTube streaming behavior for smartphones.

  @inproceedings{info3-inproceedings-2018-39, abstract = {Measuring the Quality of Experience (QoE) undergone by cellular network users has become paramount for cellular ISPs. Given its overwhelming dominance and ever-growing popularity, this paper focuses on the analysis of QoE for YouTube in mobile networks. Using a large-scale dataset of crowdsourced YouTube QoE measurements collected in smartphones with YoMoApp, we analyze the evolution of multiple relevant QoE-related metrics over time for YouTube mobile users. The dataset includes measurements from more than 360 users worldwide, spanning over the last five years. Our data-driven analysis shows a systematic performance and QoE improvement of YouTube in mobile devices over time, accompanied by an improvement of cellular network performance and by an optimization of the YouTube streaming behavior for smartphones.}, address = {Rome, Italy}, author = {Wehner, Nikolas and Wassermann, Sarah and Casas, Pedro and Seufert, Michael and Wamser, Florian}, booktitle = {14th International Conference on Network and Service Management (CNSM)}, keywords = {can}, month = 11, title = {Beauty is in the Eye of the Smartphone Holder - A Data Driven Analysis of YouTube Mobile QoE}, year = 2018 }

  %0 Conference Paper %1 info3-inproceedings-2018-39 %A Wehner, Nikolas %A Wassermann, Sarah %A Casas, Pedro %A Seufert, Michael %A Wamser, Florian %B 14th International Conference on Network and Service Management (CNSM) %C Rome, Italy %D 2018 %T Beauty is in the Eye of the Smartphone Holder - A Data Driven Analysis of YouTube Mobile QoE %X Measuring the Quality of Experience (QoE) undergone by cellular network users has become paramount for cellular ISPs. Given its overwhelming dominance and ever-growing popularity, this paper focuses on the analysis of QoE for YouTube in mobile networks. Using a large-scale dataset of crowdsourced YouTube QoE measurements collected in smartphones with YoMoApp, we analyze the evolution of multiple relevant QoE-related metrics over time for YouTube mobile users. The dataset includes measurements from more than 360 users worldwide, spanning over the last five years. Our data-driven analysis shows a systematic performance and QoE improvement of YouTube in mobile devices over time, accompanied by an improvement of cellular network performance and by an optimization of the YouTube streaming behavior for smartphones.

• Performance Evaluation of Selective Flow Monitoring in the ONOS Controller Nguyen-Ngoc, Anh; Lange, Stanislav; Zinner, Thomas; Seufert, Michael; Tran-Gia, Phuoc; Aerts, Nieke; Hock, David in 4th International Workshop on Management of SDN and NFV Systems (ManSDN/NFV) (2017).
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  One of the benefits when network operators adopt the Software Defined Networking (SDN) paradigm is the ability to monitor the traffic in the network without an additional network management system. Usually, SDN controllers utilize OpenFlow statistics messages in order to regularly gather information about all flows in the network. However, using the same polling interval for all flows does not take into account the heterogeneity of real world traffic and thus results in an imbalance between monitoring accuracy and control plane overhead. In particular, frequent querying results in a high resource consumption at the controller. This work proposes a Selective Flow Monitoring (SFM) mechanism that allows administrators to classify flows according to their individual requirements in terms of monitoring frequency, e.g., less frequent polling of elephant flows and frequent polling of QoS sensitive VoIP connections. We compare the performance of the SFM mechanism with the default monitoring scheme in a testbed featuring the Open Network Operating System (ONOS) controller. In this context, the CPU utilization of the controller is used as performance indicator. After identifying relevant influence factors like the number of flows and switches in the network, we investigate the viability of the approaches in different scenarios. Finally, we provide guidelines regarding their choice.

  @inproceedings{info3-inproceedings-2017-20, abstract = {One of the benefits when network operators adopt the Software Defined Networking (SDN) paradigm is the ability to monitor the traffic in the network without an additional network management system. Usually, SDN controllers utilize OpenFlow statistics messages in order to regularly gather information about all flows in the network. However, using the same polling interval for all flows does not take into account the heterogeneity of real world traffic and thus results in an imbalance between monitoring accuracy and control plane overhead. In particular, frequent querying results in a high resource consumption at the controller. This work proposes a Selective Flow Monitoring (SFM) mechanism that allows administrators to classify flows according to their individual requirements in terms of monitoring frequency, e.g., less frequent polling of elephant flows and frequent polling of QoS sensitive VoIP connections. We compare the performance of the SFM mechanism with the default monitoring scheme in a testbed featuring the Open Network Operating System (ONOS) controller. In this context, the CPU utilization of the controller is used as performance indicator. After identifying relevant influence factors like the number of flows and switches in the network, we investigate the viability of the approaches in different scenarios. Finally, we provide guidelines regarding their choice.}, address = {Tokio, Japan}, author = {Nguyen-Ngoc, Anh and Lange, Stanislav and Zinner, Thomas and Seufert, Michael and Tran-Gia, Phuoc and Aerts, Nieke and Hock, David}, booktitle = {4th International Workshop on Management of SDN and NFV Systems (ManSDN/NFV)}, keywords = {sys:hidden:inproceedings}, month = 11, title = {Performance Evaluation of Selective Flow Monitoring in the ONOS Controller}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-20 %A Nguyen-Ngoc, Anh %A Lange, Stanislav %A Zinner, Thomas %A Seufert, Michael %A Tran-Gia, Phuoc %A Aerts, Nieke %A Hock, David %B 4th International Workshop on Management of SDN and NFV Systems (ManSDN/NFV) %C Tokio, Japan %D 2017 %T Performance Evaluation of Selective Flow Monitoring in the ONOS Controller %X One of the benefits when network operators adopt the Software Defined Networking (SDN) paradigm is the ability to monitor the traffic in the network without an additional network management system. Usually, SDN controllers utilize OpenFlow statistics messages in order to regularly gather information about all flows in the network. However, using the same polling interval for all flows does not take into account the heterogeneity of real world traffic and thus results in an imbalance between monitoring accuracy and control plane overhead. In particular, frequent querying results in a high resource consumption at the controller. This work proposes a Selective Flow Monitoring (SFM) mechanism that allows administrators to classify flows according to their individual requirements in terms of monitoring frequency, e.g., less frequent polling of elephant flows and frequent polling of QoS sensitive VoIP connections. We compare the performance of the SFM mechanism with the default monitoring scheme in a testbed featuring the Open Network Operating System (ONOS) controller. In this context, the CPU utilization of the controller is used as performance indicator. After identifying relevant influence factors like the number of flows and switches in the network, we investigate the viability of the approaches in different scenarios. Finally, we provide guidelines regarding their choice.
• A Multi-Objective Heuristic for the Optimization of Virtual Network Function Chain Placement Lange, Stanislav; Grigorjew, Alexej; Zinner, Thomas; Tran-Gia, Phuoc; Jarschel, Michael in 29th International Teletraffic Congress (ITC) (2017).
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  @inproceedings{info3-inproceedings-2017-16, author = {Lange, Stanislav and Grigorjew, Alexej and Zinner, Thomas and Tran-Gia, Phuoc and Jarschel, Michael}, booktitle = {29th International Teletraffic Congress (ITC)}, keywords = {ngn}, month = 9, title = {A Multi-Objective Heuristic for the Optimization of Virtual Network Function Chain Placement}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-16 %A Lange, Stanislav %A Grigorjew, Alexej %A Zinner, Thomas %A Tran-Gia, Phuoc %A Jarschel, Michael %B 29th International Teletraffic Congress (ITC) %D 2017 %T A Multi-Objective Heuristic for the Optimization of Virtual Network Function Chain Placement
• Keep Calm and Don’t Switch: About the Relationship Between Switches and Quality in HAS Moldovan, Christian; Hagn, Korbinian; Sieber, Christian; Kellerer, Wolfgang; Hoßfeld, Tobias in 29th International Teletraffic Congress (ITC 29) (2017). 6.
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  Video streaming has established itself as the main method to consume multimedia content on the Internet. The most widespread technique is HTTP Adaptive Streaming which is used by large video service platforms such as YouTube and Netflix. In order to guarantee a high QoE, different adaptation strategies have been developed that lead to different video playout patterns. While some strategies may be more aggressive than others and often adapt the video quality, it is not clear which strategy is the best. In this paper, we want to identify the trade-off between the av- erage video quality and switches in the quality during playout. We do this with a user-centric view and try to optimize the adaptation depending on the user preference with a quadratic program. This work allows us to put existing and future video adaptation algorithms in perspective with respect to user preferences. Our results show that the video quality can already be increased greatly by allowing few switches while more switches lead to diminishing gains. This is a novel discovery that is important for user-centric QoE-management which is of high interest for ISPs and video service providers.

  @inproceedings{info3-inproceedings-2017-26, abstract = {Video streaming has established itself as the main method to consume multimedia content on the Internet. The most widespread technique is HTTP Adaptive Streaming which is used by large video service platforms such as YouTube and Netflix. In order to guarantee a high QoE, different adaptation strategies have been developed that lead to different video playout patterns. While some strategies may be more aggressive than others and often adapt the video quality, it is not clear which strategy is the best. In this paper, we want to identify the trade-off between the av- erage video quality and switches in the quality during playout. We do this with a user-centric view and try to optimize the adaptation depending on the user preference with a quadratic program. This work allows us to put existing and future video adaptation algorithms in perspective with respect to user preferences. Our results show that the video quality can already be increased greatly by allowing few switches while more switches lead to diminishing gains. This is a novel discovery that is important for user-centric QoE-management which is of high interest for ISPs and video service providers.}, address = {Genoa, Italy}, author = {Moldovan, Christian and Hagn, Korbinian and Sieber, Christian and Kellerer, Wolfgang and Hoßfeld, Tobias}, booktitle = {29th International Teletraffic Congress (ITC 29)}, keywords = {video-quality}, month = 9, pages = 6, title = {Keep Calm and Don’t Switch: About the Relationship Between Switches and Quality in HAS}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-26 %A Moldovan, Christian %A Hagn, Korbinian %A Sieber, Christian %A Kellerer, Wolfgang %A Hoßfeld, Tobias %B 29th International Teletraffic Congress (ITC 29) %C Genoa, Italy %D 2017 %P 6 %T Keep Calm and Don’t Switch: About the Relationship Between Switches and Quality in HAS %X Video streaming has established itself as the main method to consume multimedia content on the Internet. The most widespread technique is HTTP Adaptive Streaming which is used by large video service platforms such as YouTube and Netflix. In order to guarantee a high QoE, different adaptation strategies have been developed that lead to different video playout patterns. While some strategies may be more aggressive than others and often adapt the video quality, it is not clear which strategy is the best. In this paper, we want to identify the trade-off between the av- erage video quality and switches in the quality during playout. We do this with a user-centric view and try to optimize the adaptation depending on the user preference with a quadratic program. This work allows us to put existing and future video adaptation algorithms in perspective with respect to user preferences. Our results show that the video quality can already be increased greatly by allowing few switches while more switches lead to diminishing gains. This is a novel discovery that is important for user-centric QoE-management which is of high interest for ISPs and video service providers.
• The BitTorrent Peer Collector Problem Lareida, Andri; Hoßfeld, Tobias; Stiller, Burkhard in IFIP/IEEE International Symposium on Integrated Network Management (2017).
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  @inproceedings{info3-inproceedings-2017-24, address = {Lisbon, Portugal}, author = {Lareida, Andri and Hoßfeld, Tobias and Stiller, Burkhard}, booktitle = {IFIP/IEEE International Symposium on Integrated Network Management}, keywords = {sys:hidden:inproceedings}, title = {The BitTorrent Peer Collector Problem}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-24 %A Lareida, Andri %A Hoßfeld, Tobias %A Stiller, Burkhard %B IFIP/IEEE International Symposium on Integrated Network Management %C Lisbon, Portugal %D 2017 %T The BitTorrent Peer Collector Problem
• Betas: Deriving Quantiles from MOS-QoS Relations of IQX Models for QoE Management Hoßfeld, Tobias; Fiedler, Markus; Gustafsson, Jörgen in IFIP/IEEE International Workshop on Quality of Experience Management (QoE-Management) (2017).
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  @inproceedings{info3-inproceedings-2017-25, address = {Lisbon, Portugal}, author = {Hoßfeld, Tobias and Fiedler, Markus and Gustafsson, Jörgen}, booktitle = {IFIP/IEEE International Workshop on Quality of Experience Management (QoE-Management)}, keywords = {sys:hidden:inproceedings}, title = {Betas: Deriving Quantiles from MOS-QoS Relations of IQX Models for QoE Management}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-25 %A Hoßfeld, Tobias %A Fiedler, Markus %A Gustafsson, Jörgen %B IFIP/IEEE International Workshop on Quality of Experience Management (QoE-Management) %C Lisbon, Portugal %D 2017 %T Betas: Deriving Quantiles from MOS-QoS Relations of IQX Models for QoE Management
• No Silver Bullet: QoE Metrics, QoE Fairness, and User Diversity in the Context of QoE Management Hoßfeld, Tobias; Heegaard, Poul E.; Skorin-Kapov, Lea; Varela, Martin in 9th International Conference on Quality of Multimedia Experience (QoMEX 2017) (2017).
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  @inproceedings{info3-inproceedings-2017-23, address = {Erfurt, Germany}, author = {Hoßfeld, Tobias and Heegaard, Poul E. and Skorin-Kapov, Lea and Varela, Martin}, booktitle = {9th International Conference on Quality of Multimedia Experience (QoMEX 2017)}, keywords = {sys:hidden:inproceedings}, title = {No Silver Bullet: QoE Metrics, QoE Fairness, and User Diversity in the Context of QoE Management}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-23 %A Hoßfeld, Tobias %A Heegaard, Poul E. %A Skorin-Kapov, Lea %A Varela, Martin %B 9th International Conference on Quality of Multimedia Experience (QoMEX 2017) %C Erfurt, Germany %D 2017 %T No Silver Bullet: QoE Metrics, QoE Fairness, and User Diversity in the Context of QoE Management
• Predicting QoE in Cellular Networks using Machine Learning and in-Smartphone Measurements Casas, Pedro; D’Alconzo, Alessandro; Wamser, Florian; Seufert, Michael; Gardlo, Bruno; Schwind, Anika; Tran-Gia, Phuoc; Schatz, Raimund in 9th International Conference on Quality of Multimedia Experience (QoMEX) (2017).
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  Monitoring the Quality of Experience (QoE) undergone by cellular network customers has become paramount for cellular ISPs, who need to ensure high quality levels to limit customer churn due to quality dissatisfaction. This paper tackles the problem of QoE monitoring, assessment and prediction in cellular networks, relying on end-user device (i.e., smartphone) QoS passive traffic measurements and QoE crowdsourced feedback. We conceive different QoE assessment models based on supervised machine learning techniques, which are capable to predict the QoE experienced by the end user of popular smartphone apps (e.g., YouTube and Facebook), using as input the passive in-device measurements. Using a rich QoE dataset derived from field trials in operational cellular networks, we benchmark the performance of multiple machine learning based predictors, and construct a decision-tree based model which is capable to predict the per-user overall experience and service acceptability with a success rate of 91% and 98% respectively. To the best of our knowledge, this is the first paper using end-user, in-device passive measurements and machine learning models to predict the QoE of smartphone users in operational cellular networks.

  @inproceedings{info3-inproceedings-2017-10, abstract = {Monitoring the Quality of Experience (QoE) undergone by cellular network customers has become paramount for cellular ISPs, who need to ensure high quality levels to limit customer churn due to quality dissatisfaction. This paper tackles the problem of QoE monitoring, assessment and prediction in cellular networks, relying on end-user device (i.e., smartphone) QoS passive traffic measurements and QoE crowdsourced feedback. We conceive different QoE assessment models based on supervised machine learning techniques, which are capable to predict the QoE experienced by the end user of popular smartphone apps (e.g., YouTube and Facebook), using as input the passive in-device measurements. Using a rich QoE dataset derived from field trials in operational cellular networks, we benchmark the performance of multiple machine learning based predictors, and construct a decision-tree based model which is capable to predict the per-user overall experience and service acceptability with a success rate of 91% and 98% respectively. To the best of our knowledge, this is the first paper using end-user, in-device passive measurements and machine learning models to predict the QoE of smartphone users in operational cellular networks.}, address = {Erfurt, Germany}, author = {Casas, Pedro and D'Alconzo, Alessandro and Wamser, Florian and Seufert, Michael and Gardlo, Bruno and Schwind, Anika and Tran-Gia, Phuoc and Schatz, Raimund}, booktitle = {9th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {can}, month = 5, title = {Predicting QoE in Cellular Networks using Machine Learning and in-Smartphone Measurements}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-10 %A Casas, Pedro %A D'Alconzo, Alessandro %A Wamser, Florian %A Seufert, Michael %A Gardlo, Bruno %A Schwind, Anika %A Tran-Gia, Phuoc %A Schatz, Raimund %B 9th International Conference on Quality of Multimedia Experience (QoMEX) %C Erfurt, Germany %D 2017 %T Predicting QoE in Cellular Networks using Machine Learning and in-Smartphone Measurements %X Monitoring the Quality of Experience (QoE) undergone by cellular network customers has become paramount for cellular ISPs, who need to ensure high quality levels to limit customer churn due to quality dissatisfaction. This paper tackles the problem of QoE monitoring, assessment and prediction in cellular networks, relying on end-user device (i.e., smartphone) QoS passive traffic measurements and QoE crowdsourced feedback. We conceive different QoE assessment models based on supervised machine learning techniques, which are capable to predict the QoE experienced by the end user of popular smartphone apps (e.g., YouTube and Facebook), using as input the passive in-device measurements. Using a rich QoE dataset derived from field trials in operational cellular networks, we benchmark the performance of multiple machine learning based predictors, and construct a decision-tree based model which is capable to predict the per-user overall experience and service acceptability with a success rate of 91% and 98% respectively. To the best of our knowledge, this is the first paper using end-user, in-device passive measurements and machine learning models to predict the QoE of smartphone users in operational cellular networks.
• On Use of Crowdsourcing for H.264/AVC and H.265/HEVC Video Quality Evaluation Zach, Ondrej; Seufert, Michael; Hirth, Matthias; Slanina, Martin; Tran-Gia, Phuoc in Radioelektronika (2017).
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  Crowdsourcing has become a popular method in the field of video quality evaluation. Gathering the opinion of the users using crowdsourcing is quick and relatively cheap but such a study has to be designed very carefully in order to give relevant results. So far, the majority of the QoE studies using crowdsourcing has been focusing on the performance of H.264/AVC algorithm in different situations (such as encoder settings, stalling effects, etc). Modern video coding methods, however, are only rarely tested using the crowdsourcing approach. We designed a study comparing the performance of both H.264/AVC and H.265/HEVC standards in the crowdsourcing environment. We deal with the possibilities of delivering and presenting the HEVC encoded content to the participants of the crowdsourcing study and potential challenges. Finally, the study was performed using Microworkers platform and gathered results are then compared with three different objective video quality metrics.

  @inproceedings{info3-inproceedings-2017-7, abstract = {Crowdsourcing has become a popular method in the field of video quality evaluation. Gathering the opinion of the users using crowdsourcing is quick and relatively cheap but such a study has to be designed very carefully in order to give relevant results. So far, the majority of the QoE studies using crowdsourcing has been focusing on the performance of H.264/AVC algorithm in different situations (such as encoder settings, stalling effects, etc). Modern video coding methods, however, are only rarely tested using the crowdsourcing approach. We designed a study comparing the performance of both H.264/AVC and H.265/HEVC standards in the crowdsourcing environment. We deal with the possibilities of delivering and presenting the HEVC encoded content to the participants of the crowdsourcing study and potential challenges. Finally, the study was performed using Microworkers platform and gathered results are then compared with three different objective video quality metrics.}, address = {Brno, Czech Republic}, author = {Zach, Ondrej and Seufert, Michael and Hirth, Matthias and Slanina, Martin and Tran-Gia, Phuoc}, booktitle = {Radioelektronika}, keywords = {fia}, month = 4, title = {On Use of Crowdsourcing for H.264/AVC and H.265/HEVC Video Quality Evaluation}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-7 %A Zach, Ondrej %A Seufert, Michael %A Hirth, Matthias %A Slanina, Martin %A Tran-Gia, Phuoc %B Radioelektronika %C Brno, Czech Republic %D 2017 %T On Use of Crowdsourcing for H.264/AVC and H.265/HEVC Video Quality Evaluation %X Crowdsourcing has become a popular method in the field of video quality evaluation. Gathering the opinion of the users using crowdsourcing is quick and relatively cheap but such a study has to be designed very carefully in order to give relevant results. So far, the majority of the QoE studies using crowdsourcing has been focusing on the performance of H.264/AVC algorithm in different situations (such as encoder settings, stalling effects, etc). Modern video coding methods, however, are only rarely tested using the crowdsourcing approach. We designed a study comparing the performance of both H.264/AVC and H.265/HEVC standards in the crowdsourcing environment. We deal with the possibilities of delivering and presenting the HEVC encoded content to the participants of the crowdsourcing study and potential challenges. Finally, the study was performed using Microworkers platform and gathered results are then compared with three different objective video quality metrics.
• An AAL-Oriented Measurement-based Evaluation of Different HTTP-based Data Transport Protocols Zinner, Thomas; Geissler, Stefan; Helmschrott, Fabian; Spinsante, Susanna; Braeken, An in International Workshop on Protocols, Applications and Platforms for Enhanced Living Environments (2017).
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  A key requirement for Active and Assisted Living (AAL) environments is the exchange of data between different communication endpoints to support wide range of services and applications. Used communication protocols need to support the bidirectional flow of information and have to be optimized with regard to security or latency constraints. To address these issues, RESTful approaches have recently gained much attention from the community. In this context, different application layer transport protocols can be used to realize the required data exchange. Besides HTTP/1.1, developed and standardized in the 1990s, new protocols like HTTP/2 and the QUIC transfer protocol my be suitable candidates. The impact of the different protocols on the overall performance for web and AAL services is still an open research question. This paper narrows this gap by conducting a measurement-based comparison of the three described protocols with regard to their performance in terms of web page loading times for Google web services.

  @inproceedings{info3-inproceedings-2017-5, abstract = {A key requirement for Active and Assisted Living (AAL) environments is the exchange of data between different communication endpoints to support wide range of services and applications. Used communication protocols need to support the bidirectional flow of information and have to be optimized with regard to security or latency constraints. To address these issues, RESTful approaches have recently gained much attention from the community. In this context, different application layer transport protocols can be used to realize the required data exchange. Besides HTTP/1.1, developed and standardized in the 1990s, new protocols like HTTP/2 and the QUIC transfer protocol my be suitable candidates. The impact of the different protocols on the overall performance for web and AAL services is still an open research question. This paper narrows this gap by conducting a measurement-based comparison of the three described protocols with regard to their performance in terms of web page loading times for Google web services.}, author = {Zinner, Thomas and Geissler, Stefan and Helmschrott, Fabian and Spinsante, Susanna and Braeken, An}, booktitle = {International Workshop on Protocols, Applications and Platforms for Enhanced Living Environments}, keywords = {ngn}, month = 2, title = {An AAL-Oriented Measurement-based Evaluation of Different HTTP-based Data Transport Protocols}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-5 %A Zinner, Thomas %A Geissler, Stefan %A Helmschrott, Fabian %A Spinsante, Susanna %A Braeken, An %B International Workshop on Protocols, Applications and Platforms for Enhanced Living Environments %D 2017 %T An AAL-Oriented Measurement-based Evaluation of Different HTTP-based Data Transport Protocols %X A key requirement for Active and Assisted Living (AAL) environments is the exchange of data between different communication endpoints to support wide range of services and applications. Used communication protocols need to support the bidirectional flow of information and have to be optimized with regard to security or latency constraints. To address these issues, RESTful approaches have recently gained much attention from the community. In this context, different application layer transport protocols can be used to realize the required data exchange. Besides HTTP/1.1, developed and standardized in the 1990s, new protocols like HTTP/2 and the QUIC transfer protocol my be suitable candidates. The impact of the different protocols on the overall performance for web and AAL services is still an open research question. This paper narrows this gap by conducting a measurement-based comparison of the three described protocols with regard to their performance in terms of web page loading times for Google web services.
• Performance Evaluation of Video Streaming Service Chains in Softwarized 5G Networks with Task Graph Reduction Loh, Frank; Burger, Valentin; Wamser, Florian; Tran-Gia, Phuoc; Schembra, Giovanni; Rametta, Corrado in 29th International Teletraffic Congress (ITC) (2017).
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  @inproceedings{info3-inproceedings-2017-18, author = {Loh, Frank and Burger, Valentin and Wamser, Florian and Tran-Gia, Phuoc and Schembra, Giovanni and Rametta, Corrado}, booktitle = {29th International Teletraffic Congress (ITC)}, keywords = {can}, month = 9, title = {Performance Evaluation of Video Streaming Service Chains in Softwarized 5G Networks with Task Graph Reduction}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-18 %A Loh, Frank %A Burger, Valentin %A Wamser, Florian %A Tran-Gia, Phuoc %A Schembra, Giovanni %A Rametta, Corrado %B 29th International Teletraffic Congress (ITC) %D 2017 %T Performance Evaluation of Video Streaming Service Chains in Softwarized 5G Networks with Task Graph Reduction
• Performance Assessment of Cloud Migrations from Network and Application Point of View Iffländer, Lukas; Wamser, Florian; Metter, Christopher; Tran-Gia, Phuoc; Kounev, Samuel in Proceedings of 9th EAI International Conference on Mobile Networks and Management (MONAMI 2017) (2017).
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  @inproceedings{info3-inproceedings-2017-22, address = {Melbourne, Australia}, author = {Iffländer, Lukas and Wamser, Florian and Metter, Christopher and Tran-Gia, Phuoc and Kounev, Samuel}, booktitle = {Proceedings of 9th EAI International Conference on Mobile Networks and Management (MONAMI 2017)}, keywords = {can}, month = 12, title = {Performance Assessment of Cloud Migrations from Network and Application Point of View}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-22 %A Iffländer, Lukas %A Wamser, Florian %A Metter, Christopher %A Tran-Gia, Phuoc %A Kounev, Samuel %B Proceedings of 9th EAI International Conference on Mobile Networks and Management (MONAMI 2017) %C Melbourne, Australia %D 2017 %T Performance Assessment of Cloud Migrations from Network and Application Point of View
• Impact of Task Recommendation Systems in Crowdsourcing Platforms Borchert, Kathrin; Hirth, Matthias; Schnitzer, Steffen; Rensing, Christoph in Workshop on Responsible Recommendation at RecSys 2017 (2017).
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  @inproceedings{info3-inproceedings-2017-17, address = {Como, Italy}, author = {Borchert, Kathrin and Hirth, Matthias and Schnitzer, Steffen and Rensing, Christoph}, booktitle = {Workshop on Responsible Recommendation at RecSys 2017}, keywords = {sys:hidden:inproceedings}, month = 8, title = {Impact of Task Recommendation Systems in Crowdsourcing Platforms}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-17 %A Borchert, Kathrin %A Hirth, Matthias %A Schnitzer, Steffen %A Rensing, Christoph %B Workshop on Responsible Recommendation at RecSys 2017 %C Como, Italy %D 2017 %T Impact of Task Recommendation Systems in Crowdsourcing Platforms
• Automated Decision Making based on Pareto Frontiers in the Context of Service Placement in Networks Seufert, Michael; Lange, Stanislav; Meixner, Markus in 29th International Teletraffic Congress (ITC) (2017).
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  Virtualization paradigms like cloud computing, software defined networking (SDN), and network functions virtualization (NFV) provide advantages with respect to aspects like flexibility, costs, and scalability. However, management and orchestration of the resulting networks also introduce new challenges. The placement of services, such as virtual machines~(VMs), virtualized network functions~(VNFs), or SDN controllers, is a multi-objective optimization task that confronts operators with a multitude of possible solutions that are incomparable among each other. The goal of this work is to investigate mechanisms that enable automated decision making between such multi-dimensional solutions. To this end, we investigate techniques from the domain of multi-attribute decision making that aggregate the performance of placements to a single numeric score. A comparison between resulting rankings of placements shows that many techniques produce similar results. Hence, placements that achieve good rankings according to many approaches might be viable candidates in the context of automated decision making. In order to illustrate the functionality of the different scoring mechanisms, we perform a case study on a single network graph and a fixed number of objectives and service instances. Additionally, we present aggregated results from broad evaluations on the Internet Topology Zoo and a larger number of objectives as well as varying numbers of service instances. These allow making more reliable statements about the mechanisms' performance and agreement.

  @inproceedings{info3-article-2017-6, abstract = {Virtualization paradigms like cloud computing, software defined networking (SDN), and network functions virtualization (NFV) provide advantages with respect to aspects like flexibility, costs, and scalability. However, management and orchestration of the resulting networks also introduce new challenges. The placement of services, such as virtual machines (VMs), virtualized network functions (VNFs), or SDN controllers, is a multi-objective optimization task that confronts operators with a multitude of possible solutions that are incomparable among each other. The goal of this work is to investigate mechanisms that enable automated decision making between such multi-dimensional solutions. To this end, we investigate techniques from the domain of multi-attribute decision making that aggregate the performance of placements to a single numeric score. A comparison between resulting rankings of placements shows that many techniques produce similar results. Hence, placements that achieve good rankings according to many approaches might be viable candidates in the context of automated decision making. In order to illustrate the functionality of the different scoring mechanisms, we perform a case study on a single network graph and a fixed number of objectives and service instances. Additionally, we present aggregated results from broad evaluations on the Internet Topology Zoo and a larger number of objectives as well as varying numbers of service instances. These allow making more reliable statements about the mechanisms' performance and agreement.}, address = {Genoa, Italy}, author = {Seufert, Michael and Lange, Stanislav and Meixner, Markus}, booktitle = {29th International Teletraffic Congress (ITC)}, keywords = {ngn}, month = 9, title = {Automated Decision Making based on Pareto Frontiers in the Context of Service Placement in Networks}, year = 2017 }

  %0 Conference Paper %1 info3-article-2017-6 %A Seufert, Michael %A Lange, Stanislav %A Meixner, Markus %B 29th International Teletraffic Congress (ITC) %C Genoa, Italy %D 2017 %T Automated Decision Making based on Pareto Frontiers in the Context of Service Placement in Networks %X Virtualization paradigms like cloud computing, software defined networking (SDN), and network functions virtualization (NFV) provide advantages with respect to aspects like flexibility, costs, and scalability. However, management and orchestration of the resulting networks also introduce new challenges. The placement of services, such as virtual machines~(VMs), virtualized network functions~(VNFs), or SDN controllers, is a multi-objective optimization task that confronts operators with a multitude of possible solutions that are incomparable among each other. The goal of this work is to investigate mechanisms that enable automated decision making between such multi-dimensional solutions. To this end, we investigate techniques from the domain of multi-attribute decision making that aggregate the performance of placements to a single numeric score. A comparison between resulting rankings of placements shows that many techniques produce similar results. Hence, placements that achieve good rankings according to many approaches might be viable candidates in the context of automated decision making. In order to illustrate the functionality of the different scoring mechanisms, we perform a case study on a single network graph and a fixed number of objectives and service instances. Additionally, we present aggregated results from broad evaluations on the Internet Topology Zoo and a larger number of objectives as well as varying numbers of service instances. These allow making more reliable statements about the mechanisms' performance and agreement.
• Concept and Implementation of Video QoE Measurements in a Mobile Broadband Testbed Schwind, Anika; Seufert, Michael; Alay, Özgü; Casas, Pedro; Tran-Gia, Phuoc; Wamser, Florian in IEEE/IFIP Workshop on Mobile Network Measurement (MNM’17) (2017).
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  The MONROE testbed enables the objective performance assessment of MBB networks from the end-user perspective, using highly distributed measurements from fixed and mobile nodes. To quantify the performance of MBB networks for popular Internet services from a user-centric perspective, dedicated tools are needed. In this paper we extend the MONROE testbed to the Quality of Experience (QoE) domain, presenting the design and implementation of a QoE-capable measurement tool for YouTube video streaming. The measurement concept is based on emulating a virtual end-user device requesting video streams, which are then monitored at the network and application layers, on the basis of QoE-relevant features. The initial measurements conducted in the MONROE testbed and reported in this paper demonstrate the applicability of the implemented measurement concept.

  @inproceedings{info3-inproceedings-2017-15, abstract = {The MONROE testbed enables the objective performance assessment of MBB networks from the end-user perspective, using highly distributed measurements from fixed and mobile nodes. To quantify the performance of MBB networks for popular Internet services from a user-centric perspective, dedicated tools are needed. In this paper we extend the MONROE testbed to the Quality of Experience (QoE) domain, presenting the design and implementation of a QoE-capable measurement tool for YouTube video streaming. The measurement concept is based on emulating a virtual end-user device requesting video streams, which are then monitored at the network and application layers, on the basis of QoE-relevant features. The initial measurements conducted in the MONROE testbed and reported in this paper demonstrate the applicability of the implemented measurement concept.}, address = {Dublin, Ireland}, author = {Schwind, Anika and Seufert, Michael and Alay, Özgü and Casas, Pedro and Tran-Gia, Phuoc and Wamser, Florian}, booktitle = {IEEE/IFIP Workshop on Mobile Network Measurement (MNM’17)}, keywords = {vnf_qoe_cloud}, month = 6, title = {Concept and Implementation of Video QoE Measurements in a Mobile Broadband Testbed}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-15 %A Schwind, Anika %A Seufert, Michael %A Alay, Özgü %A Casas, Pedro %A Tran-Gia, Phuoc %A Wamser, Florian %B IEEE/IFIP Workshop on Mobile Network Measurement (MNM’17) %C Dublin, Ireland %D 2017 %T Concept and Implementation of Video QoE Measurements in a Mobile Broadband Testbed %X The MONROE testbed enables the objective performance assessment of MBB networks from the end-user perspective, using highly distributed measurements from fixed and mobile nodes. To quantify the performance of MBB networks for popular Internet services from a user-centric perspective, dedicated tools are needed. In this paper we extend the MONROE testbed to the Quality of Experience (QoE) domain, presenting the design and implementation of a QoE-capable measurement tool for YouTube video streaming. The measurement concept is based on emulating a virtual end-user device requesting video streams, which are then monitored at the network and application layers, on the basis of QoE-relevant features. The initial measurements conducted in the MONROE testbed and reported in this paper demonstrate the applicability of the implemented measurement concept.
• EdgeNetworkCloudSim: Placement of Service Chains in Edge Clouds Using NetworkCloudSim Seufert, Michael; Kamneng Kwam, Brice; Wamser, Florian; Tran-Gia, Phuoc in 1st IEEE International Workshop on Network Programmability - From the Data Center to the Ground (NetFoG) (2017).
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  Edge cloud computing is a trending paradigm, which extends cloud computing by additionally utilizing computing resources at the network edge, e.g., at mobile base stations. Especially personalized services can be instantiated or migrated close to end users, which improves the latency and supports user mobility. However, the placement of the service chains is crucial for the performance of the services and the energy consumption of the edge cloud platform, and appropriate algorithms have to be designed. To support the simulative performance evaluation of such algorithms, EdgeNetworkCloudSim was developed. It is an extension of NetworkCloudSim, and allows to simulate and evaluate the orchestration and consolidation of service chains in an edge network cloud.

  @inproceedings{info3-inproceedings-2017-12, abstract = {Edge cloud computing is a trending paradigm, which extends cloud computing by additionally utilizing computing resources at the network edge, e.g., at mobile base stations. Especially personalized services can be instantiated or migrated close to end users, which improves the latency and supports user mobility. However, the placement of the service chains is crucial for the performance of the services and the energy consumption of the edge cloud platform, and appropriate algorithms have to be designed. To support the simulative performance evaluation of such algorithms, EdgeNetworkCloudSim was developed. It is an extension of NetworkCloudSim, and allows to simulate and evaluate the orchestration and consolidation of service chains in an edge network cloud.}, address = {Bologna, Italy}, author = {Seufert, Michael and Kamneng Kwam, Brice and Wamser, Florian and Tran-Gia, Phuoc}, booktitle = {1st IEEE International Workshop on Network Programmability - From the Data Center to the Ground (NetFoG)}, keywords = {can}, month = 7, title = {EdgeNetworkCloudSim: Placement of Service Chains in Edge Clouds Using NetworkCloudSim}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-12 %A Seufert, Michael %A Kamneng Kwam, Brice %A Wamser, Florian %A Tran-Gia, Phuoc %B 1st IEEE International Workshop on Network Programmability - From the Data Center to the Ground (NetFoG) %C Bologna, Italy %D 2017 %T EdgeNetworkCloudSim: Placement of Service Chains in Edge Clouds Using NetworkCloudSim %X Edge cloud computing is a trending paradigm, which extends cloud computing by additionally utilizing computing resources at the network edge, e.g., at mobile base stations. Especially personalized services can be instantiated or migrated close to end users, which improves the latency and supports user mobility. However, the placement of the service chains is crucial for the performance of the services and the energy consumption of the edge cloud platform, and appropriate algorithms have to be designed. To support the simulative performance evaluation of such algorithms, EdgeNetworkCloudSim was developed. It is an extension of NetworkCloudSim, and allows to simulate and evaluate the orchestration and consolidation of service chains in an edge network cloud.
• Collecting Subjective Ratings in Enterprise Environments Borchert, Kathrin; Hirth, Matthias; Zinner, Thomas; Göritz, Anja in 9th International Conference on Quality of Multimedia Experience (QoMEX) (2017).
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  @inproceedings{info3-inproceedings-2017-14, address = {Erfurt, Germany}, author = {Borchert, Kathrin and Hirth, Matthias and Zinner, Thomas and Göritz, Anja}, booktitle = {9th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ua-net}, month = 5, title = {Collecting Subjective Ratings in Enterprise Environments}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-14 %A Borchert, Kathrin %A Hirth, Matthias %A Zinner, Thomas %A Göritz, Anja %B 9th International Conference on Quality of Multimedia Experience (QoMEX) %C Erfurt, Germany %D 2017 %T Collecting Subjective Ratings in Enterprise Environments
• Server and Content Selection for MPEG DASH Video Streaming with Client Information Wamser, Florian; Höfner, Steffen; Seufert, Michael; Tran-Gia, Phuoc in ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) (2017).
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  In HTTP adaptive streaming (HAS), such as MPEG DASH, the video is split into chunks and is available in different quality levels. If the video chunks are stored or cached on different servers to deal with the high load in the network and the Quality of Experience (QoE) requirements of the users, the problem of content selection arises. In this paper, we evaluate client-side algorithms for dynamically selecting an appropriate content server during DASH video streaming. We present three algorithms with which the DASH client itself can determine the most appropriate server based on client-specific metrics, like actual latency or bandwidth to the content servers. We evaluate and discuss the proposed algorithms with respect to the resulting DASH streaming behavior in terms of buffer levels and quality level selection.

  @inproceedings{info3-article-2017-3, abstract = {In HTTP adaptive streaming (HAS), such as MPEG DASH, the video is split into chunks and is available in different quality levels. If the video chunks are stored or cached on different servers to deal with the high load in the network and the Quality of Experience (QoE) requirements of the users, the problem of content selection arises. In this paper, we evaluate client-side algorithms for dynamically selecting an appropriate content server during DASH video streaming. We present three algorithms with which the DASH client itself can determine the most appropriate server based on client-specific metrics, like actual latency or bandwidth to the content servers. We evaluate and discuss the proposed algorithms with respect to the resulting DASH streaming behavior in terms of buffer levels and quality level selection.}, address = {Los Angeles, CA, USA}, author = {Wamser, Florian and Höfner, Steffen and Seufert, Michael and Tran-Gia, Phuoc}, booktitle = {ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE)}, keywords = {can}, month = 8, title = {Server and Content Selection for MPEG DASH Video Streaming with Client Information}, year = 2017 }

  %0 Conference Paper %1 info3-article-2017-3 %A Wamser, Florian %A Höfner, Steffen %A Seufert, Michael %A Tran-Gia, Phuoc %B ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) %C Los Angeles, CA, USA %D 2017 %T Server and Content Selection for MPEG DASH Video Streaming with Client Information %X In HTTP adaptive streaming (HAS), such as MPEG DASH, the video is split into chunks and is available in different quality levels. If the video chunks are stored or cached on different servers to deal with the high load in the network and the Quality of Experience (QoE) requirements of the users, the problem of content selection arises. In this paper, we evaluate client-side algorithms for dynamically selecting an appropriate content server during DASH video streaming. We present three algorithms with which the DASH client itself can determine the most appropriate server based on client-specific metrics, like actual latency or bandwidth to the content servers. We evaluate and discuss the proposed algorithms with respect to the resulting DASH streaming behavior in terms of buffer levels and quality level selection.
• Applicability and Limitations of a Simple WiFi Hotspot Model for Cities Seufert, Michael; Moldovan, Christian; Burger, Valentin; Hoßfeld, Tobias in 13th International Conference on Network and Service Management (CNSM) (2017).
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  Offloading mobile Internet data via WiFi has emerged as an omnipresent trend. WiFi networks are already widely deployed by many private and public institutions (e.g., libraries, cafes, restaurants) but also by commercial services to provide alternative Internet access for their customers and to mitigate the load on mobile networks. Moreover, smart cities start to install WiFi infrastructure for current and future civic services, e.g., based on sensor networks or the Internet of Things. A simple model for the distribution of WiFi hotspots in an urban environment is presented. The hotspot locations are modeled with a uniform distribution of the angle and an exponential distribution of the distance, which is truncated to the city limits. We compare the characteristics of this model in detail to the real distributions. Moreover, we show the applicability and the limitations of this model, and the results suggest that the model can be used in scenarios, which do not require an accurate spatial collocation of the hotspots, such as offloading potential, coverage, or signal strength.

  @inproceedings{info3-inproceedings-2017-19, abstract = {Offloading mobile Internet data via WiFi has emerged as an omnipresent trend. WiFi networks are already widely deployed by many private and public institutions (e.g., libraries, cafes, restaurants) but also by commercial services to provide alternative Internet access for their customers and to mitigate the load on mobile networks. Moreover, smart cities start to install WiFi infrastructure for current and future civic services, e.g., based on sensor networks or the Internet of Things. A simple model for the distribution of WiFi hotspots in an urban environment is presented. The hotspot locations are modeled with a uniform distribution of the angle and an exponential distribution of the distance, which is truncated to the city limits. We compare the characteristics of this model in detail to the real distributions. Moreover, we show the applicability and the limitations of this model, and the results suggest that the model can be used in scenarios, which do not require an accurate spatial collocation of the hotspots, such as offloading potential, coverage, or signal strength.}, address = {Tokio, Japan}, author = {Seufert, Michael and Moldovan, Christian and Burger, Valentin and Hoßfeld, Tobias}, booktitle = {13th International Conference on Network and Service Management (CNSM)}, keywords = {can}, month = 11, title = {Applicability and Limitations of a Simple WiFi Hotspot Model for Cities}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-19 %A Seufert, Michael %A Moldovan, Christian %A Burger, Valentin %A Hoßfeld, Tobias %B 13th International Conference on Network and Service Management (CNSM) %C Tokio, Japan %D 2017 %T Applicability and Limitations of a Simple WiFi Hotspot Model for Cities %X Offloading mobile Internet data via WiFi has emerged as an omnipresent trend. WiFi networks are already widely deployed by many private and public institutions (e.g., libraries, cafes, restaurants) but also by commercial services to provide alternative Internet access for their customers and to mitigate the load on mobile networks. Moreover, smart cities start to install WiFi infrastructure for current and future civic services, e.g., based on sensor networks or the Internet of Things. A simple model for the distribution of WiFi hotspots in an urban environment is presented. The hotspot locations are modeled with a uniform distribution of the angle and an exponential distribution of the distance, which is truncated to the city limits. We compare the characteristics of this model in detail to the real distributions. Moreover, we show the applicability and the limitations of this model, and the results suggest that the model can be used in scenarios, which do not require an accurate spatial collocation of the hotspots, such as offloading potential, coverage, or signal strength.
• Designing a Survey Tool for Monitoring Enterprise QoE Borchert, Kathrin; Hirth, Matthias; Zinner, Thomas; Göritz, Anja in ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) (2017).
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  Enterprise applications like SAP are part of the day-to-day work of a large number of employees. Similar to many modern applications, enterprise applications are often implemented in a distributed fashion and consequently suffer from network degradations resulting in impairments like increased loading delays. While the influence of these impairments on the perceived quality of users is well researched for consumer applications and network services, the impact of these impairments in a business environment is still unclear. To address this gap we develop a non-intrusive software tool for continuously collecting subjective ratings on the performance of an enterprise application from a large crowd of employees. Based on the feedback from a company and results from two initial field studies we discuss the specific challenges when assessing the perceived quality of employees during regular working hours and point our further research directions.

  @inproceedings{info3-inproceedings-2017-13, abstract = {Enterprise applications like SAP are part of the day-to-day work of a large number of employees. Similar to many modern applications, enterprise applications are often implemented in a distributed fashion and consequently suffer from network degradations resulting in impairments like increased loading delays. While the influence of these impairments on the perceived quality of users is well researched for consumer applications and network services, the impact of these impairments in a business environment is still unclear. To address this gap we develop a non-intrusive software tool for continuously collecting subjective ratings on the performance of an enterprise application from a large crowd of employees. Based on the feedback from a company and results from two initial field studies we discuss the specific challenges when assessing the perceived quality of employees during regular working hours and point our further research directions.}, address = {Los Angeles, CA, USA}, author = {Borchert, Kathrin and Hirth, Matthias and Zinner, Thomas and Göritz, Anja}, booktitle = {ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE)}, keywords = {ua-net}, month = 8, title = {Designing a Survey Tool for Monitoring Enterprise QoE}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-13 %A Borchert, Kathrin %A Hirth, Matthias %A Zinner, Thomas %A Göritz, Anja %B ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) %C Los Angeles, CA, USA %D 2017 %T Designing a Survey Tool for Monitoring Enterprise QoE %X Enterprise applications like SAP are part of the day-to-day work of a large number of employees. Similar to many modern applications, enterprise applications are often implemented in a distributed fashion and consequently suffer from network degradations resulting in impairments like increased loading delays. While the influence of these impairments on the perceived quality of users is well researched for consumer applications and network services, the impact of these impairments in a business environment is still unclear. To address this gap we develop a non-intrusive software tool for continuously collecting subjective ratings on the performance of an enterprise application from a large crowd of employees. Based on the feedback from a company and results from two initial field studies we discuss the specific challenges when assessing the perceived quality of employees during regular working hours and point our further research directions.
• An Approximation of the Backhaul Bandwidth Aggregation Potential Using a Partial Sharing Scheme Burger, Valentin; Seufert, Michael; Zinner, Thomas; Tran-Gia, Phuoc in 15th IFIP/IEEE International Symposium on Integrated Network Management (IM) (2017).
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  To cope with the increasing demands of mobile devices and the limited capacity of cellular networks, mobile connections are offloaded to WiFi. The access capacity is further increased by aggregating backhaul bandwidth of WiFi access links. To analyze the performance of aggregated access links we develop a model for two and more cooperating systems sharing capacities using an offloading scheme. The state probabilities of the different cooperating systems in the analytic model are determined by a fixed point iterative procedure. By investigating an inner and outer composite system we are able to analyze the system in imbalanced load conditions where the system reaches its full potential utilizing spare bandwidth. To evaluate the robustness of the system against users that try to exploit the system, the bandwidth received by prioritized users is quantified.

  @inproceedings{info3-inproceedings-2017-1, abstract = {To cope with the increasing demands of mobile devices and the limited capacity of cellular networks, mobile connections are offloaded to WiFi. The access capacity is further increased by aggregating backhaul bandwidth of WiFi access links. To analyze the performance of aggregated access links we develop a model for two and more cooperating systems sharing capacities using an offloading scheme. The state probabilities of the different cooperating systems in the analytic model are determined by a fixed point iterative procedure. By investigating an inner and outer composite system we are able to analyze the system in imbalanced load conditions where the system reaches its full potential utilizing spare bandwidth. To evaluate the robustness of the system against users that try to exploit the system, the bandwidth received by prioritized users is quantified.}, address = {Lisbon, Portugal}, author = {Burger, Valentin and Seufert, Michael and Zinner, Thomas and Tran-Gia, Phuoc}, booktitle = {15th IFIP/IEEE International Symposium on Integrated Network Management (IM)}, keywords = {ngn}, month = 5, title = {An Approximation of the Backhaul Bandwidth Aggregation Potential Using a Partial Sharing Scheme}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-1 %A Burger, Valentin %A Seufert, Michael %A Zinner, Thomas %A Tran-Gia, Phuoc %B 15th IFIP/IEEE International Symposium on Integrated Network Management (IM) %C Lisbon, Portugal %D 2017 %T An Approximation of the Backhaul Bandwidth Aggregation Potential Using a Partial Sharing Scheme %X To cope with the increasing demands of mobile devices and the limited capacity of cellular networks, mobile connections are offloaded to WiFi. The access capacity is further increased by aggregating backhaul bandwidth of WiFi access links. To analyze the performance of aggregated access links we develop a model for two and more cooperating systems sharing capacities using an offloading scheme. T