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  • Moldovan, Christian; Skorin-Kapov, Lea; Heegaard, Poul; Hoßfeld, Tobias: Optimal Fairness and Quality in Video Streaming With Multiple Users. In: Ieee (Hrsg.): 30th International Teletraffic Congress (ITC 30). Vienna, Austria 2018. BIB Download Details
  • Sebastian Surminski, Christian Moldovan; Tobias Hoßfeld: Practical QoE Evaluation of Adaptive Video Streaming. In: Reinhard German, Kai-Steffen Hielscher; Udo R. Krieger (Hrsg.): Measurement, Modelling and Evaluation of Computing Systems. Springer International Publishing, Cham 2018, S. 283-292. Volltext BIB Download Details
  • Seufert, Michael; Moldovan, Christian; Burger, Valentin; Hoßfeld, Tobias: Applicability and Limitations of a Simple WiFi Hotspot Model for Cities. In: 13th International Conference on Network and Service Management (CNSM). Tokyo, Japan 2017. BIB Download Details
  • Sebastian Surminski; Florian Metzger; Tobias Hoßfeld; Poul E. Heegaard: Traffic of the Future: Modeling IoT Traffic Patterns. Poster (Hrsg.), ITG Fachtagung "Zukunft der Netze 2017", Lübeck 2017. BIB Download Details
  • Moldovan, Christian; Hoßfeld, Tobias; Hagn, Korbinian; Sieber, Christian; Kellere, Wolfgang: Keep Calm and Don’t Switch: About the Relationship Between Switches and Quality in HAS. In: 29th International Teletraffic Congress (ITC 29). Genoa, Italy 2017. Volltext BIB Download Details
  • Sebastian Surminski, Christian Moldovan; Tobias Hoßfeld: Saving Bandwidth by Limiting the Buffer Size in HTTP Adaptive Streaming. In: Udo R. Krieger; Thomas C. Schmidt; Andreas Timm-Giel (Hrsg.): MMBnet 2017 - Proceedings of the 9th GI/ITG Workshop „Leistungs-, Verlässlichkeits- und Zuverlässigkeitsbewertung von Kommunikationsnetzen und Verteilten Systemen“. University of Bamberg Press, Hamburg 2017, S. 5-21. doi:10.20378/irbo-49762 Volltext BIB Download Details
  • Egger, Sebastian; Redi, Judith; Hoßfeld, Tobias; Hirth, Matthias; Möller, Sebastian; Naderi, Babak; Keimel, Chistian: Crowdsourcing for QoE Experiments. In: Archambault, Daniel; Hoßfeld, Tobias; Purchase, Helen, C. (Hrsg.): Evaluation in the Crowd: Crowsourcing and Human-Centred Experiments. Springer, ISBN 978-3-319-66435-4, 2017. Volltext BIB Download Details
  • Martin, David; Carpendale, Sheelagh; Gupta, Neha; Hoßfeld, Tobias; Naderi, Babak; Redi, Judith; Siahaan, Ernestasia; Wechsung, Ina: Understanding the Crowd: Ethical and Practical Matters in the Academic Use of Crowdsourcing. In: Archambault, Daniel; Hoßfeld, Tobias; Purchase, Helen, C. (Hrsg.): Evaluation in the Crowd: Crowsourcing and Human-Centred Experiments. Springer, ISBN 978-3-319-66435-4, 2017. Volltext BIB Download Details
  • Antons, Jan-Niklas; Egger, Sebastian; Hoßfeld, Tobias; Möller, Sebastian (Hrsg.): Proceedings of The Fifth Workshop on Perceptual Quality of Systems (PQS 2016). ISCA, TU Berlin, Germany 2017. BIB Download Details
  • Hoßfeld, Tobias; Heegaard, Poul E.; Skorin-Kapov, Lea; Varela, Martin: No Silver Bullet: QoE Metrics, QoE Fairness, and User Diversity in the Context of QoE Management. In: 9th International Conference on Quality of Multimedia Experience. Erfurt, Germany 2017. Volltext BIB Download Details
  • Moldovan, Christian; Metzger, Florian; Surminski, Sebastian; Hoßfeld, Tobias; Burger, Valentin: Viability of Wi-Fi Caches in an Era of HTTPS Prevalence. In: IEEE Communications Society; Institute of Electrical; Electronics Engineers, Institute of Electrical; Electronics Engineers (Hrsg.): IEEE ICC'17: Bridging People, Communities, and Cultures. Paris, France 2017. Volltext BIB Download Details
  • Hossfeld, Tobias; Fiedler, Markus; Gustafsson, Jörgen: Betas: Deriving Quantiles from MOS-QoS Relations of IQX Models for QoE Management. In: QoE-Management Workshop (Hrsg.): IEEE/IFIP IM 2017. Lisbon, Portugal 2017. Volltext BIB Download Details
  • Lareida, Andri; Hoßfeld, Tobias; Stiller, Burkhard: The BitTorrent Peer Collector Problem. In: Ieee (Hrsg.): Integrated Network and Service Management (IM), 2017 IFIP/IEEE. Lisbon, Portugal 2017. doi:10.23919/INM.2017.7987311 Volltext BIB Download Details
  • Tobias Hoßfeld: 2016 International Teletraffic Congress (ITC 28) Report - The First International Conference in Networking Science & Practice. In: SIGCOMM Comput. Commun. Rev. 47, 2 (May 2017), 30-35. Würzburg, Germany 2017. doi:10.1145/3089262.3089268 Volltext BIB Download Details
  • Hossfeld, Tobias; Skorin-Kapov, Lea; Heegaard, Poul E.; Varela, Martín: Definition of QoE Fairness in Shared Systems. In: IEEE Communications Society; Institute of Electrical; Electronics Engineers, Institute of Electrical; Electronics Engineers (Hrsg.): IEEE Communications Letters, Volume: 21. 2016. doi:10.1109/LCOMM.2016.2616342 Volltext BIB Download Details
  • Moldovan, Christian; Metzger, Florian: Bridging the Gap Between QoE and User Engagement in HTTP Video Streaming. In: 28th International Teletraffic Congress (ITC 28). Würzburg, Germany 2016. Volltext BIB Download Details
  • Moldovan, Christian; Sieber, Christian; Heegaard, Poul; Kellerer, Wolfgang; Hoßfeld, Tobias: YouTube Can Do Better: Getting the Most Out of Video Adaptation. In: QCMAN 2016 : Fourth IEEE International Workshop on Quality of Experience Centric Management. Würzburg 2016. Volltext BIB Download Details
  • Moldovan, Christian; Hoßfeld, Tobias: Impact of Variances on the QoE in Video Streaming. In: QCMAN 2016 : Fourth IEEE International Workshop on Quality of Experience Centric Management. Würzburg 2016. Volltext BIB Download Details
  • Hoßfeld, Tobias; Heegaard, Poul E.; Varela, Martín; Möller, Sebastian: QoE Beyond the MOS: An In-Depth Look at QoE via Better Metrics and their Relation to MOS. In: Quality and User Experience (2016). doi:10.1007/s41233-016-0002-1 Volltext BIB Download Details
  • Metzger, Florian; Lioutou, Eirini; Moldovan, Christian; Hoßfeld, Tobias: TCP Video Streaming and Mobile Networks: Not A Love Story, But Better With Context. In: Special Issue of Computer Networks on “Traffic and Performance in the Big Data Era”, Jg. 2016 (2016). Volltext BIB Download Details
  • Seufert, Michael; Hoßfeld, Tobias: One Shot Crowdtesting: Approaching the Extremes of Crowdsourced Subjective Quality Testing. In: PQS 2016. Berlin 2016. Volltext BIB Download Details
  • Hoßfeld, Tobias; Skorin-Kapov, Lea; Heegaard, Poul E.; Varela, Martìn; Chen, Kuan-Ta: On Additive and Multiplicative QoS-QoE Models for Multiple QoS Parameters. In: PQS 2016. Berlin 2016. Volltext BIB Download Details
  • Hirth, Matthias; Allendorf, Fabian; Metzger, Florian; Schwartz, Christian: Assessing the Accuracy of Network Estimations in the DOTA 2 Game Client. In: PQS 2016 5th ISCA/DEGA Workshop on Perceptual Quality of Systems. Berlin 2016. doi:10.21437/PQS.2016-6 Volltext BIB Download Details
  • Metzger, Florian; Rafetseder, Albert; Schwartz, Christian: A Comprehensive End-to-End Lag Model for Online and Cloud Video Gaming. In: PQS 2016 5th ISCA/DEGA Workshop on Perceptual Quality of Systems. Berlin 2016. doi:10.21437/PQS.2016-5 Volltext BIB Download Details
  • Seufert, Michael; Zach, Ondrej; Hoßfeld, Tobias; Slanina, Martin; Tran-Gia, Phuoc: Impact of Test Condition Selection in Adaptive Crowdsourcing Studies on Subjective Quality. In: 8th International Conference on Quality of Multimedia Experience (QoMEX 2016). Lisbon 2016. Volltext BIB Download Details
  • Metzger, Florian; Rafetseder, Albert; Schwartz, Christian; Hoßfeld, Tobias: Games and Frames: A Strange Tale of QoE Studies. In: 8th International Conference on Quality of Multimedia Experience (QoMEX 2016). Lisbon 2016. Volltext BIB Download Details
  • Sackl, Andreas; Schatz, Raimund; Hossfeld, Tobias; Metzger, Florian; Lister, David; Irmer, Ralf: QoE Management Made Uneasy: The Case of Cloud Gaming. In: IEEE ICC 2016. Kuala Lumpur 2016. Volltext BIB Download Details
  • Sieber, Christian; Heegaard, Poul; Hoßfeld, Tobias; Kellerer, Wolfgang; : Sacrificing Efficiency for Quality of Experience: YouTube’s Redundant Traffic Behavior. IFIP Networking 2016, Vienna, Austria 2016. PDF BIB Download Details

    Internet traffic reports show that YouTube is one of the major sources of data traffic world-wide. Furthermore, the data traffic shifts from mostly fixed landlines to cellular data connections where bandwidth is sparse and expensive. Previous studies revealed that YouTube uses a user-friendly HTTP Adaptive Streaming (HAS) strategy which sacrifices bandwidth efficiency to increase the average playback quality for the user. That way, it happens that the same video segment is transmitted in two or more quality levels, but only one can be shown to the user. We denote this as redundant traffic and this work is dedicated to understanding the influence factors on the amount of redundant traffic. This paper presents the results of a large-scale study with over 12,000 video views over a bottleneck link shaped to various bandwidths.We first evaluate the playback characteristics and show that YouTube’s HAS algorithm linearly increases the average playback quality with the available bandwidth while at the same time video buffering is sublinearly decreased. Furthermore, we identify video-dependent bandwidths which optimize the playback time on a quality level. Afterward, we show that this is achieved by discarding lower layer segments and therefore paid with redundant traffic of up to 40%. We evaluate the overall efficiency of the system and show that YouTube is able to improve the average quality level by up to 0.7 quality levels by using this adaptation strategy. However, a penalty of 0.5 quality levels is paid for it due to the discarded data of the lower quality segments.

  • Wamser, Florian; Casas, Pedro; Seufert, Michael; Moldovan, Christian; Tran-Gia, Phuoc; Hoßfeld, Tobias: Modeling the YouTube Stack: from Packets to Quality of Experience. In: Computer Networks (2016). doi:10.1016/j.comnet.2016.03.020 Volltext BIB Download Details
    YouTube is one of the most popular and volume-dominant services in today’s Internet, and has changed the Web for ever. Consequently, network operators are forced to consider it in the design, deployment, and optimization of their networks. Taming YouTube requires a good understanding of the complete YouTube stack, from the network streaming service to the application itself. Understanding the interplays between individual YouTube functionalities and their implications for traffic and user Quality of Experience (QoE) becomes paramount nowadays. In this paper we characterize and model the YouTube stack at different layers, going from the generated network traffic to the QoE perceived by the users watching YouTube videos. Firstly, we present a network traffic model for the YouTube flow control mechanism, which permits to understand how YouTube provisions video traffic flows to users. Secondly, we investigate how traffic is consumed at the client side, deriving a simple model for the YouTube application. Thirdly, we analyze the implications for the end user, and present a model for the quality as perceived by them. This model is finally integrated into a system for real time QoE-based YouTube monitoring, highly useful to operators to assess the performance of their networks for provisioning YouTube videos. The central parameter for all the presented models is the buffer level at the YouTube application layer. This paper provides an extensive compendium of objective tools and models for network operators to better understand the YouTube traffic in their networks, to predict the playback behavior of the video player, and to assess how well they are doing in practice in delivering YouTube videos to their customers.
  • Archambault, Daniel; Hoßfeld, Tobias; Purchase, Helen C.: Crowdsourcing and Human-Centred Experiments (Dagstuhl Seminar 15481). Daniel Archambault; Tobias Hoßfeld; Helen C. Purchase (Hrsg.), Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik, Dagstuhl, Germany 2016. doi:10.4230/DagRep.5.11.103 Volltext BIB Download Details

    This report documents the program and the outcomes of Dagstuhl Seminar 15481 "Evaluation in the Crowd: Crowdsourcing and Human-Centred Experiments". Human-centred empirical evaluations play important roles in the fields of human-computer interaction, visualization, graphics, multimedia, and psychology. The advent of crowdsourcing platforms, such as Amazon Mechanical Turk or Microworkers, has provided a revolutionary methodology to conduct human-centred experiments. Through such platforms, experiments can now collect data from hundreds, even thousands, of participants from a diverse user community over a matter of weeks, greatly increasing the ease with which we can collect data as well as the power and generalizability of experimental results. However, such an experimental platform does not come without its problems: ensuring participant investment in the task, defining experimental controls, and understanding the ethics behind deploying such experiments en-masse. The major interests of the seminar participants were focused in different working groups on (W1) Crowdsourcing Technology, (W2) Crowdsourcing Community, (W3) Crowdsourcing vs. Lab, (W4) Crowdsourcing & Visualization, (W5) Crowdsourcing & Psychology, (W6) Crowdsourcing & QoE Assessment.

  • Liotou, Eirini; Hoßfeld, Tobias; Moldovan, Christian; Metzger, Florian; Tsolkas, Dimitris; Passas, Nikos: Enriching HTTP Adaptive Streaming with Context Awareness - A Tunnel Case Study. In: CQRM - Communications QoS, Reliability and Modeling Symposium. ICC, 2016. Volltext BIB Download Details
  • Seufert, Michael; Griepentrog, Tobias; Burger, Valentin; Hoßfeld, Tobias: A Simple WiFi Hotspot Model for Cities. In: IEEE Communications Letters, Jg. 2016 (2016) Nr. 20, S. 384-387. doi:10.1109/LCOMM.2015.2509074 Volltext BIB Download Details
  • Burger, Valentin; Seufert, Michael; Hoßfeld, Tobias, Tran-Gia, Phuoc: Performance evaluation of backhaul bandwidth aggregation using a partial sharing scheme. In: Physical Communication (2016). doi:10.1016/j.phycom.2016.01.005 Volltext BIB Download Details

    To cope with the increasing demand of mobile devices and the limited capacity of cellular networks mobile connections are offloaded to WiFi. The access capacity is further increased, by aggregating bandwidth of WiFi access links. To analyze the performance of aggregated access links we model the most simple case of two cooperating systems interchanging capacities using an offloading scheme. The resulting analytic model is computed by means of a two-dimensional birth and death process. It can be used to seamlessly evaluate the performance of systems between partitioning and complete sharing. This allows to optimize the setting of thresholds dependent on the load of the cooperating system. Furthermore the benefit of aggregating bandwidth in different scenarios with homogeneous and heterogeneous workloads is quantified and the performance of more than two cooperating systems is evaluated by simulation.

  • Hirth, Matthias; Hoßfeld, Tobias; Mellia, Marco; Schwartz, Christian; Lehrieder, Frank: Crowdsourced network measurements: Benefits and best practices. In: Elsevier Computer Networks, Jg. 2015 (2015) Nr. 90, S. 85-98. doi:Crowdsourced network measurements: Benefits and best practices Volltext BIB Download Details
  • Seufert, Michael; Hoßfeld, Tobias; Sieber, Christian: Impact of Intermediate Layer on Quality of Experience of HTTP Adaptive Streaming.. In: 11th International Conference on Network and Service Management (CNSM). IEEE, Barcelona, Spain 2015. doi:10.1109/CNSM.2015.7367367 Volltext BIB Download Details
  • Computer Networks: The International Journal of Computer; Telecommunications Networking (Hrsg.): Special issue on crowdsourcing. Elsevier, 2015. doi:10.1016/j.comnet.2015.05.015 Volltext BIB Download Details

    Over the past several years crowdsourcing has not only emerged as a new research theme, but also as a new Web-enabled service platform for harnessing the skills of the network-connected crowd. In contrast to outsourcing, where a designated worker or an employee performs a job, crowdsourcing means outsourcing a job to a large, anonymous crowd of workers, the so-called human cloud, most commonly in the form of an open call.

    Whilst the research community has not yet recognized crowdsourcing as an entirely new discipline, it poses many research challenges. Crowdsourcing research intersects many existing domains and brings to the surface new challenges, such as crowdtesting as a novel methodology for user-centered research; development of new services and applications based on human sensing, computation and problem solving; engineering improved crowdsourcing platforms including quality control mechanisms; incentive design and gamification of work; and usage of crowdsourcing for professional business. Crowdsourcing, as a new means of engaging human capital online is increasingly having an impact on the Internet and its technical infrastructure, on society, and the future of work. Although crowdsourcing is an increasingly relevant topic, there are few researchers looking at networking aspects of this phenomenon.

    This special issue is devoted to the most recent developments and research outcomes focusing on the research topics above. Thereby, two different research communities were addressed: crowdsourcing experts and networking experts. Accordingly papers from both communities are included in this special issue. This makes the special issue different than typical computer networks special issues with a clear focus on computer and communication networks. In this special issue, on one hand, crowdsourcing experts are discussing challenges and opportunities of crowdsourcing and hybrid human-machine information systems in general. A particular focus is on incentives and motivation of the crowd as a key challenge for the success of crowdsourcing. Novel and promising applications and use cases of crowdsourcing are highlighted and discussed. On the other hand, the networking facets of crowdsourcing are considered which are strongly related to particular use cases like mobile sensing or WiFi community sharing. But crowdsourcing is also utilized as a means for network measurements and quality testing.

    It should be noted that due to the novelty of the crowdsourcing topic in computer networks and the integration of both research communities, the articles take a slightly different form than typical computer network articles. Experience reports and studies of crowdsourcing providing best practices and lessons learned were encouraged for the special issue. Furthermore, the interdisciplinary research theme also touches areas beyond networking like incentives, motivation or skill testing of the crowd.

    In total, 11 articles were accepted which are grouped in five different areas: (A) overview on challenges and opportunities, (B) incentives and motivation, (C) mobile crowdsourcing, (D) crowdtesting, (E) further use cases for crowdsourcing.

    An overview on crowdsourcing is provided in “Hybrid Human–Machine Information Systems: Challenges and Opportunities” by Gianluca Demartini. The focus is on micro-tasks in crowdsourcing as the core component of data-driven systems. Micro-tasks are fine-granular, short and typically simple to fulfill. The integration of micro-task crowdsourcing in data-driven machine-based systems leads to hybrid human-machine systems with promising advantages and new opportunities for service creation and data analysis. The article sketches crucial challenges for the design of such systems and overviews existing hybrid human-machine systems. Open research directions are derived which need to be addressed for future data processing with humans in the loop and machine clouds.

    A major issue beside the quality of the results generated by the crowd are incentives and motivation of the crowd. In crowdsourcing, the individual user decides which tasks to conduct and therefore successful crowdsourcing depends on the ability to incentivize users to participate. Motivation can be extrinsic or intrinsic. A variety of different reasons may be relevant for the individual human like financial incentives and extrinsic motivation as in commercial crowdsourcing platforms. But users may also have intrinsic motivation to participate in crowdsourcing like social responsibility, e.g., Wikipedia as an example, to gather and maintain knowledge, or a desire for entertainment. Ognjen Scekic, Hong-Linh Truong, and Schahram Dustdar propose a domain-specific language for incentive management in their article: “PRINGL: A Domain-Specific Language for Incentive Management in Crowdsourcing”. The proposed PRINGL language for programming and managing complex incentive strategies for crowdsourcing platforms which are also addressing more intellectually-challenging tasks and intrinsic motivation. PRINGL promotes re-use of proven incentive logic and simplifies modeling, adjustment and enactment of complex incentives for socio-technical systems. Its applicability and expressiveness on a set of realistic use-cases is presented in the article. Jorge Goncalves et al. consider motivation and incentives for the special case of ubiquitous crowdsourcing which is gaining increased interest due to mobile and ubiquitous technology like smartphones but also public displays. In their article “Motivating Participation and Improving Quality of Contribution in Ubiquitous Crowdsourcing”, the effect of motivation on participation, performance and result quality is investigated. The results are obtained from field studies and the results show the need for proper incentive management. The experience and the conclusions from these studies yield recommendations on the design and implementation of ubiquitous crowdsourcing.

    The next part in the special issue addresses explicitly mobile crowdsourcing and mobile participatory sensing applications. With participatory sensing, the crowd is utilized to collect data, e.g., with sensors available on smartphone devices, for monitoring and analysis of environmental phenomena. With crowdsourcing, access to a large pool of humans and their sensing devices is granted. Nevertheless, data quality must be ensured. Hayam Mousa et al. survey trust and reputation systems proposed in the literature to trace participants' behaviors in mobile participatory sensing applications. The article “Trust Management and Reputation Systems in Mobile Participatory Sensing Applications: A Survey” presents a study and analysis of existing trust systems in participatory sensing applications. A focus is on their main vulnerabilities and possible attacks. A classification of existing trust systems is provided which shows that many trust problems have not been solved and many attacks have not been addressed yet in the literature. This leaves room for future research directions regarding trust management in participatory sensing systems. Tomoyo Sasao et al. focus on mobile crowdsourcing for citizens to solve local issues in context. In the article “Context Weaver: Awareness and Feedback in Networked Mobile Crowdsourcing Tools”, a system called Context Weaver is proposed. Participants in the mobile crowdsensing system are connected in order to support collaborative exploration. In field trials, experience is gained to understand the effect of networking participants on crowdsourced data-collection activities. A methodology for exploratory mobile crowdsourcing by citizens is discussed which is based on the provision of mutual awareness and rapid feedback in context.

    Another successful use case of crowdsourcing is crowdtesting. Crowdtesting utilizes the human crowd for conducting scientific studies, e.g., in the context of user perceived quality, or product and software evaluation. To this end, crowdsourcing can also be utilized for conducting network measurements. Matthias Hirth et al. revisit network measurements approaches and the importance of network measurements for both the operation of networks and for the design and evaluation of new mechanisms. To complement the existing techniques, they consider the usage of crowdsourcing platforms for network measurements in the article “Crowdsourced Network Measurements: Benefits and Best Practices”. Crowdsourcing is compared with traditional network measurement techniques and possible pitfalls and limitations are discussed. Best practices are provided as to how to use crowdsourcing in the area of network measurements as well as a guideline for researchers when and how to exploit crowdsourcing for network measurements. Thomas Volk et al. utilize the crowd for testing the system on the user level. Experiments for the subjective evaluation of multimedia presentations and content are moved from traditional laboratory environments to the crowd. The article “Crowdsourcing vs. Laboratory Experiments - QoE Evaluation of Binaural Playback in a Teleconference Scenario” considers a teleconference system. In the crowdsourcing setting, a real-life environment is tested which is compared to the results from a laboratory controlled environment. As a result, intriguing differences between the results of laboratory and crowdsourcing experiments were observed in terms of reliability, availability and efficiency. Maria Christoforaki and Panagiotis G. Ipeirotis consider the problem of reliably evaluating the skills of the participating users. They present a platform in their article “A System for Scalable and Reliable Technical-Skill Testing in Online Labor Markets” which allows continuous generation of test questions and predicting the user skill level. Those questions are created close to the real world problems to be solved by the crowd and the technique is based on item response theory. But also external signals are used to examine the external validity of the generated test questions. This is a promising approach to identify workers that have the skills to successfully execute a task. The platform is evaluated with experiments.

    The final part of the special issue addresses use cases beside mobile crowdsourcing and crowdtesting. Those use cases demonstrate the potential of crowdsourcing for applications in enterprise, arts, but also for wireless access through WiFi community sharing. Mahmood Hosseini et al. focus on the usage of crowdsourcing in enterprises based on the assumption of the wisdom of the crowd. Decisions collectively made by a diverse crowd could be better than those made by an elite group of experts if preconditions are fulfilled. Their article “Wisdom of Crowd in UK Enterprises” reflects how the wisdom of the crowd worked in the practice of modern enterprises. An empirical study in the UK from 33 different industries discusses and analyses the current practices. Those insights may be fruitful for the analysis and design of crowdsourcing based solutions in enterprises. Jasper Oosterman et al. are looking at visual artwork annotations in cultural heritage. Corresponding institutes collect annotations of the represented object to enable human access and retrieval in online systems. Crowdsourcing may be used to collect the annotated data which differs from simple data annotation, as the crowd requires special knowledge and skills. In their article “Crowdsourcing Visual Artwork Annotations in Cultural Heritage”, a real-life case study from the Rijksmuseum in Amsterdam is considered and crowd annotations are compared to trusted annotators. The results show that well-known results from photographic image annotation cannot be straightforwardly applied to artwork annotation. Roger Baig et al. use crowdsourcing in a different way in order to provide a common network infrastructure. Crowdsourced computer networks refer to network infrastructure built by citizens and organizations who pool their resources and coordinate their efforts to realize such networks. The article “Crowdsourcing tools for designing, deploying and operating network infrastructure held in commons” discusses the case of guifi.net and presents its principles and the current implementation. Lessons learned from the use case are shared paying attention to the role of crowdsourcing processes and tools.

    The guest editors would like to thank the authors and also the reviewers for their great work. The special issue is the outcome of the the Dagstuhl Seminar 13361: “Crowdsourcing: From Theory to Practice and Long-Term Perspectives” which was organized by the special issue editors. Participants from the Dagstuhl seminar were actively involved as reviewers and authors of the papers. The work devoted to the special issue is partly supported by the Deutsche Forschungsgemeinschaft (DFG) under Grants HO4770/2-1 and TR257/38-1 related to the project “Design and evaluation of new mechanisms for crowdsourcing as emerging paradigm for the organization of work in the Internet”.

  • Jarschel, Michael; Hoßfeld, Tobias; Davoli, Franco; Bolla, Raffaele; Bruschi, Roberto; Carrega, Alessandro: SDN-Enabled Energy-Efficient Network Management. In: Konstantinos Samdanis; Peter Rost; Andreas Maeder; Michela Meo; Christos Verikoukis (Hrsg.): Green Communications: Principles, Concepts and Practice. 1. Auflage. John Wiley & Sons, 2015, S. 323-338. Volltext BIB Download Details
  • Hoßfeld, Tobias; Metzger, Florian; Jarschel, Michael: QoE in Cloud Gaming. In: IEEE COMSOC MMTC E-Letter, Jg. 2015 (2015) Nr. 10-6, S. 26-29. Volltext BIB Download Details
  • Gardlo, Bruno; Egger, Sebastian; Hossfeld, Tobias: Do Scale-Design and Training Matter for Video QoE Assessments through Crowdsourcing?. In: Fourth International ACM Workshop on Crowdsourcing for Multimedia. Brisbane, Australia 2015. PDF BIB Download Details
  • Redi, Judith; Siahaan, Ernestasia; Korshunov, Pavel; Habigt, Julian; Hossfeld, Tobias: When the crowd challenges the lab: lessons learnt from subjective studies on image aesthetic appeal. In: Fourth International ACM Workshop on Crowdsourcing for Multimedia. Brisbane, Australia 2015. PDF BIB Download Details
  • Seufert, Michael; Schwind, Anika; Hoßfeld, Tobias; Tran-Gia, Phuoc: Analysis of Group-based Communication in WhatsApp. In: 7th EAI International Conference on Mobile Networks and Management. Santander, Spain 2015. Volltext BIB Download Details
  • Seufert, Michael; Lange, Stanislav; Hoßfeld, Tobias: More than topology: Joint topology and attribute sampling and generation of social network graphs. In: Elsevier Computer Communications, Jg. 2016 (2015) Nr. 73,B, S. 176-187. doi:10.1016/j.comcom.2015.07.023 Volltext BIB Download Details
  • Seufert, Michael; Burger, Valentin; Wamser, Florian; Tran-Gia, Phuoc; Moldovan, Christian; Hoßfeld, Tobias: Utilizing Home Router Caches to Augment CDNs toward Information-Centric Networking. In: EuCNC 2015. Paris, France 2015. Volltext BIB Download Details
  • Hoßfeld, Tobias; Heegard, Poul; Varela, Martin: QoE beyond the MOS: Added Value Using Quantiles and Distributions. QoMEX 2015, Costa Navarino, Greece 2015. Volltext BIB Download Details
  • Varela, Martín; Skorin-Kapov, Lea; Mäki, Toni; Hoßfeld, Tobias: QoE in the Web: A Dance of Design and Performance. QoMEX 2015, Costa Navarino, Greece 2015. Volltext BIB Download Details
  • Hoßfeld, Tobias; Redi, Judith: Journey through the crowd: Best Practices and Recommendations for Crowdsourced QoE. In: QoMEX 2015. Costa Navarino, Greece 2015. Volltext BIB Download Details
  • Hoßfeld, Tobias; Fiedler, Markus: The Unexpected QoE Killer: When the Network Emulator Misshapes Traffic and QoE. In: QoMEX 2015. Costa Navarino, Greece 2015. Volltext BIB Download Details
  • Reichl, Peter; Egger, Sebastian; Möller, Sebastian; Kilkki, Kalevi; Fiedler, Markus; Hossfeld, Tobias; Tsiaras, Christos; Asrese, Alemnew: Towards a comprehensive framework for QoE and user behavior modelling. In: QoMEX 2015. Costa Navarino, Greece 2015. Volltext BIB Download Details
  • Hossfeld, Tobias; Skorin-Kapov, Lea; Haddad, Yoram; Pocta, Peter; Siris, Vasilios A.; Zgank, Andrej; Melvin, Hugh; : Can context monitoring improve QoE? A case study of video flash crowds in the Internet of Services. In: QCMAN 2015 - Third IFIP/IEEE International Workshop on Quality of Experience Centric Management. Ottawa, Canada 2015. Volltext BIB Download Details
  • Tobias Hoßfeld; Michael Seufert; Christian Sieber; Thomas Zinner; Phuoc Tran-Gia: Identifying QoE Optimal Adaptation of HTTP Adaptive Streaming Based on Subjective Studies. In: Elsevier Computer Networks, Jg. 2015 (2015) Nr. 81, S. 320-332. doi:10.1016/j.comnet.2015.02.015 Volltext BIB Download Details

    HTTP Adaptive Streaming (HAS) technologies, e.g., Apple HLS or MPEG-DASH, automatically adapt the delivered video quality to the available network. This reduces stalling of the video but additionally introduces quality switches, which also influence the user-perceived Quality of Experience (QoE). In this work, we conduct a subjective study to identify the impact of adaptation parameters on QoE. The results indicate that the video quality has to be maximized first, and that the number of quality switches is less important. Based on these results, a method to compute the optimal QoE-optimal adaptation strategy for HAS on a per user basis with mixed-integer linear programming is presented. This QoE-optimal adaptation enables the benchmarking of existing adaptation algorithms for any given network condition. Moreover, the investigated concept is extended to a multi-user IPTV scenario. The question is answered whether video quality, and thereby, the QoE can be shared in a fair manner among the involved users.

  • Tobias Hoßfeld; Christian Moldovan; Christian Schwartz: To Each According to his Needs: Dimensioning Video Buffer for Specific User Profiles and Behavior. In: QCMAN 2015. Ottawa, Canada 2015. PDF BIB Download Details
  • Hoßfeld, T.; Hirth, M.; Redi, J.; Mazza, F.; Korshunov, P.; Naderi, B.; Seufert, M.; Gardlo, B.; Egger, S.; Keimel, C.: Best Practices and Recommendations for Crowdsourced QoE - Lessons learned from the Qualinet Task Force Crowdsourcing. European Network on Quality of Experience in Multimedia Systems; Services (COST Action IC 1003 Qualinet) (Hrsg.), 2014. PDF Volltext BIB Download Details
  • Seufert, M.; Egger, S.; Slanina, M.; Zinner, T.; Hossfeld, T.; Tran-Gia, P.: A Survey on Quality of Experience of HTTP Adaptive Streaming. In: IEEE Communications Surveys & Tutorials, Jg. 2014 (2014). doi:10.1109/COMST.2014.2360940 Volltext BIB Download Details
  • Tobias Hoßfeld; Michael Seufert; Christian Sieber; Thomas Zinner; Phuoc Tran-Gia: Close to Optimum? User-centric Evaluation of Adaptation Logics for HTTP Adaptive Streaming. In: PIK - Praxis der Informationsverarbeitung und Kommunikation, Jg. 2014 (2014). doi: 10.1515/pik-2014-0029 Volltext BIB Download Details
  • Hoßfeld, T.; Keimel, C.; Timmerer, C.: Crowdsourcing Quality-of-Experience Assessments. In: IEEE Computer, Jg. 2014 (2014) Nr. 47, S. 98-102. doi:10.1109/MC.2014.245 Volltext BIB Download Details
  • Seufert, Michael; Darzanos, George; Papafili, Ioanna; Lapacz, Roman; Burger, Valentin; Hoßfeld, Tobias: Socially-Aware Traffic Management. In: Zweig, Katharina, Neuser, Wolfgang; Pipek, Volkmar; Rohde, Markus; Scholtes, Ingo (Hrsg.): Socioinformatics - The Social Impact of Interactions between Humans and IT. Springer International Publishing, 2014, S. 25-43. Volltext BIB Download Details
  • Burger, Valentin; Hock, Davi; Scholtes, Ingo; Hoßfeld, Tobias; Garcia, David; Seufert, Michael: Social Network Analysis in the Enterprise: Challenges and Opportunities. In: Zweig, Katharina, Neuser, Wolfgang; Pipek, Volkmar; Rohde, Markus; Scholtes, Ingo (Hrsg.): Socioinformatics - The Social Impact of Interactions between Humans and IT. Springer International Publishing, 2014, S. 95-120. Volltext BIB Download Details
  • Hoßfeld, Tobias; Burger, Valentin; Hinrichsen, Haye; Hirth, Matthias; Tran-Gia, Phuoc: On the computation of entropy production in stationary social networks. In: Social Network Analysis and Mining, Jg. 4 (2014). Volltext BIB Download Details
  • Hoßfeld, Tobias: On Training the Crowd for Subjective Quality Studies. In: VQEG eLetter, Jg. 1 (2014). Volltext BIB Download Details
  • Hirth, Matthias; Scheuring, Sven; Hoßfeld, Tobias; Schwartz, Christian; Tran-Gia, Phuoc: Predicting Result Quality in Crowdsourcing Using Application Layer Monitoring. In: 5th International Conference on Communications and Electronics (ICCE 2014). Da Nang, Vietnam 2014. Volltext BIB Download Details
  • Burger, Valentin; Hirth, Matthias; Schwartz, Christian; Hoßfeld, Tobias: Increasing the Coverage of Vantage Points in Distributed Active Network Measurements by Crowdsourcing. In: Measurement, Modelling and Evaluation of Computing Systems (MMB 2014). Bamberg, Germany 2014. Volltext BIB Download Details
  • Hoßfeld, Tobias; Hirth, Matthias; Korshunov, Pavel; Hanhart, Philippe; Gardlo, Bruno; Keimel, Christian; Timmerer, Christian: Survey of Web-based Crowdsourcing Frameworks for Subjective Quality Assessment. In: 16th International Workshop on Multimedia Signal Processing. Jakarta, Indonesia 2014. Volltext BIB Download Details
  • Hoßfeld, Tobias; Keimel, Christian: Crowdsourcing in QoE Evaluation. In: Sebastian Möller, Alexander Raake (Hrsg) (Hrsg.): Quality of Experience: Advanced Concepts, Applications and Methods. Springer: T-Labs Series in Telecommunication Services, ISBN 978-3-319-02680-0, 2014. Volltext BIB Download Details
  • Hossfeld, Tobias; Keimel, Christian; Hirth, Matthias; Gardlo, Bruno; Habigt, Julian; Diepold, Klaus; Tran-Gia, Phuoc: Best Practices for QoE Crowdtesting: QoE Assessment with Crowdsourcing. In: Transactions on Multimedia, Jg. 16 (2014). Volltext BIB Download Details
  • Hoßfeld, Tobias; Schatz, Raimund; Krieger, Udo: QoE of YouTube Video Streaming for Current Internet Transport Protocols. In: Measurement, Modelling and Evaluation of Computing Systems (MMB 2014). Bamberg, Germany 2014. Volltext BIB Download Details
  • Hoßfeld, Tobias; Seufert, Michael; Sieber, Christian; Zinner, Thomas: Assessing Effect Sizes of Influence Factors Towards a QoE Model for HTTP Adaptive Streaming. In: 6th International Workshop on Quality of Multimedia Experience (QoMEX). Singapore 2014. Volltext BIB Download Details
  • Hoßfeld, Tobias; Timmerer, Christian: Quality of Experience Assessment using Crowdsourcing. In: IEEE COMSOC MMTC R-Letter, Jg. 5 (2014). Volltext BIB Download Details
  • Jarschel, Michael; Zinner, Thomas; Hoßfeld, Tobias; Tran-Gia, Phuoc; Kellerer; Wolfgang: Interfaces, Attributes, and Use Cases: A Compass for SDN. In: IEEE Communications Magazine, Jg. 52 (2014). Volltext BIB Download Details
  • Metzger, Florian; Schwartz, Christian; Hoßfeld, Tobias: GTP-based Load Model and Virtualization Gain for a Mobile Network’s GGSN. In: 5th International Conference on Communications and Electronics. Da Nang, Vietnam 2014. Volltext BIB Download Details
  • Oechsner, Simon; Bellalta, Boris; Dimitrova, Desislava; Hoßfeld, Tobias: Visions and Challenges for Sensor Network Collaboration in the Cloud. In: The Eighth International Conference on Innovative Mobile and Internet Services in Ubiquitous Computing (IMIS-2014). Birmingham, UK 2014. BIB Download Details
  • Schwartz, Christian; Hirth, Matthias; Hoßfeld, Tobias; Tran-Gia, Phuoc: Performance Model for Waiting Times in Cloud File Synchronization Services. In: 26th International Teletraffic Congress (ITC). Karlskrona, Sweden 2014. Volltext BIB Download Details
  • Wajda, Krzysztof; Stankiewicz, Rafal; Dulinski, Zbigniew; Hoßfeld, Tobias; Seufert, Michael; Hausheer, David; Wichtlhuber, Matthias; Papafili, Ioanna; Dramitinos, Manos; Cruschelli, Paolo; Soursos, Sergios; Lapacz, Roman; Stiller, Burkhard: Socially-aware Management of New Overlay Applications Traffic - The Optimization Potentials of the SmartenIT Approach. In: 6th International Conference on Mobile Networks and Management (MONAMI). Würzburg, Germany 2014. Volltext BIB Download Details
  • Strohmeier, Dominik; Egger, Sebastian; Raake, Alexander; Schatz, Raimund; Hoßfeld, Tobias: Web Browsing. In: Sebastian Möller, Alexander Raake (Hrsg) (Hrsg.): Quality of Experience: Advanced Concepts, Applications and Methods. Springer: T-Labs Series in Telecommunication Services, ISBN 978-3-319-02680-0, 2014. Volltext BIB Download Details
  • Zinner, Thomas; Hoßfeld, Tobias; Fiedler, Markus; Liers, Florian; Volkert, Thomas; Khondoker, Rahamatullah; Schatz, Raimund: Requirement Driven Prospects for Realizing User-Centric Network Orchestration. In: Multimedia Tools and Applications, doi: 10.1007/s11042-014-2072-5 (2014). Volltext BIB Download Details
  • Hoßfeld, Tobias; Tran-Gia, Phuoc (Hrsg.): Modelling of Emerging Internet Services: Social Networks and Crowdsourcing - International Journal of Communication Networks and Distributed Systems, Vol. 11, No. 1, 2013. Inderscience Enterprises Ltd. , 2013. Volltext BIB Download Details
  • Amrehn, Philipp; Vandenbroucke, Karel; Hoßfeld, Tobias; Moor, Katrien de; Hirth, Matthias; Schatz, Raimund; Casas, Pedro: Need for Speed? On Quality of Experience for File Storage Services. In: 4th International Workshop on Perceptual Quality of Systems (PQS 2013). Vienna, Austria 2013. Volltext BIB Download Details
  • Casas, Pedro; Schatz, Raimund; Hoßfeld, Tobias: Monitoring YouTube QoE: Is Your Mobile Network Delivering the Right Experience to your Customers?. In: IEEE Wireless Communications and Networking Conference (WCNC 2013). Shanghai, China 2013. Volltext BIB Download Details
  • Burger, Valentin; Hoßfeld, Tobias; Garcia, David; Seufert, Michael; Scholtes, Ingo; Hock, David: Resilience in Enterprise Social Networks. In: Workshop Sozioinformatik 2013. Koblenz, Germany 2013. Volltext BIB Download Details
  • Hausheer, David; Hoßfeld, Tobias (Hrsg) (Hrsg.): Proceedings of the Social-aware Economic Traffic Management for Overlay and Cloud Applications Workshop (SETM 2013). CNSM Workshop 2013, Zürich, Switzerland 2013. Volltext BIB Download Details
  • Redi, Judith; Hossfeld, Tobias; Korshunov, Pavel; Mazza, Filippo; Povoa, Isabel; Keimel, Christian: Crowdsourcing-based multimedia subjective evaluations: a case study on image recognizability and aesthetic appeal. In: ACM CrowdMM 2013. Barcelona, Spain 2013. Volltext BIB Download Details
  • Hoßfeld, Tobias; Tran-Gia, Phuoc; Vukovic, Maja (Hrsg.): Crowdsourcing: From Theory to Practice and Long-Term Perspectives - Report of the Dagstuhl Seminar 13361. Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik, Dagstuhl, Germany 2013. doi:10.4230/DagRep.3.9.1 Volltext BIB Download Details

    This report documents the program and the outcomes of Dagstuhl Seminar 13361 "Crowdsourcing: From Theory to Practice and Long-Term Perspectives". Crowdsourcing is a newly emerging service platform and business model in the Internet. In contrast to outsourcing, where a job is performed by a designated worker or employee, crowdsourcing means to outsource a job to a large, anonymous crowd of workers, the so-called human cloud, in the form of an open call. Current research in crowdsourcing addresses the following issues: crowdsourcing as a novel methodology for user-centered research; development of new services and applications based on human sensing, computation, and problem solving; engineering of improved crowdsourcing platforms including quality control mechanisms; incentive design and gamification of work; usage of crowdsourcing for professional business; theoretical frameworks for evaluation. The topic on crowdsourcing may have a huge impact on the Internet and its technical infrastructure, on society, and the future of work. In short, crowdsourcing will be a guiding paradigm and form the evolution of work in the next years. Therefore, this seminar helps coordinating research efforts in the different communities. In five presentation and discussion sessions, the diverse aspects of crowdsourcing were elaborated. The topics of the sessions covered (S1) crowdsourcing in general, (S2) industry use cases, (S3) crowdsourcing design and engineering, (S4) programming and implementing crowdsourcing, (S5) applications of crowdsourcing. The major interests of the seminar participants were then focused in four different working groups on (W1) long-term perspectives & impact on economics in five years, (W2) theory -- taxonomy and dimensions of crowdsourcing, (W3) industry use cases, (W4) crowdsourcing mechanisms and design. In parallel to this seminar, a topically related seminar on "Cloud-based Software Crowdsouring", organized by Michael N. Huhns, Wei Li, Martin Schader and Wei-Tek Tsal,(Dagstuhl Seminar 13362) took place. Therefore, a joint late night session was organized to discuss crowdsourcing with respect to ethics and its relation to social computation.

  • Hoßfeld, Tobias; Strohmeier, Dominik; Raake, Alexander; Schatz, Raimund: Pippi Longstocking Calculus for Temporal Stimuli Pattern on YouTube QoE. In: 5th ACM Workshop on Mobile Video (MoVid 2013). Oslo, Norway 2013. Volltext BIB Download Details
  • Hoßfeld, Tobias; Schatz, Raimund; Biersack, Ernst; Plissonneau, Louis: Internet Video Delivery in YouTube: From Traffic Measurements to Quality of Experience. In: Biersack, Ernst; Callegari, Christian; Matijasevic, Maja (Hrsg) (Hrsg.): Data Traffic Monitoring and Analysis: From measurement, classification and anomaly detection to Quality of experience. Springer, 2013. Volltext BIB Download Details
  • Hoßfeld, Tobias; Hirth, Matthias; Tran-Gia, Phuoc: Crowdsourcing - Modell einer neuen Arbeitswelt im Internet. In: Informatik Spektrum, Wirtschaftsinformatik & Management, Jg. 5 (2013). Volltext BIB Download Details
  • Hofeld, Tobias; Tran-Gia, Phuoc: Int. J. of Communication Networks and Distributed Systems. BIB Download Details
  • Hinrichsen, Haye; Hoßfeld, Tobias; Hirth, Matthias; Tran-Gia, Phuoc: Entropy Production in Stationary Social Networks. In: 4th Workshop on Complex Networks (CompleNet 2013). Berlin, Germany 2013. Volltext BIB Download Details
  • Schatz, Raimund; Hoßfeld, Tobias (Hrsg) (Hrsg.): Proceedings of The Fourth Workshop on Perceptual Quality of Systems (PQS 2013). FTW, Vienna, Austria 2013. BIB Download Details
  • Sackl, Andreas; Seufert, Michael; Hoßfeld, Tobias: Asking Costs Little? The Impact of Tasks in Video QoE Studies on User Behavior and User Ratings. In: 4th International Workshop on Perceptual Quality of Systems (PQS 2013). Vienna, Austria 2013. Volltext BIB Download Details
  • Schatz, Raimund; Hoßfeld, Tobias; Janowski, Lucjan; Egger, Sebastian: From Packets to People: Quality of Experience as New Measurement Challenge. In: Biersack, Ernst; Callegari, Christian; Matijasevic, Maja (Hrsg) (Hrsg.): Data Traffic Monitoring and Analysis: From measurement, classification and anomaly detection to Quality of experience. Springer, 2013. Volltext BIB Download Details
  • Seufert, Michael; Lorey, Karl; Hirth, Matthias; Hoßfeld, Tobias: Gamification Framework for Personalized Surveys on Relationships in Online Social Networks. In: 1st International Workshop on Crowdsourcing and Gamification in the Cloud (CGCloud). Dresden, Germany 2013. Volltext BIB Download Details
  • Seufert, Michael; Darzanos, George; Burger, Valentin; Papafili, Ioanna; Hoßfeld, Tobias: Socially-Aware Traffic Management. In: Workshop Sozioinformatik 2013. Koblenz, Germany 2013. Volltext BIB Download Details
  • Seufert, Michael; Burger, Valentin; Hoßfeld, Tobias: HORST - Home Router Sharing based on Trust. In: Workshop on Social-aware Economic Traffic Management for Overlay and Cloud Applications (SETM 2013). Zurich, Switzerland 2013. Volltext BIB Download Details
  • Schwartz, Christian; Scheib, Marc; Hoßfeld, Tobias; Tran-Gia, Phuoc; Gimenez-Guzman, Jose Manuel: Trade-Offs for Video-Providers in LTE Networks: Smartphone Energy Consumption Vs Wasted Traffic. In: 22nd International Teletraffic Congress Specialist Seminar on Energy Efficient and Green Networking. Christchurch, New Zealand 2013. Volltext BIB Download Details
  • Schwartz, Christian; Lehrieder, Frank; Wamser, Florian; Hoßfeld, Tobias; Tran-Gia, Phuoc: Smart-Phone Energy Consumption Vs. 3G Signaling Load: The Influence of Application Traffic Patterns. In: Tyrrhenian International Workshop 2013 on Digital Communications: Green ICT. Genova, Italy 2013. Volltext BIB Download Details
  • Schwartz, Christian; Hossfeld, Tobias; Lehrieder, Frank; Tran-Gia, Phuoc: Angry Apps: When Smartphone Users and Mobile Operators Get Annoyed. In: Journal of Computer Networks and Communications, Jg. 176217 (2013). Volltext BIB Download Details
  • Zinner, Thomas; Hossfeld, Tobias; Tran-Gia, Phuoc; Kellerer, Wolfgang: Software defined Networks - Das Internet flexibler gestalten und dynamischer steuern. In: ITG Mitgliederbeilage / VDE dialog (invited article) (2013). Volltext BIB Download Details
  • Varela, Martin; Mäki, Toni; Skorin-Kapov, Lea; Hoßfeld, Tobias: Towards an understanding of visual appeal in website design. In: Fifth International Workshop on Quality of Multimedia Experience (QoMEX 2013). Klagenfurt, Austria 2013. Volltext BIB Download Details
  • Varela, Martin; Mäki, Toni; Skorin-Kapov, Lea; Hoßfeld, Tobias: Increasing Payments in Crowdsourcing: Don’t look a gift horse in the mouth. In: 4th International Workshop on Perceptual Quality of Systems (PQS 2013). Vienna, Austria 2013. Volltext BIB Download Details
  • Tran-Gia, Phuoc; Hoßfeld, Tobias; Hartmann, Matthias; Hirth, Matthias: Crowdsourcing and its Impact on Future Internet Usage. In: it - Information Technology, Jg. 55 (2013). Volltext BIB Download Details
  • Stiller, Burkhard; Hausheer, David; Hoßfeld, Tobias: Towards a Socially-Aware Management of New Overlay Application Traffic Combined with Energy Efficiency in the Internet (SmartenIT). In: Alex Galis, Anastasius Gavras (Hrsg) (Hrsg.): The Future Internet. Springer, LNCS 7858, 2013. Volltext BIB Download Details
  • Sieber, Christian; Hoßfeld, Tobias; Zinner, Thomas; Tran-Gia, Phuoc; Timmerer, Christian: Implementation and User-centric Comparison of a Novel Adaptation Logic for DASH with SVC. In: IFIP/IEEE International Workshop on Quality of Experience Centric Management (QCMan). Ghent, Belgium 2013. Volltext BIB Download Details
  • Gardlo, Bruno; Ries, Michal; Hoßfeld, Tobias: Impact of Screening Technique on Crowdsourcing QoE Assessments. In: 22nd International Conference Radioelektronika 2012, Special Session on Quality in multimedia systems. Brno, Czech Republic 2012. Volltext BIB Download Details
  • Egger, Sebastian; Reichl, Peter; Hoßfeld, Tobias; Schatz, Raimund: Time is Bandwidth? Narrowing the Gap between Subjective Time Perception and Quality of Experience. In: 2012 IEEE International Conference on Communications (ICC 2012). Ottawa, Canada 2012. Volltext BIB Download Details
  • Egger, Sebastian; Hoßfeld, Tobias; Schatz, Raimund; Fiedler, Markus: Waiting Times in Quality of Experience for Web Based Services. In: QoMEX 2012. Yarra Valley, Australia 2012. Volltext BIB Download Details
  • Ciszkowski, Tomasz; Mazurczyk, Wojciech; Kotulski, Zbigniew; Hoßfeld, Tobias; Fiedler, Markus; Collange, Denis: Towards Quality of Experience-based Reputation Models for Future Web Service Provisioning. In: Special Issue of the Springer Telecommunication Systems Journal: Future Internet Services and Architectures - Trends and Visions, Jg. 51 (2012). Volltext BIB Download Details
  • Burger, Valentin; Lehrieder, Frank; Hoßfeld, Tobias; Seedorf, Jan: Who Profits from Peer-to-Peer File-Sharing? Traffic Optimization Potential in BitTorrent Swarms. In: International Teletraffic Congress (ITC 24). Krakow, Poland 2012. Volltext BIB Download Details
  • Hofeld, Tobias; Zinner, Thomas; Fiedler, Markus; Liers, Florian; Volkert, Thomas; Khondoker, Rahamatullah; Schatz, Raimund: Requirement Driven Prospects for Realizing User-Centric Network Orchestration. In: Computer Communications Journal Special Issue on Human-Centric Multimedia Networking (2012). Volltext BIB Download Details
  • Hofeld, Tobias; Schatz, Raimund: Quality of Experience of YouTube Video Streaming for Current Internet Transport Protocols. In: Computer Networks (2012). BIB Download Details
  • Hirth, Matthias; Lehrieder, Frank; Oberste-Vorth, Stephan; Hoßfeld, Tobias; Tran-Gia, Phuoc: Wikipedia and its Network of Authors from a Social Network Perspective. In: International Conference on Communications and Electronics (ICCE). Hue, Vietnam 2012. Volltext BIB Download Details
  • Hirth, Matthias; Hossfeld, Tobias; Tran-Gia, Phuoc: Analyzing Costs and Accuracy of Validation Mechanisms for Crowdsourcing Platforms. In: Mathematical and Computer Modelling (Elsevier) (2012). Volltext BIB Download Details
  • Gardlo, Bruno; Ries, Michal; Hoßfeld, Tobias; Schatz, Raimund: Microworkers vs. Facebook: The Impact of Crowdsourcing Platform Choice on Experimental Results. In: QoMEX 2012. Yarra Valley, Australia 2012. Volltext BIB Download Details
  • Hoßfeld, Tobias; Schatz, Raimund; Varela, Martin; Timmerer, Christian: Challenges of QoE Management for Cloud Applications. In: IEEE Communications Magazine, Jg. 50 (2012) Nr. 4. Volltext BIB Download Details
  • Hoßfeld, Tobias; Liers, Florian; Schatz, Raimund; Staehle, Barbara; Staehle, Dirk; Volkert, Thomas; Wamser, Florian: Quality of Experience Management for YouTube: Clouds, FoG and the AquareYoum. In: PIK - Praxis der Informationverarbeitung und -kommunikation (PIK), Jg. 35 (2012) Nr. 3. Volltext BIB Download Details
  • Hoßfeld, Tobias; Hirth, Matthias; Tran-Gia, Phuoc: Aktuelles Schlagwort: Crowdsourcing. In: Informatik Spektrum, Jg. 35 (2012) Nr. 3. Volltext BIB Download Details
  • Hoßfeld, Tobias; Egger, Sebastian; Schatz, Raimund; Fiedler, Markus; Masuch, Kathrin; Lorentzen, Charlott: Initial Delay vs. Interruptions: Between the Devil and the Deep Blue Sea. In: QoMEX 2012. Yarra Valley, Australia 2012. Volltext BIB Download Details
  • Zinner, Thomas; Klein, Dominik; Hoßfeld, Tobias: User-Centric Network-Application Interaction for Live HD Video Streaming. In: 4th International Conference on Mobile Networks and Management (MONAMI 2012). Hamburg, Germany 2012. Volltext BIB Download Details
  • Schwartz, Christian; Hofeld, Tobias; Lehrieder, Frank; Tran-Gia, Phuoc: Angry Apps: When Smartphone Users and Mobile Operators Get Annoyed. In: Journal of Computer Networks and Communications (JCNC): Special Issue on “Improving QoS and QoE for Mobile Communications” (2012). Volltext BIB Download Details
  • Schatz, Raimund; Hoßfeld, Tobias; Casas, Pedro: Passive YouTube QoE Monitoring for ISPs. In: Best Paper Award at Workshop on Future Internet and Next Generation Networks (FINGNet-2012). Palermo, Italy 2012. Volltext BIB Download Details
  • Lehrieder, Frank; Dán, György; Hoßfeld, Tobias; Oechsner, Simon; Singeorzan, Vlad: Caching for BitTorrent-like P2P Systems: A Simple Fluid Model and its Implications. In: IEEE/ACM Transactions on Networking (TON), Jg. 20 (2012) Nr. 4. Volltext BIB Download Details
  • Jarschel, Michael; Schlosser, Daniel; Scheuring, Sven; Hoßfeld, Tobias: Gaming in the clouds: QoE and the users’ perspective. In: Mathematical and Computer Modelling (Elsevier) (2012). Volltext BIB Download Details
  • Zinner, Thomas; Liers, Florian; Hoßfeld, Tobias; Rauscher, Dirk; Reuther, Bernd; Günther, Daniel; Volkert, Thomas; Fiedler, Markus: Prospects for Realizing User-Centric Network Orchestration: FEC-protected SVC Streaming. In: 7. GI/ITG KuVS Fachgespräch ’Future Internet’. München, Germany 2012. Volltext BIB Download Details
  • Hoßfeld, Tobias; Fiedler, Markus; Zinner, Thomas: The QoE Provisioning-Delivery-Hysteresis and Its Importance for Service Provisioning in the Future Internet. In: Proceedings of the 7th Conference on Next Generation Internet Networks (NGI). Kaiserslautern, Germany 2011. Volltext BIB Download Details
  • Hoßfeld, Tobias: Aktuelle Entwicklungen im Internet und sich daraus ergebende rechtliche Fragestellungen. In: Herczeg, Jiri; Grivna, Tomas (Hrsg) (Hrsg.): Internet-Kriminalität und die neuen Herausforderungen der Informationsgesellschaft des 21. Jahrhundert. Wolters Kluwer CR, 2011. Volltext BIB Download Details
  • Hirth, Matthias; Hoßfeld, Tobias; Tran-Gia, Phuoc: Cost-Optimal Validation Mechanisms and Cheat-Detection for Crowdsourcing Platforms. In: Workshop on Future Internet and Next Generation Networks (FINGNet). Seoul, Korea 2011. Volltext BIB Download Details
  • Hirth, Matthias; Hoßfeld, Tobias; Tran-Gia, Phuoc: Anatomy of a Crowdsourcing Platform - Using the Example of Microworkers.com. In: Workshop on Future Internet and Next Generation Networks (FINGNet). Seoul, Korea 2011. Volltext BIB Download Details
  • Fiedler, Markus; Hoßfeld, Tobias; Norros, Ilkka; Rodrigues, Joel; Pereira, Paulo Rogério: The Network of Excellence Euro-NF and its Specific Joint Research Projects. In: ICST Global Community Magazine (2011). BIB Download Details
  • Dan, György; Hoßfeld, Tobias; Oechsner, Simon; Cholda, Piotr; Stankiewicz, Rafal; Papafili, Ioanna; Stamoulis, George D.: Interaction Patterns between P2P Content Distribution Systems and ISPs. In: IEEE Communications Magazine, Jg. 49 (2011) Nr. 5. Volltext BIB Download Details
  • Hoßfeld, Tobias; Schatz, Raimund; Biedermann, Sebastian; Platzer, Alexander; Egger, Sebastian; Fiedler, Markus: The Memory Effect and Its Implications on Web QoE Modeling. In: 23rd International Teletraffic Congress (ITC 23). San Francisco, USA 2011. Volltext BIB Download Details
  • Hoßfeld, Tobias; Liers, Florian; Volkert, Thomas; Schatz, Raimund: FoG and Clouds: Optimizing QoE for YouTube. In: KuVS 5thGI/ITG KuVS Fachgespräch NG Service Delivery Platforms. Munich, Germany 2011. Volltext BIB Download Details
  • Hoßfeld, Tobias; Lehrieder, Frank; Hock, David; Oechsner, Simon; Despoto-vic, Zoran; Kellerer, Wolfgang; Michel, Maximilian: Characterization of BitTorrent Swarms and their Distribution in the Internet. In: Computer Networks, Jg. 55 (2011) Nr. 5. Volltext BIB Download Details
  • Hoßfeld, Tobias; Hirth, Matthias; Tran-Gia, Phuoc: Modeling of Crowdsourcing Platforms and Granularity of Work Organization in Future Internet. In: International Teletraffic Congress (ITC 23). San Francisco, USA 2011. Volltext BIB Download Details
  • Lehrieder, Frank; Oechsner, Simon; Hoßfeld, Tobias; Staehle, Dirk; Despotovic, Zoran; Kellerer, Wolfgang; Michel, Maximilian: Mitigating Unfairness in Locality-Aware Peer-to-Peer Networks. In: International Journal of Network Management (IJNM), Special Issue on Economic Traffic Management, Jg. 21 (2011) Nr. 1. Volltext BIB Download Details
  • Jarschel, Michael; Schlosser, Daniel; Scheuring, Sven; Hoßfeld, Tobias: An Evaluation of QoE in Cloud Gaming Based on Subjective Tests. In: Workshop on Future Internet and Next Generation Networks (FINGNet-2011). Seoul, Korea 2011. Volltext BIB Download Details
  • Hoßfeld, Tobias; Tran-Gia, Phuoc: EuroView 2010: Visions of Future Generation Networks. In: ACM SIGCOMM Computer Communications Review CCR, Jg. 41 (2011) Nr. 3. Volltext BIB Download Details
  • Hoßfeld, Tobias; Schatz, Raimund; Seufert, Michael; Hirth, Matthias; Zinner, Thomas; Tran-Gia, Phuoc: Quantification of YouTube QoE via Crowdsourcing. In: IEEE International Workshop on Multimedia Quality of Experience - Modeling, Evaluation, and Directions (MQoE 2011). Dana Point, CA, USA 2011. Volltext BIB Download Details
  • Hoßfeld, Tobias; Schatz, Raimund; Egger, Sebastian: SOS: The MOS is not enough!. In: QoMEX 2011. Mechelen, Belgium 2011. Volltext BIB Download Details
  • Stankiewicz, Rafal; Cholda, Piotr; Domzal, Jerzy; Wojcik, Robert; Hoßfeld, Tobias; Zinner, Thomas; Oechsner, Simon; Lehrieder, Frank: Influence of traffic management solutions on Quality of Experience for prevailing overlay applications. In: Proceedings of the 7th Conference on Next Generation Internet Networks (NGI). Kaiserslautern, Germany 2011. Volltext BIB Download Details
  • Meier, Sebastian; Barisch, Marc; Kirstädter, Andreas; Schlosser, Daniel; Duelli, Michael; Jarschel, Michael; Hoßfeld, Tobias; Hoffmann, Klaus; Hoffmann, Marco; Kellerer, Wolfgang; Khan, Ashiq; Jurca, Dan; Kozu, Kazuyuki: Provisioning and Operation of Virtual Networks. In: Electronic Communications of the EASST, Kommunikation in Verteilten Systemen 2011, Jg. 37 (2011). Volltext BIB Download Details
  • Schlosser, Daniel; Jarschel, Michael; Duelli, Michael; Hoßfeld, Tobias; Hoffmann, Klaus; Hoffmann, Marco; Morper, Hans Jochen; Jurca, Dan; Khan, Ashiq: A Use Case Driven Approach to Network Virtualization. In: accepted at IEEE Kaleidoscope 2010, published via OPUS Würzburg under OpenAccess. Würzburg, Germany 2010. Volltext BIB Download Details
  • Schlosser, D.; Hoffmann, M.; Hoßfeld, T.; Jarschel, M.; Kirstaedter, A.; Kellerer, W.; Köhler, S.: COMCON: Use Cases for Virtual Future Networks. In: TridentCom 2010. Berlin 2010. Volltext BIB Download Details
  • Oechsner, Simon; Zinner, Thomas; Prokopetz, Jochen; Hoßfeld, Tobias: Supporting Scalable Video Codecs in a P2P Video-on-Demand Streaming System. In: 21th ITC Specialist Seminar on Multimedia Applications - Traffic, Performance and QoE. Miyazaki, Jap 2010. Volltext BIB Download Details
  • Lehrieder, Frank; Oechsner, Simon; Hoßfeld, Tobias; Despotovic, Zoran; Kellerer, Wolfgang; Michel, Maximilian: Can P2P-Users Benefit from Locality-Awareness?. In: 10th IEEE International Conference on Peer-to-Peer Computing 2010 - IEEE P2P 2010. Best Paper Award, Delft, the Netherlands 2010. Volltext BIB Download Details
  • Lehrieder, Frank; Dán, György; Hoßfeld, Tobias; Oechsner, Simon; Singeorzan, Vlad: The Impact of Caching on BitTorrent-like Peer-to-peer Systems. In: 10th IEEE International Conference on Peer-to-Peer Computing 2010 - IEEE P2P 2010. Best Paper Award, Delft, the Netherlands 2010. Volltext BIB Download Details
  • Fiedler, Markus; Hoßfeld, Tobias; Tran-Gia, Phuoc: A Generic Quantitative Relationship between Quality of Experience and Quality of Service. In: IEEE Network: The Magazine of Global Internetworking, Jg. 24 (2010) Nr. 2. Volltext BIB Download Details
  • Fiedler, Markus; Hoßfeld, Tobias: Quality of Experience-Related Differential Equations and Provisioning-Delivery Hysteresis. In: to 21st ITC Specialist Seminar on Multimedia Applications - Traffic, Performance and QoE. Phoenix Seagaia Resort, Miyazaki, Japan 2010. Volltext BIB Download Details
  • Chołda, Piotr; Domzał, Jerzy; Wójcik, Robert; Stankiewicz, Rafał; Lehrieder, Frank; Hoßfeld, Tobias; Oechsner, Simon; Singeorzan, Vlad: Performance Evaluation of P2P Caches: Flash-Crowd Case. In: Australasian Telecommunication Networks and Applications Conference (ATNAC) 2010. Auckland, New Zealand 2010. Volltext BIB Download Details
  • Zinner, Thomas; Hoßfeld, Tobias; Minash, Tahir Nawaz; Fiedler, Markus: Controlled vs. Uncontrolled Degradations of QoE - The Provisioning-Delivery Hysteresis in Case of Video. In: New Dimensions in the Assessment and Support of Quality of Experience (QoE) for Multimedia Applications. Tampere 2010. Volltext BIB Download Details
  • Zinner, Thomas; Hohlfeld, Oliver; Abboud, Osama; Hoßfeld, Tobias: Impact of Frame Rate and Resolution on Objective QoE Metrics. In: International Workshop on Quality of Multimedia Experience, 2010. Trondheim 2010. Volltext BIB Download Details
  • Zinner, Thomas; Abboud, Osama; Hohlfeld, Oliver; Hoßfeld, Tobias; Tran-Gia, Phuoc: Towards QoE Management for Scalable Video Streaming. In: 21th ITC Specialist Seminar on Multimedia Applications - Traffic, Performance and QoE. Miyazaki, Jap 2010. Volltext BIB Download Details
  • Stiller, Burkhard; Hoßfeld, Tobias; Stamoulis, George D. (Hrsg) (Hrsg.): Incentives, Overlays, and Economic Traffic Control. Springer, Amsterdam, The Netherlands 2010. BIB Download Details
  • Hoßfeld, Tobias; Duelli, Michael; Staehle, Dirk; Tran-Gia, Phuoc: Chapter VIII: Cooperation Strategies for P2P Content Distribution in Cellular Mobile Networks: Considering Mobility and Heterogeneity. In: Seet, Boon-Chong (Hrsg) (Hrsg.): Mobile Peer-to-Peer Computing for Next Generation Distributed Environments: Advancing Conceptual and Algorithmic Applications. IGI Global, 2009, S. 1234-1234. Volltext BIB Download Details
  • Ciszkowski, Tomasz; Mazurczyk, Wojciech; Kotulski, Zbigniew; Hoßfeld, Tobias; Fiedler, Markus; Collange, Denis: Towards Quality of Experience-based Reputation Models for Future Web Service Provisioning. In: Future Internet Architectures: New Trends in Service Architectures (2nd Euro-NF Workshop). Santander, Spain 2009. Volltext BIB Download Details
  • Berl, Andreas; Meer, Hermann de; Hoßfeld, Tobias: P2P Solutions for Cellular Networks. In: International Conference on Advances in P2P Systems (AP2PS 2009). Sliema, Malta 2009. Volltext BIB Download Details
  • Schlosser, Daniel; Hoßfeld, Tobias: Service Oriented Network Framework Enabling Global QoS and Network Virtualization. In: ITC SS 2009. Hoi An 2009. Volltext BIB Download Details
  • Schlosser, Daniel; Hoßfeld, Tobias: Mastering Selfishness and Heterogeneity in Mobile P2P Content Distribution Networks with Multiple Source Download in Cellular Networks. In: Peer-to-Peer Networking and Applications, Special Issue on Mobile P2P Networking and Computing, Jg. 2 (2009) Nr. 3. Volltext BIB Download Details
  • Oechsner, Simon; Lehrieder, Frank; Hoßfeld, Tobias; Metzger, Florian; Pussep, Konstantin; Staehle, Dirk: Pushing the Performance of Biased Neighbor Selection through Biased Unchoking. In: 9th International Conference on Peer-to-Peer Computing. Seattle, USA 2009. Volltext BIB Download Details
  • Oechsner, Simon; Hoßfeld, Tobias; Tran-Gia, Phuoc: Performance Evaluation of a Distributed Lookup System for a Virtual Database Server. In: 20th ITC Specialist Seminar. Hoi An, Vietnam 2009. Volltext BIB Download Details
  • Hung, Nguyen Chan; Hoßfeld, Tobias; Hoang, Giang Ngo; Vinh, Vu Thanh; Thang, Nguyen Manh: Challenges in the Development of Mobile P2P Applications and Services. In: Vietname Journal on Information and Communication Technologies (2009) Nr. 2. Volltext BIB Download Details
  • Hoßfeld, Tobias; Schlosser, Daniel; Tutschku, Kurt; Tran-Gia, Phuoc: Chapter VII: Cooperation Strategies for P2P Content Distribution in Cellular Mobile Networks: Considering Selfishness and Heterogeneity. In: Seet, Boon-Chong (Hrsg) (Hrsg.): Mobile Peer-to-Peer Computing for Next Generation Distributed Environments: Advancing Conceptual and Algorithmic Applications. IGI Global, 2009. Volltext BIB Download Details
  • Hoßfeld, Tobias; Leibnitz, Kenji; Nakao, Akihiro: Modeling of Modern Router Architectures Supporting Network Virtualization. In: 2nd International Workshop on the Network of the Future (FutureNet II) in conjunction with IEEE GLOBECOM 2009. Honolulu, Hawaii 2009. Volltext BIB Download Details
  • Hoßfeld, Tobias; Hausheer, David; Hecht, Fabio; Lehrieder, Frank; Oechsner, Simon; Papafili, Ioanna; Racz, Peter; Soursos, Sergios; Staehle, Dirk; Stamoulis, George D.; Tran-Gia, Phuoc; Stiller, Burkhard: An Economic Traffic Management Approach to Enable the TripleWin for Users, ISPs, and Overlay Providers. In: Tselentis, Georgios; Domingue, John; Galis, Alex; Gavras, Anastasius; Hausheer, David; Krco, Srdjan; Lotz, Volkmar; Zahariadis, Theodore (Hrsg) (Hrsg.): FIA Prague Book. IOS Press Books Online, Towards the Future Internet - A European Research Perspective 2009, S. 24-24. Volltext BIB Download Details
  • Stiller, Burkhard; Hausheer, David; Hoßfeld, Tobias; Liotta, Antonio; Spirou, Spiros; Waldburger, Martin: A Discussion of Socio-economic Management and Incentives for the Future Internet. In: 2nd International Workshop on the Network of the Future (FutureNet II) in conjunction with IEEE GLOBECOM 2009. Honolulu, Hawaii 2009. Volltext BIB Download Details
  • Tran-Gia, Phuoc; Hoßfeld, Tobias; Menth, Michael; Pries, Rastin: Emerging Issues in Current Future Internet Design. In: e&i Elektrotechnik und Informationstechnik, Special Issue ’Future Internet’, ISSN: 0932-383X (print), ISSN: 1613-7620 (online), Jg. 126 (2009) Nr. 7-8. Volltext BIB Download Details
  • Tutschku, Kurt; Berl, Andreas; Hoßfeld, Tobias; Meer, Hermann de: Chapter XVI: Mobile P2P in Cellular Mobile Networks: Architecture and Performance. In: Seet, Boon-Chong (Hrsg) (Hrsg.): Mobile Peer-to-Peer Computing for Next Generation Distributed Environments: Advancing Conceptual and Algorithmic Applications. IGI Global, 2009. Volltext BIB Download Details
  • Juan Pedro Fernandez-Palacios Gimenez; Maria Angeles Callejo Rodriguez; Hasan, Hasan; Hoßfeld, Tobias; Staehle, Dirk; Despotovic, Zoran; Kellerer, Wolfgang; Pussep, Konstantin; Papafili, Ionna; Stamoulis, George D.; Stiller, Burkhard: A New Approach for Managing Traffic of Overlay Applications of the SmoothIT Project. In: 2nd International Conference on Autonomous Infrastructure, Management and Security (AIMS 2008). Bremen, Germany 2008. Volltext BIB Download Details
  • Hoßfeld, Tobias; Leibnitz, Kenji; Remiche, Marie-Ange: Exact Sojourn Time Distribution in an Online IPTV Recording Service. In: 15th International Conference on Analytical and Stochastic Modelling Techniques and Applications (ASMTA 2008). Nicosia, Cyprus 2008. Volltext BIB Download Details
  • Hoßfeld, Tobias; Leibnitz, Kenji: Performance Modeling of Data Aggregation in Wireless Sensor Networks. In: Invited Paper at the Jointly-organized Symposium of the Institute of Intelligent Information and Communications Technology (IICT) at Konan University and the ORSJ (Operations Research Society of Japan). Kobe, Japan 2008. Volltext BIB Download Details
  • Hoßfeld, Tobias; Leibnitz, Kenji: A Qualitative Measurement Survey of Popular Internet-based IPTV Systems. In: Second International Conference on Communications and Electronics (HUT-ICCE 2008). Hoi An, Vietnam 2008. Volltext BIB Download Details
  • Hoßfeld, Tobias; Hock, David; Tran-Gia, Phuoc; Tutschku, Kurt; Fiedler, Markus: Testing the IQX Hypothesis for Exponential Interdependency between QoS and QoE of Voice Codecs iLBC and G.711. In: 18th ITC Specialist Seminar on Quality of Experience. Karlskrona, Sweden 2008. Volltext BIB Download Details
  • Hoßfeld, Tobias; Binzenhöfer, Andreas: Analysis of Skype VoIP Traffic in UMTS: End-to-End QoS and QoE Measurements. In: Computer Networks: The International Journal of Computer and Telecommunications Networking, Jg. 52 (2008) Nr. 3. Volltext BIB Download Details
  • Binzenhöfer, Andreas; Hoßfeld, Tobias; Kunzmann, Gerald; Eger, Kolja: Efficient Simulation of Large-Scale P2P Networks. In: International Journal of Computational Science and Engineering (IJCSE): Special Issue on Parallel, Distributed and Network-Based Processing (2008). BIB Download Details
  • Oechsner, Simon; Soursos, Sergios; Papafili, Ioanna; Hoßfeld, Tobias; Stamoulis, George D.; Stiller, Burkhard; Callejo, Maria Angeles; Staehle, Dirk: A framework of economic traffic management employing self-organization overlay mechanisms. In: IWSOS’08. Vienna, Austria 2008. Volltext BIB Download Details
  • Zinner, Thomas; Hoßfeld, Tobias; Oechsner, Simon; Tran-Gia, Phuoc: On the Trade-off between Efficiency and Congestion in Location-aware Overlay Networks - Example of a Vertical Handover Support System. In: Eighth International Conference on Peer-to-Peer Computing (P2P 2008). Aachen, Germany 2008. Volltext BIB Download Details
  • Stiller, Burkhard; Hoßfeld, Tobias: Modeling of P2P-based Video Streaming. In: Joint EC-GIN, EMANICS, and SmoothIT Workshop Economic Traffic Management. Zurich, Switzerland 2008. BIB Download Details
  • Staehle, Barbara; Hoßfeld, Tobias; Vicari, Norbert; Kuhnert, Matthias: A Cross-Layer Approach for Enabling Low Duty Cycled ZigBee Mesh Sensor Networks. In: International Symposium on Wireless Pervasive Computing 2008. Santorini, Greece 2008. Volltext BIB Download Details
  • Binzenhöfer, Andreas; Hoßfeld, Tobias; Kunzmann, Gerald; Eger, Kolja: Efficient Simulation of Large-Scale P2P Networks: Compact Data Structures. In: Workshop on Modeling, Simulation and Optimization of Peer-to-peer environments (MSOP2P) in conjunction with Euromicro (PDP 2007). Naples, Italy 2007. Volltext BIB Download Details
  • Hoßfeld, Tobias; Leibnitz, Kenji: Modeling and Evaluation of an Online TV Recording Service. In: Ninth annual workshop on mathematical performance modeling and analysis MAMA2007, in conjunction with ACM SIGMETRICS ’07 and FCRC ’07. San Diego, CA, USA 2007. Volltext BIB Download Details
  • Eger, Kolja; Hoßfeld, Tobias; Binzenhöfer, Andreas; Kunzmann, Gerald: Efficient Simulation of Large-Scale P2P Networks: Packet-level vs. Flow-level Simulations. In: 2nd Workshop on the Use of P2P, GRID and Agents for the Development of Content Networks (UPGRADE-CN’07) in conjunction with the 16th IEEE HPDC. Monterey Bay, California, USA 2007. Volltext BIB Download Details
  • Duelli, Michael; Hoßfeld, Tobias; Staehle, Dirk: Impact of Vertical Handovers on Cooperative Content Distribution Systems. In: Seventh IEEE International Conference on Peer-to-Peer Computing (P2P2007). Best Student Paper, Galway, Ireland 2007, S. 177-177. Volltext BIB Download Details
  • Hoßfeld, Tobias; Leibnitz, Kenji: Performance Evaluation of an IPTV Recording Service. In: Invited Paper at the Jointly-organized Symposium of the Institute of Intelligent Information and Communications Technology (IICT) at Konan University and the ORSJ (Operations Research Society of Japan). Kobe, Japan 2007. Volltext BIB Download Details
  • Hoßfeld, Tobias; Leibnitz, Kenji; Remiche, Marie-Ange: Modeling of an Online TV Recording System. In: ACM SIGMETRICS Performance Evaluation Review, Jg. 35 (2007) Nr. 2. Volltext BIB Download Details
  • Hoßfeld, Tobias; Tran-Gia, Phuoc; Fiedler, Markus: Quantification of Quality of Experience for Edge-Based Applications. In: 20th International Teletraffic Congress (ITC20). Ottawa, Canada 2007. Volltext BIB Download Details
  • Staehle, Barbara; Hoßfeld, Tobias; Kuhnert, Matthias; Vicari, Norbert: Enabling the Sleep Mode in Non-beaconed 802.15.4 Multihop Networks - A Simulative Investigation. In: 6. GI/ITG KuVS Fachgespräch Drahtlose Sensornetze. Aachen, Germany 2007. Volltext BIB Download Details
  • Leibnitz, Kenji; Hoßfeld, Tobias; Wakamiya, Naoki; Murata, Masayuki: Peer-to-Peer vs. Client/Server: Reliability and Efficiency of a Content Distribution Service. In: 20th International Teletraffic Congress (ITC20). Ottawa, Canada 2007. Volltext BIB Download Details
  • Kunzmann, Gerald; Nagel, Robert; Hoßfeld, Tobias; Binzenhöfer, Andreas; Eger, Kolja: Efficient Simulation of Large-Scale P2P Networks: Modeling Network Transmission Times. In: Workshop on Modeling, Simulation and Optimization of Peer-to-peer environments (MSOP2P) in conjunction with Euromicro (PDP 2007). Naples, Italy 2007. Volltext BIB Download Details
  • Hoßfeld, Tobias; Binzenhöfer, Andreas; Fiedler, Markus; Tutschku, Kurt: Measurement and Analysis of Skype VoIP Traffic in 3G UMTS Systems. In: 4th International Workshop on Internet Performance, Simulation, Monitoring and Measurement (IPS-MoMe 2006). Salzburg, Austria 2006. Volltext BIB Download Details
  • Andreas Binzenhöfer und Tobias Hoßfeld: Warum Panini Fußballalben auch Informatikern Spaß machen. In: Weigand, Hans-Georg (Hrsg) (Hrsg.): Fußball eine Wissenschaft für sich. Verlag Königshausen & Neumann, 2006, S. 10-10. Volltext BIB Download Details
  • Andersen, Frank-Uwe; Tutschku, Kurt; Hoßfeld, Tobias; Oechsner, Simon: Verlässliche Peer-to-Peer Technologie als Steuerungsverfahren für zukünftige mobile Zugangsnetze. In: 11. ITG-Mobilfunktagung, Technologien und Anwendungen, ISBN 3-8007-2942-3. Osnabrück, Germany 2006. BIB Download Details
  • Leibnitz, Kenji; Hoßfeld, Tobias; Wakamiya, Naoki; Murata, Masayuki: Modeling of Epidemic Diffusion in Peer-to-Peer File-Sharing Networks. In: The Second International Workshop on Biologically Inspired Approaches to Advanced Information Technology, Bio-ADIT 2006, LNCS 3853. Senri Life Science Center, Osaka, Japan 2006. Volltext BIB Download Details
  • Hoßfeld, Tobias; Oechsner, Simon; Tutschku, Kurt; Andersen, Frank-Uwe; Caviglione, Luca: Supporting Vertical Handover by Using a Pastry Peer-to-Peer Overlay Network. In: Mobile Peer-to-Peer Computing MP2P’06, in conjunction with the 4th IEEE International Conference on Pervasive Computing and Communications (PerCom’06). Pisa, Italy 2006. Volltext BIB Download Details
  • Hoßfeld, Tobias; Oechsner, Simon; Tutschku, Kurt; Andersen, Frank-Uwe: Evaluation of a Pastry-based P2P Overlay for Supporting Vertical Handover. In: IEEE Wireless Communications and Networking Conference. Las Vegas, NV, USA 2006, S. 6-6. Volltext BIB Download Details
  • Hoßfeld, Tobias; Mäder, Andreas; Tutschku, Kurt; Andersen, Frank-Uwe: Time-Discrete Analysis of the Crawling Strategy in an Optimized Mobile P2P Architecture. In: EuroNGI Workshop on. Loveno di Menaggio, Como, Italy 2006. Volltext BIB Download Details
  • Hoßfeld, Tobias; Mäder, Andreas; Staehle, Dirk: When Do We Need Rate Control for Dedicated Channels in UMTS?. In: 2006 IEEE 63rd Vehicular Technology Conference. Melbourne, Australia 2006. Volltext BIB Download Details
  • Leibnitz, Kenji; Hoßfeld, Tobias; Wakamiya, Naoki; Murata, Masayuki: On Pollution in eDonkey-like Peer-to-Peer File-Sharing Networks. In: 13th GI/ITG Conference on Measurement, Modeling, and Evaluation of Computer and Communication Systems, MMB2006. Nürnberg, Germany 2006. Volltext BIB Download Details
  • Mäder, Andreas; Wagner, Bartosz; Hoßfeld, Tobias; Staehle, Dirk; Barth, Hans: Measurements in a Laboratory UMTS Network with time-varying Loads and different Admission Control Strategies. In: 4th International Workshop on Internet Performance, Simulation, Monitoring and Measurement. Salzburg, Austria 2006. Volltext BIB Download Details
  • Oechsner, Simon; Hoßfeld, Tobias; Tutschku, Kurt; Andersen, Frank-Uwe: Supporting Vertical Handover by a Self-Organizing Multi-Dimensional P2P Overlay. In: 2006 IEEE 63rd Vehicular Technology Conference. Melbourne, Australia 2006. Volltext BIB Download Details
  • Oechsner, Simon; Hoßfeld, Tobias; Tutschku, Kurt; Andersen, Frank-Uwe; Caviglione, Luca: Using Kademlia for the Configuration of B3G Radio Access Nodes. In: Mobile Peer-to-Peer Computing MP2P’06, in conjunction with the 4th IEEE International Conference on Pervasive Computing and Communications (PerCom’06). Pisa, Italy 2006. Volltext BIB Download Details
  • Pries, Rastin; Hoßfeld, Tobias; Tran-Gia, Phuoc: On the Suitability of the Short Message Service for Emergency Warning Systems. In: 2006 IEEE 63rd Vehicular Technology Conference. Melbourne, Australia 2006. Volltext BIB Download Details
  • Schlosser, Daniel; Hoßfeld, Tobias; Tutschku, Kurt: Comparison of Robust Cooperation Strategies for P2P Content Distribution Networks with Multiple Source Download. In: Sixth IEEE International Conference on Peer-to-Peer Computing (P2P2006). Cambridge, UK 2006. Volltext BIB Download Details
  • Hoßfeld, Tobias; Mäder, Andreas; Tutschku, Kurt; Tran-Gia, Phuoc; Andersen, Frank-Uwe; Meer, Hermann de; Dedinski, Ivan: Comparison of Crawling Strategies for an Optimized Mobile P2P Architecture. In: 19th International Teletraffic Congress (ITC19). Beijing, China 2005. Volltext BIB Download Details
  • Hoßfeld, Tobias; Staehle, Dirk: A Hybrid Model of the UMTS Downlink Capacity with WWW Traffic on Dedicated Channels. In: Mobile and Wireless Systems, LNCS 3427. Dagstuhl, Germany 2005, S. 20-20. Volltext BIB Download Details
  • Hoßfeld, Tobias; Tutschku, Kurt; Andersen, Frank-Uwe: Mapping of File-Sharing onto Mobile Environments: Enhancement by UMTS. In: Mobile Peer-to-Peer Computing MP2P, in conjunction with the 3rd IEEE International Conference on Pervasive Computing and Communications (PerCom’05). Kauai Island, Hawaii 2005. Volltext BIB Download Details
  • Hoßfeld, Tobias; Tutschku, Kurt; Andersen, Frank-Uwe: Mapping of File-Sharing onto Mobile Environments: Feasibility and Performance of eDonkey with GPRS. In: WCNC 2005. New Orleans, LA USA 2005. Volltext BIB Download Details
  • Oberender, Jens; Andersen, Frank-Uwe; Meer, Hermann de; Dedinski, Ivan; Hoßfeld, Tobias; Kappler, Cornelia; Mäder, Andreas; Tutschku, Kurt: Enabling Mobile Peer-to-Peer Networking. In: Mobile and Wireless Systems, LNCS 3427. Dagstuhl, Germany 2005. Volltext BIB Download Details
  • Hoßfeld, Tobias; Tutschku, Kurt; Schlosser, Daniel: Influence of the Size of Swapping Entities in Mobile P2P File-Sharing Networks. In: Peer-to-Peer-Systeme und -Anwendungen. GI/ITG-Workshop in Kooperation mit KiVS 2005, Kaiserslautern 2005. Volltext BIB Download Details
  • Hoßfeld, Tobias; Tutschku, Kurt; Andersen, Frank-Uwe; Meer, Hermann de; Oberender, Jens: Simulative Performance Evaluation of a Mobile Peer-to-Peer File-Sharing System. In: Next Generation Internet Networks NGI2005. Rome, Italy 2005. Volltext BIB Download Details
  • Hoßfeld, Tobias; Leibnitz, Kenji; Pries, Rastin; Tutschku, Kurt; Tran-Gia, Phuoc; Pawlikowski, Krzysztof: Information Diffusion in eDonkey Filesharing Networks. In: ATNAC 2004. Sydney, Australia 2004, S. 8-8. Volltext BIB Download Details
  • Metzger, Florian; Hoßfeld, Tobias; Steindl, Christoph: A Simulation Framework for Evaluating the QoS and QoE of TCP-based Streaming in an LTE Network. In: Proceedings of the 27th International Teletraffic Congress (ITC 27). Ghent, Belgium . Volltext BIB Download Details
  • (Hrsg.): Proceedings of The 28th International Teletraffic Congress 2016 (ITC 28) "Digital Connected World". . BIB Download Details