Evolution of Internet Applications and
Internet Technologies

The Internet offers an increasing diversity of distributed applications and services over various media and enables new markets and Internet economy. Major Internet applications comprise information dissemination over the world-wide web, content distribution like BitTorrent P2P file-sharing, video delivery like YouTube HTTP video streaming, collaboration and interaction between humans like Facebook social networking or crowdsourcing as newly emerging service platform and business model in the Internet [3]. Thereby, services are often shifted to the cloud which result into novel technical challenges and impacts the user perceived QoE [4]. The migration to the cloud and the integration of human workforce by means of crowdsourcing increases the flexibility and the development of new Internet services [7].

Understanding and measuring quality of Internet services and underlying networks from an end-user perspective has attracted increased attention. This development has not only been driven by general trends such as the ’rise of the consumer’ and the related emergence of the ’experience economy’ [6]. In the Internet it is mainly a consequence of increasing competition amongst stakeholders in the ICT, media and entertainment markets, the proliferation of resource intensive services (such as YouTube video delivery) and the ever-present risk of customer churn caused by inadequate service quality [1]. These trends create conflicting, challenging demands on the network operators and service providers involved: on the one hand, they need to develop and offer sophisticated high-performance infrastructures and services that enable high quality experiences that lead to customer satisfaction and loyalty. On the other hand, they have to operate on a profitable basis in order to remain successful in the long run.

Quality of Experience

Being linked very closely to the subjective perception of the end user, QoE is supposed to enable a holistic understanding of the qualitative performance of networked communication systems and thus to complement the traditional, more technology-centric Quality of Service (QoS) perspective [6]. In the Research Topic"Quality of Experience" , the user’s satisfaction or degree of delight with a particular application is discussed. In the context of communication services, QoE is influenced by content, network, device, application, user expectations and goals, and context of use. Technical degradation in Quality of Service (QoS) may lead to strong decrease in subjective QoE. To this end, generic relationships between QoE and its influence factors as well as concrete QoE models for Internet applications are provided. As fundamental for the models, subjective user studies need to be carried out. A novel methodology for the execution of user studies via crowdsourcing is further developed. These QoE models are fundamental to analyze existing applications and services, to identify challenges and existing problems and to derive solutions for optimized service delivery from the user’s point of view.

Management of Internet Applications

The Research Topic "Management of Internet Applications"investigates the management of Internet applications to resolve the following central dilemma: the delivery of applications to the end user at maximum quality, while at the same time minimizing the costs of the stakeholders involved. However, the Internet itself is dramatically changing both in an economic way and in a technical way. The application of the Web 2.0 paradigm empowered Internet users to become application and service developers themselves. Examples of this new generation of websites are blogs, wikis and media-sharing platforms. Thereby users are connected to each other by means of social networks creating new paths for communication and the sharing of information and user-generated contents. Prominent examples of such social media networks are Facebook or YouTube. In particular, video streaming currently dominates global Internet traffic and accounts for the majority of consumer Internet traffic. We investigate QoE management approaches for Internet video services to cope with the increasing application demands. The rise of the peer-to-peer (P2P) paradigm led to new applications and services which allowed Internet users to share files and user-generated content amongst each other. In a P2P network, the nodes of this network, called peers, share common resources, e.g. bandwidth or memory, in order to provide or support a certain service, like content distribution. Typically, the peers form an overlay for communicating with each other. An overlay or an overlay network is a flexible, logical network that is built on top of an existing substrate network. Overlays are used to overcome technical limitations of the Internet or to facilitate simplified implementation of sophisticated new mechanisms on a logical layer. However, these same features create new difficulties for network and Internet Service Providers. Overlay connections used by the P2P networks are up to now generally network agnostic, wasteful with resources and complicate end-to-end traffic management [5]. My research identifies the above mentioned problems by measuring and modeling the merging overlay topology of a P2P content distribution network. Economic traffic management mechanisms [2] are provided which improve P2P performance and QoE while lowering ISP costs.

Emerging Internet Technologies and Applications

"Emerging Internet Technologies" and "Novel Internet Applications and Services"discusses emerging Internet technologies and applications. From a technological point of view, additional paradigms are currently established in the Internet or discussed in the research community. To this end, current Internet developments are discussed that are a new Internet protocol layering concept and virtualization as technological solution for its implementation. Beyond the technical aspects, the focus is on the following emerging applications and services. First, the migration of services to the cloud and their impact on QoE management for the corresponding cloud applications is highlighted. Then, crowdsourcing platforms are revisited as newly emerging service platform and business model on the Internet. The technological advances also lead to new applications like mobile crowdsourcing or the interconnection of human and machine clouds. Due to the size of these networks and human clouds, these platforms may have a huge impact on the Internet and on society, and will be a guiding paradigm that can form the evolution of work in the next years. Although the current amount of crowdsourcing traffic is still relatively small, there is a significant growth of crowdsourcing in terms of number of users, platforms, and data to be transmitted. Thus it is an important telecommunications priority to model and analyze these communication platforms and evolving complex networks, for example the dynamics and growth. Inspired from statistical physics, we introduce a quantity called entropy production to characterize the stationary properties of arbitrary social networks. The exploitation of such meta-information by network operators can lead to socially-aware traffic management mechanisms that lead to more sophisticated traffic management, reduction of the traffic load on the inter-domain links, and a reduction of the operating costs for the ISPs.

Ongoing Research

The content of my research will consequently be on the modeling and analysis of Internet applications. This covers the development of interdisciplinary evaluation models considering human centric QoE as well as economic and technical performance measures on network, application and service level. These models are then applied to analyze, optimize and manage application-layer traffic to the benefits of users and service providers in various application domains. The joint integration of technological advances and application-specific developments will lead to successful future Internet applications and services.


[1] Markus Fiedler, Tobias Hoßfeld, and Phuoc Tran-Gia. A Generic Quantitative Relationship between Quality of Experience and Quality of Service. IEEE Network: TheMagazine of Global Internetworking, 24, March 2010.

[2] Tobias Hoßfeld, David Hausheer, Fabio Hecht, Frank Lehrieder, Simon Oechsner, Ioanna Papafili, Peter Racz, Sergios Soursos, Dirk Staehle, George D. Stamoulis, Phuoc Tran-Gia, and Burkhard Stiller. An Economic Traffic Management Approach to Enable the TripleWin for Users, ISPs, and Overlay Providers. In Georgios Tselentis, John Domingue, Alex Galis, Anastasius Gavras, David Hausheer, Srdjan Krco, Volkmar Lotz, and Theodore Zahariadis, editors, FIA Prague Book, page 24. IOS Press Books Online, Towards the Future Internet - A European Research Perspective, May 2009.

[3] Tobias Hoßfeld, Matthias Hirth, and Phuoc Tran-Gia. Aktuelles Schlagwort: Crowdsourcing. Informatik Spektrum, 35, April 2012.

[4] Tobias Hoßfeld, Raimund Schatz, Martin Varela, and Christian Timmerer. Challenges of QoE Management for Cloud Applications. IEEE Communications Magazine, 50, April 2012.

[5] Frank Lehrieder, Simon Oechsner, Tobias Hoßfeld, Dirk Staehle, Zoran Despotovic, Wolfgang Kellerer, and Maximilian Michel. Mitigating Unfairness in Locality-Aware Peer-to-Peer Networks. International Journal of Network Management (IJNM), Special Issue on Economic Traffic Management, 21, January 2011.

[6] Raimund Schatz, Tobias Hoßfeld, Lucjan Janowski, and Sebastian Egger. From Packets to People: Quality of Experience as New Measurement Challenge. In Ernst Biersack, Christian Callegari, and Maja Matijasevic, editors, Data Traffic Monitoring and Analysis: From measurement, classification and anomaly detection to Quality of experience, Lecture Notes in Computer Science - Computer Communication Networks and Telecommunications. Springer, 2013 in press.

[7] Phuoc Tran-Gia, Tobias Hoßfeld, Matthias Hartmann, and Matthias Hirth. Crowdsourcing and its Impact on Future Internet Usage. it - Information Technology, 2013.