Johannes Kepler Universität Linz Institut für Telekooperation Altenberger Strasse 69 4040 Linz gabriele.kotsis <at> jku.ac.at www.tk.uni-linz.ac.at

Univ. Prof. Mag. Dr. Gabriele Kotsis

Next Generation Cooperative Environments –
A Quality of Service Perspective

Todays spectrum of options in mobile cooperation over distance ranges from portable computers connected to infrastucture networks via the air interface up to communication and computation devices seamlessly and transparently integrated into cooperative work environments. Besides the need for common standards and shared languages supporting information exchange (e.g. XML, RDF, CC/PP), a demand for a richer cooperation infrastructure can be observed.
Supporting such a cooperation (beyond pure communication) via shared artefacts, multi-user awareness and virtual presence raises a variety of both, technical as well as organizational questions.

From a technical point of view, the success of such mobile and wireless cooperation environments will depend on the quality of service (QoS) level at which they can be operated. The gap between the QoS demands of cooperative applications and the QoS that mobile and wireless networking technologies are able to deliver raises the need for QoS modeling and evaluation.

In the main part of this presentation, I will focus on performance evaluation techniques based on a user-oriented approach for characterising the load in mobile environments as a potential solution to this problem. Automated mechanisms for translating from a user-oriented view of the workload in the system to a resource oriented view will be presented and their importance for QoS mechanisms such as scheduling, admission control, load sharing, flow identification and traffic engineering will be assessed. Traditional traffic modelling approaches (from queuing theory and analytical performance engineering) will be contrasted with innovative techniques, including probabilistic attributed context free grammars as well as an event-based hierarchical modelling framework, which supports the integration of various modelling approaches (e.g. user behaviour graphs, markovian models, or process algebras).
Appropriateness of this framework will be demonstrated in an application scenario, where a simulation model is used to evaluate QoS in terms of user satisfaction in a video-conferencing environment.

Finally, I will envision, how performance engineering and adaptive QoS management will shape communication, collaboration, and coordination over QoS enablend networks (like IPv6) in forthcoming mobile multi-user cooperation environments.

Short Biography

Gabriele Kotsis is holding a full professor position in computer science at Johannes Kepler Universität Linz. She is chairing the Department of Telecooperation with a research focus in mobile computing, multimedia and hypermedia systems as well as cooperative and collaborative systems. Research in those areas includes the investigation of methods, techniques and tools for system development as well as evaluation and analysis with focus on performance evaluation. The Department is participating in numerous national and international projects, including CRUISE, a European network of excellence in sensor networks, EuroFGI, a network of excellence on Future Generation Internet, the AustrianGrid project, or ModelCVS a project on semantics in SW and system modelling, and actively involved in the organisation of international conferences, including for example iiWAS and MoMM.


Gabriele Kotsis, born on October 29th, 1967, in Vienna, Austria, started her scientific career at the University of Vienna. She received her masters degree (1991, honored with the Award of the Austrian Computer Society), her PhD (1995, honored with the Heinz-Zemanek Preis) and the venia docendi in computer science (2000) from the University of Vienna. Before joining JKU Linz in October 2002, she was working as a researcher and teacher at the University of Vienna (1991-2001), at the Vienna University for Economics and Business Administration (2001) and at the Copenhagen Business School (2002).


Prof. Kotsis is author of numerous publications in international conferences

and journals and is co-editor of several books. She is member of the OCG, the ACM and IEEE. From April 2003 to April 2007 she was president of the Austrian Computer Society.


Since October 2008 she is Vice Rector for Research at the Johannes Kepler University, Linz.