Subproject PDC2.1: QoS Differentiation Mechanisms: Scheduling Algorithms
This subproject focuses on scalable traffic management mechanisms for QoS support. If traffic streams with different traffic characteristics and QoS requirements are sharing common resources, a crucial task is the allocation of those resources to (groups of) users, for instance voice users vs. data users. An important example of these relates to scheduling algorithms such as weighted fair queuing.

Subproject PDC2.2: QoS Differentiation Mechanisms: Pricing
This subproject concentrates on distributed (and hence scalable) techniques that reveal the current network status (i.e., the level of congestion) to the end users. These end users decide how to react to these congestion signals. A strong focus is on pricing issues. It is clear that the support of differentiated QoS is useless if this is not reflected by differentiation of the corresponding prices: if different QoS levels would be charged in the same way, all users would opt for the premium quality service class.

Industrial cooperation
Many of the research results are the result of intensive and fruitful collaborations industrial parties. With Alcatel Lucent Bell Labs on performance enhancements for mobile networks concurrent access, and on the identification of a service-level calculus for large-scale real-time applications. We are currently starting up collaboration with IBM Netherlands on performance problems in Service-Oriented Architectures. Recently, we have started a new collaboration with Philips Research on modelling the performance of multi-hop mesh networks.

International cooperation
In the context of BRICKS we actively collaborate with a wide variety of internationally well-renowned research institutes, including for example INRIA Sophia Antipolis, CNRS, Columbia University, IBM Thomas J. Watson Center, Georgia Tech, France Telecom R&D, University of Washington, Hebrew University, VTT, Blekinge Institute of Technology, University of Geneva and Lucent Technologies Bell Labs.

Highlights 2004-2006
Research highlights
A variety of ground-breaking research results have been obtained in many areas, including the following:

• Optimal delay-based scheduling in communication networks
• Identification of the SLA negotiation space for realizing end-to-end QoS for Web-based services in multi-provider environments
• Exact asymptotics for Discriminatory Process Sharing models
• Identification of a pricing structure to provide incentives to enforce a suitable prioritization in a distributed manner
• Asymptotics for models with heavy-tailed service-time distributions

Economic & societal impact
Many of the research results are the result of intensive and fruitful collaborations with industrial parties, which use the results to enhance their competitive edge. In this way, the results have a significant impact on society. Foundation of E-Quality knowledge Center CWI, TU/e, UT and TNO are co-founders of the knowledge center E-Quality (founded in 2005), an initiative to combine the forces of the leading QoS research groups in the Netherlands to strengthen the relations with ICT companies, both nationally and internationally.

Future work 2007-2009
The project has enabled the partners to expand the international research networks over the past few years, which has led to new and fruitful national and international collaboration. Topics that will be addressed over the next few years include the development of both economic and performance models in the context over concurrent access for mobile networks in a multi-party environment, the development of models and techniques to provision for end-to-end Quality of Service of next-generation compositional services, performance models for wireless multi-hop mesh networks, amongst many others.

For more information, please refer to the publications and posters of this project.