17th International workshop on Network and Operating Systems Support for Digital Audio & Video
Urbana-Champaign, IL, USA
June 4-5, 2007

Keynote Talk

    QoS in Wireless Mesh Networks: A Challenging Endeavor


Wireless Mesh Networks allow for the self-organizing formation and organic growth of wireless networks. Possible usage scenarios include public community networks, but also provider-operated wireless backbone networks. As a result, mesh networks cater to the vision of a wireless Internet. It is foreseen that such mesh networks are going to change the communication landscape in the domain of wireless networks; the impact might be as high as the impact of the Peer-to-Peer paradigm on the Internet.
However, one crucial success factor is still missing: Quality of Service support. In contrast to wire-line networks, the wireless medium is typically a shared medium. Moreover, in wireless (multihop) networks it is not feasible to address the QoS challenge with the brute-force overprovisioning approach employed in the wire-line domain. As a result, wireless mesh networks are far from adequately supporting multimedia applications such as gaming or voice/video-conversation.
In this talk, we discuss the introduction of QoS mechanisms into the MeSH mode of IEEE 802.16. In particular we discuss compatibility issues with the Point-to-Multipoint mode of 802.16 and show that cross-layer optimization is necessary to achieve the desired performance. Finally, we discuss selected avenues of research that open up on top of the proposed QoS mechanisms.


Ralf Since early 1996, Dr. Ralf Steinmetz has been a professor at the dept. of Electrical Engineering and Information Technology as well as at the dept. Computer Science of the Darmstadt University of Technology, Germany. There he is in charge of a chair position as managing director of the "Multimedia Communications Lab". From late 1996 until late 2001 he directed the Fraunhofer (former GMD) Integrated Publications and Information Institute IPSI. In 1999 he founded the Hessian Telemedia Technology Competence Center (httc e.V.). On whose board he has since served as chair.

His research interests cover networked multimedia issues with the vision of "seamless multimedia communications"; i.e. network dependability and security (e.g. gateways, firewalls), quality of service (e.g. network engineering), content distribution networks (e.g. streaming), context aware communications (e.g. peer-to-peer mechanisms), media semantics (e.g. ontology enrichment, metadata). At Darmstadt he relates these research issues often very closely to mobility, Internet telephony and telemedia learning.

He has been the editor and co-author of a multimedia course, which reflects the major issues of the first (updated in several versions) in-depth technical book on multimedia technology. He has worked as an editor of various IEEE, ACM and other journals. He has served as chair, vice-chair and member of numerous program and steering committees of communications and multimedia workshops and conferences. He is a member of the GI and VDE-ITG. He was awarded as ICCC Governor, the honour of Fellow of both, the IEEE and the ACM. In 2005 he became member of the technology advisory board of the “Hessen Agentur” and he was appointed as the advisor for information und communications technology by the Hessian government.