Collaborative & Cognitive Networking and Open Spectrum by Dr. Q Zhang Hong Kong University of Science and Technology Seminar Notice Date & Time : 1 November 2005, 11:45 am Location : Rm. 603, Chow Yei Ching Bldg Abstract : We have witnessed an unprecedented explosion in wireless networking technologies, including WiFi, networking WiFi, WiMax, Bluetooth, UWB, 3G, Software Defined Radio (SDR), etc. These technologies will co-exist in the future to form a WiMax, technologies comulti-radio wireless environment providing different service abilities to user applications. With the proliferation of multiwireless-enabled devices, and especially multi-radio/multi-band enabled devices, much attention has been paid to the wirelessmulti- radio/multidesire of ensuring “always best connected” networking. There are several key challenges. Due to the shared nature of connected” wireless media, contention from neighboring devices causes interference, which in turn results in significant system interference, performance degradation. To eliminate interference between different wireless technologies, current spectrum allocation different policies allocate a fixed spectrum slice to each wireless technology or service, which results in poor radio resource technology utilization. Meanwhile, controls in different layers of wireless networks, such as access model selection, power adjustment, channel/spectrum assignment, rate adaptation, scheduling, routing selection, etc. have mutual impact, which scheduling, makes radio resource management an extremely tough issue. While it shows promise, research and development of open spectrum and multi-radio networking is one of the hottest subjects in this field and is still in its infancy. Through studying multiand the unique characteristics of multi-radio wireless networks, collaborative and cognitive networking (CCN) is proposed multito make the devices cognitive to the environment and adapt to the best performance by device collaboration. After the introducing the scope of CCN, I will present two concrete technologes, i.e., SoftMAC and JCAR. To address the VoIP technologes, delivery over wireless mesh networks, Layer 2.5 SoftMAC that resides between the 802.11 MAC layer and IP layer is proposed to coordinate the real-time and best-effort packet transmission among neighboring nodes in a wireless mesh realbestnetwork. Distributed admission control, rate control, and non-preemptive priority queueing is introduced to regulate the noncontention in the mesh networks. Multiple orthogonal channels available in the wireless networks provide the feasibility available for interference mitigation among nearby access. With many mobile devices being equipped with more than one radio, mobile especially the heterogeneous ones, these devices will construct a Multi-radio Multi-channel Multi-hop Wireless Network MultiMultiMulti(M3WN). To effectively mitigate interference in M3WN, propose a novel software solution, called Layer 2.5 JCAR (joint channel assignment and routing), which resides between the MAC layer and routing layer. JCAR jointly coordinates the layer channel selection on each wireless interface and route selection among interfaces based on the traffic information measured and exchanged among two-hop neighbor nodes. twoBiography : Dr. Zhang (M’00, SM’04) received the B.S., M.S., and Ph.D. degrees from Wuhan University, China, in (M’ SM’ University, 1994, 1996, and 1999, respectively, all in computer science. Dr. Zhang joined Hong Kong University of Science and Technology in Sept. 2005 as an Associate Professor. Before that, she was in Microsoft Research, Asia, Beijing, China, from July 1999, where she was the research manager of the Wireless and Networking Group. Dr. Zhang has published Wireless more than 100 refereed papers in international leading journals and key conferences in the areas of wireless/Internet multimedia networking, wireless communications and networking, and overlay networking. She is the inventor of about 30 and pending International patents. Her current research interests are in the areas of wireless communications, IP networking, are multimedia, P2P overlay, and wireless security. She also participated many activities in the IETF ROHC (Robust Header participated Compression) WG group for TCP/IP header compression. Dr. Zhang is the Associate Editor for IEEE Transactions on is Vehicular Technologies and IEEE Transactions on Wireless Communications. She is now also serving as Guest Editor for Communications. special issue on wireless video in IEEE wireless Communication Magazine. Dr. Zhang has received TR 100 (MIT Magazine. Technology Review) world’s top young innovator award. She also received the Best Asia Pacific (AP) Young Researcher world’ Pacific Award elected by IEEE Communication Society in year 2004. She received the Best Paper Award in Multimedia received Technical Committee (MMTC) of IEEE Communication Society. Dr. Zhang is chair of QoSIG of the Multimedia Zhang Communication Technical Committee of the IEEE Communications Society. She is also a member of the Visual Signal Society. Processing and Communication Technical Committee and the Multimedia System and Application Technical Committee Multimedia of the IEEE Circuits and Systems Society.