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A Survey on Multichannel Access Methods in Wireless Networks
PhD Qualifying Examination Title: "A Survey on Multichannel Access Methods in Wireless Networks" by Miss Lu WANG Abstract: The fixed spectrum assignment policy limits the efficiency of today’s wireless spectrum usage. As the spectrum demand for unlicensed band is increasing in recent years, Dynamic Spectrum Access (DSA) in Cognitive Radio (CR) networks has been proposed to address the spectrum under-utilization problem. DSA allows unlicensed users to share licensed spectrum in space and time with little interference to licensed users. This idea is originally inspired by Medium Access Control (MAC) designs in traditional Multichannel wireless networks, which can reduce interference among users as well as improve the spectrum utilization by leveraging multiple concurrent transmissions in a set of frequency channels. Although DSA has improved spectrum usage efficiency by opportunistically exploiting the existing wireless spectrum, it shares the same methodology with Multichannel MAC protocol in coordinating spectrum access among multiple users. Thus their performances are both degraded due to several common issues such as Common Control Channel (CCC) Saturation. In order to better design DSA in CR networks and bring ideas from traditional wireless networks, we firstly review different Multichannel MAC protocols in ad-hoc networks by classifying them into four categories based on their operation principles. Then we analyze and compare each category with representative protocols. Finally we briefly discuss some design challenges when applying traditional Multichannel MAC protocols to DSA, and other newly raised ones resulting from changing and heterogeneous characteristics of CR networks. Date: Thursday, 31 March 2011 Time: 2:00pm - 4:00pm Venue: Room 4480 lifts 25/26 Committee Members: Prof. Mounir Hamdi (Supervisor) Dr. Jogesh Muppala (Chairperson) Dr. Lin Gu Prof. Qian Zhang **** ALL are Welcome ****