A Path-Centric Channel Assignment Framework for Cognitive Radio Wireless Networks

Today’s static spectrum allocation policy results in a situation where the available spectrum is being exhausted while many licensed spectrum bands are under-utilized. To resolve the spectrum exhaustion problem, the cognitive radio wireless network, termed CogNet in this paper, has recently been proposed to enable unlicensed users to dynamically access the licensed spectrum bands that are unused in either temporal or spatial domain, through spectrum-agile cognitive radios. The CogNet plays the role of secondary user in this shared spectrum access framework, and the spectrum bands accessible by CogNets are inherently heterogeneous and dynamic. To establish the communication infrastructure for a CogNet, the cognitive radio of each CogNet node detects the accessible spectrum bands and chooses one as its operating frequency, a process termed channel assignment. In this paper we propose a graph-based path-centric channel assignment framework to model multi-hop ad hoc CogNets and perform channel assignment from a network perspective. Simulation results show that the path-centric channel assignment framework outperforms traditional link-centric approach.

Chien-Chung ShenEmail:

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Chunsheng Xin   received the Ph.D. degree in computer science from State University of New York at Buffalo in 2002. From 2000 to 2002, he was a Research Co-Op in Nokia Research Center, Boston. From 2002, he is an assistant professor in the Computer Science Department, Norfolk State University, Norfolk, Virginia. His research interests include optical networks, cognitive radio wireless networks, and performance evaluation and modeling. Liangping Ma   received his B.S. degree in Physics from Wuhan University, Hubei, China, in 1998, and his Ph.D. degree in Electrical Engineering from the University of Delaware, Newark, DE, in 2004. He was with the University of Delaware as a Postdoctoral Research Fellow. Since 2005, he has been with San Diego Research Center, Inc. (now part of Argon ST, Inc.), San Diego, CA, as a Research Staff Member. His research interests include medium access control (MAC), spectrum agile radios, and signal processing. Chien-Chung Shen   received his B.S. and M.S. degrees from National Chiao Tung University, Taiwan, and his Ph.D. degree from UCLA, all in computer science. He was a senior research scientist at Bellcore (now Telcordia) Applied Research working on control and management of broadband networks. He is now an associate professor in the Department of Computer and Information Sciences of the University of Delaware, and a recipient of NSF CAREER Award. His research interests include ad hoc and sensor networks, dynamic spectrum management, control and management of broadband networks, distributed object and peer-to-peer computing, and simulation. He is a member of both ACM and IEEE.