Path-Centric Channel Assignment in Cognitive Radio Wireless Networks

Today´s spectrum allocation framework grants a spectrum band to each wireless service for exclusive usage, resulting in the spectrum exhaustion problem. Nevertheless, many recent studies showed that a large number of spectrum bands are not used in most of time. To resolve spectrum exhaustion problem, the cognitive radio wireless networks, termed CogNets in this paper, were proposed in the literature, where unlicensed users are allowed to access licensed spectrum, provided that licensed users are not interfered. The CogNet nodes play the role of secondary user in this shared spectrum access framework, and thus the spectrum bands used 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 path-centric channel assignment algorithm for multi-hop ad hoc CogNets. Numerical results showed that the proposed algorithm can obtain very good performance.