An effective dynamic spectrum access algorithm for multi-hop cognitive wireless networks

Spectrum utilization, as a current hot research topic, has been paid extensive attention to in cognitive wireless networks. However, due to the complexities and dynamic properties in wireless networks, how to enhance effectively the spectrum utilization is still the main challenge to encounter at present. In this paper, we propose an effective dynamic spectrum access algorithm to improve the spectrum utilization and reliable communication in the multi-hop cognitive wireless network. Considering the inherent nature of licensed users, we adopt the Pareto distribution to model their behaviors. Accordingly, cognitive users can accurately sense the white spectrum. Different from the general dynamic spectrum access, we exploit the acknowledge information to provide the reliable transportation of data packets in multi-hop cognitive wireless networks. Moreover, to achieve the high spectrum utilization, we use the graph theory to perform the reasonable channel allocations. The time and frequency division multiplexing technologies are adopted to propose our practical strategies of channel allocations and switches. Consequently, we can solve the problems of channels sensing, channel allocations, channel accesses and channel switches. Simulation results indicate that the algorithm proposed can effectively reduce the overhead of channel sensing and switching, and improve the spectrum utilization.