A QoS MAC Protocol for Cognitive PMP Networks with Rapid Changes of Spectrum Opportunities

This paper proposes a media access control (MAC) protocol with several efficient modules for cognitive point to multi-point (PMP) networks with rapid changes of spectrum opportunities. By modeling the status of each channel as a Markov process in the spectrum allocation module, we shall sense only a small set of possible channels while making efficient use of the spectrum and maintaining the frequency synchronization of all the cognitive users. And the admission control module, the rate control module and the resource allocation module guarantee the quality of service (QoS) requirements of different kinds of admitted connections on all the downlinks and uplinks by greedy algorithm and convex optimization. And our protocol also minimizes the total energy cost in the network. The simulation results show that our algorithm can make efficient use of the spectrum and the QoS requirements of all the connections are guaranteed.