Opportunistic Spectrum Access Protocol for Cognitive Radio Networks

In this paper, we consider the medium access control (MAC) protocol design for cognitive radio networks. An opportunistic spectrum access protocol named Slotted CR-ALOHA is proposed, and its performances in terms of normalized throughput and average packet delay are evaluated. Simulation results show that for various frame lengths and number of SUs, the optimal performance can be achieved at an appropriate spectrum sensing time, and there also exists a tradeoff between the achievable performance of secondary network and the protection effect on primary network.