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Opportunistic Periodic MAC Protocol for Cognitive Radio Networks

Cognitive radio networks enable opportunistic sharing of bandwidth/spectrum. In this paper, we propose a new Opportunistic Periodic MAC protocol (OP-MAC), a protocol that aims at improving the coexistence of licensed primary users and unlicensed secondary users in cognitive radio networks. Under OP-MAC, secondary users cooperate to periodically sense channels, report channel states and exchange control signals, in such a way that we can avoid the common control channel problem and the multi-channel hidden terminal problem. Analysis is provided for an ON/OFF channel scenario and is shown to be consistent with simulation results. With the requirement of only one transceiver per secondary user, OP-MAC is shown to provide higher capacity than a Random-MAC and a control-channel-based CO-MAC.