Residual White Space Distribution based opportunistic multichannel access protocol for dynamic spectrum access networks

We propose a multichannel MAC protocol for cognitive radio enabled Secondary Users (SUs) called Residual White Space Distribution based Cognitive MAC protocol (RWS-CMAC). Channel access in RWS-CMAC is based on residual idle time distribution of the channels. RWS-CMAC assumes a common control channel, which is used by sender and receiver SU nodes to exchange control messages for data channel negotiation. The proposed protocol ensures that the probability of interference of SU transmission with Primary User (PU) on each data channel is less than a predefined threshold for the corresponding channel. We also show using simulations that RWS-CMAC protocol is fair to the SUs operating in the network with respect to the secondary goodput and the sensing overheads incurred by SUs.