Medium Access Control Signaling for Reliable Spectrum Agile Radios

We address the problem of collaborative sensing in cognitive radios. In a cognitive radio network, all the nodes may sense the spectrum simultaneously. They should then exchange their sensing results in order to improve the reliability of the detection. This exchange of information has to be done efficiently to improve on the bandwidth efficiency of the network. We propose a medium access control (MAC) signaling protocol and study its performance behavior. For the case of a single-band channel, we present a thorough analysis of the proposed protocol and use the results to pick the protocol parameters that minimizes the signaling time for a given probability of detection. Analysis of the proposed protocol for multiband channels is solved by introducing a matrix formulation of the proposed protocol that allows its evaluation numerically.