Squeezing the Most Out of Cognitive Radio: A Joint MAC/PHY Perspective

Cognitive radios provide means to improve the spectrum utilization by allowing opportunistic usage of allocated spectrum today if they are not utilized by the primaries. We first outline that there are two types of cognitive radios (S.N. Shankar et al., 2005), namely, static and dynamic cognitive radio. Then we explain the role of physical (PHY) and medium access control (MAC) layer of the cognitive radio and outlines the interaction to perform optimal operation. We model this total interaction by means of a queueing system and analyze the performance. It was found that dynamic cognitive nodes exhibit higher statistical multiplexing gain and lower delay compared to static cognitive radio network.