CSMA-Based MAC Protocol For Cognitive Radio Networks

Cognitive radios (CR) technology enables wireless devices to dynamically switch between channels in a wide range of frequency bands and utilize unused parts of licensed and unlicensed frequency bands. The CR-enabled devices can either form a stand-alone multi-hop wireless network or form a multi-hop wireless backbone network that can connect different types of devices together. In a multi-hop wireless network composed of CR-enabled devices the number and the set of available channels vary from one node to another. This is in contrast to the existing multi-hop wireless mesh networks where all the nodes have the same set of channels available. In this paper we present a CSMA-based MAC protocol for CR-based multihop network. This protocol is based on the channel segregation technique proposed for cellular networks. Simulation results indicate that the protocol incurs low latency and achieves reasonable throughput.