A Routing Protocol for Cognitive Radio Ad Hoc Networks Giving Consideration to Future Channel Assignment

Cognitive radio technology can be used to solve the problems of limited available spectrum and inefficient spectrum usage by adaptively changing transmission parameters. By utilizing CR technology for dynamic and distributed multi-hop networks, cognitive radio ad hoc networks can efficiently utilize free wireless resources. However, the routing protocols for cognitive radio CSMA/CA ad hoc networks have not been discussed seriously. An efficient protocol considering primary user flows and channel assignment incurred network connectivity issue in the route selection is still missing. In this paper, we propose AODV-cog, a cognitive routing protocol for CSMA/CA ad hoc networks based on AODV. AODV-cog chooses a route by considering the effect on the primary users, available channel bandwidth and link reliability. AODV-cog also takes in account of future channel utilization which is important but overlooked by existing works. AODV-cog switches channels for secondary user flows when network congestion is occurred. We use computer simulations to show the advantage of AODV-cog over existing alternatives.