United nodes: cluster-based routing protocol for mobile cognitive radio networks

Advancement of cognitive radio (CR) technology can overcome the problems encountered from bandwidth and spectrum access limitations because of tremendous potential to improve the utilisation of the radio spectrum by efficiently reusing and sharing the licensed spectrum bands, as long as the interference power inflicted on the primary users of the band remains below a predefined threshold level. In mobile CR ad hoc networks, routing is one of the most important issues to be addressed and desires deep investigation. In this study, a distributed and efficient cluster-based spectrum and interference aware routing protocol is proposed. The protocol incorporates the spectrum availability cost and interference metrics into the routing algorithm to find better routes. A route preservation method is also implemented to repair the route when it is defective because of primary user activity. Extensive experimental evaluations are performed in the ns2 simulator. Results of the simulations illustrate that, the proposed algorithm can well fit into the mobile CR ad hoc networks and improve the network performance. The results indicate that the proposed protocol provides better adaptability to the environment than the existing ones. It also increases throughput and reduces data delivery latency in a number of realistic scenarios and outperforms recently proposed routing protocols for CR networks.