A novel opportunistic spectrum aware routing for cognitive radio wireless mesh network

In this paper, we proposed a novel opportunistic spectrum aware routing in cognitive radio wireless mesh network (CRWMN) which allows the CR users effectively occupy the spectrum band depends on the spectrum availability and also perform dynamically channel switching for performance optimization. In a CRWMN, primary hidden node (PHN) and primary exposed node (PEN) problems influence the performance of secondary user (SU). The proposed routing scheme will generate three channel lists between two neighbouring SUs when they are intended to communicate to each other. Firstly, channel of common spectrum opportunity list (CSOL) to meet the minimum requirement and could be used for communication between the two SUs. Secondly, channel of basic list (BL) can be used for communication which can prevent the PEN and PHN problems. Lastly, channel of superior list (SL) can be used by the two neighbouring SUs to communicate and it is the best channel to be used for performance optimization. Hence, the proposed spectrum aware routing protocol will avoid the performance degradation due to the PHN and PEN problems, as well as sudden appearance of PU. Simulation results show that the proposed spectrum aware routing scheme is able to reduce the average end-to-end delay and also enhance the networks throughput.