Cognitive radio networks improve spectrum utilization by sharing licensed spectrum with cognitive radio devices. In cognitive radio ad hoc networks the routing protocol is one of the most challenging tasks due to the changes in frequency spectrum and the interrupted connectivity caused by the primary user activity. In this paper, a multipath activity based routing protocol for cognitive radio network (MACNRP) is proposed. The protocol utilizes channel availability and creates multiple node-disjoint routes between the source and destination nodes. The proposed protocol is compared with D2CARP and FTCRP protocols. The performance evaluation is conducted through mathematical analysis and using OPNET simulation. The performance of the proposed protocol achieves an increase in network throughput; besides it decreases the probability of route failure due to node mobility and primary user activity. We have found that the MACNRP scheme results in 50% to 75% reduction in blocking probability and 33% to 78% improvement in network throughput, with a reasonable additional routing overhead and average packet delay. Due to the successful reduction of collision between primary users and cognitive users, the MACNRP scheme results in decreasing the path failure rate by 50% to 87%.
Multipath Activity Based Routing Protocol for Mobile Cognitive Radio Ad Hoc Networks