In this paper, optimal and sub-optimal routing protocols are proposed for cognitive radio networks. We first investigate optimal routing that consists in searching among all paths, the one that minimizes the end-to-end outage while verifying interference constraint to primary receiver. A sub-optimal one-hop routing is proposed where the best relay is selected in each hop. The last routing protocol consists in decomposing the network in many sub-networks composed of K hops. Then the best route is determined in each of these sub-networks so that the K hops-outage probability is minimized. The proposed K-hops routing allows a good compromise between complexity and performance. The performance of different routing protocols are evaluated through simulation results in terms of outage probability.
Interference Aware Routing Protocols for Underlay Cognitive Radio Networks