Optimal Cooperative Spectrum Aware Opportunistic Routing in Cognitive Radio Ad Hoc Networks

Opportunistic cognitive routing coupled with dual-stage collaborative spectrum sensing in multi-channel multi-hop cognitive radio ad hoc networks (CRAHNs) is investigated in this work. Due to the dynamics of available spectrum and complex radio environment in CRAHNs, an opportunistic cognitive routing protocol is proposed, that exploits a dual-stage collaborative spectrum sensing (DCSS) scheme to improve spectrum availability under the effects of Primary Users' activities. Solutions to select the optimal routing path were provided by adopting the proposed two routing metrics with routing access opportunity and routing transmission delay. The expressions in terms of the proposed two routing metrics are analytically derived and validated. Performance evaluation is conducted through simulations, and simulation results reveal that routing access opportunity and expected transmission delay are improved by using the proposed DCSS scheme, compared with those using the single cooperative spectrum sensing scheme and non-cooperation sensing scheme. In addition, it is observed that the number of next hop neighboring nodes, the number of available channels, and hop counts also affect the routing establishment and expected transmission delay.