Power Aware Virtual Path Routing Protocol for Cognitive Radio Ad Hoc Networks

Abstract

One of the difficult challenges in Cognitive Radio Ad Hoc Networks (CRAHNs) is the throughput maximization in an environment with uncertain availability of spectrum resources and spatial diversity. Opportunistic spectrum utilization can alleviate the degradation in throughput by employing dynamic routing algorithm and accomplishing Virtual Path Routing (VPR). The VPR aims at finding the most reliable path for multi-hop communication between Secondary Users (SUs) in the presence of Primary Users (PUs) and other interfering SUs. By joint routing and dynamic spectrum access with interference avoidance, VPR selects the path, which ensures optimal link throughput with minimum interference. In this chapter, two utility functions are proposed for cognitive networks routing. The first utility function incorporates probabilistic Signal-to-Interference Ratio (SIR), PU influence and channel switching time delay. The second proposed utility is based on minimizing power consumption to improve battery lifetime. The VPR performance is compared with other well known works in terms of throughput, Bit Error Rate (BER) and Packet Arrival Delay (PAD). The results suggest VPR provides better end-to-end throughput, BER and PAD by avoiding zones of PU presence and mitigating interference effects of neighboring SUs. It is observed that applying a power control scheme such as water-filling, the VPR shows improved throughput. The BER for VPR with water-filling is also reduced compared to the previously suggested scheme such as Gymkhana alongwith the efficient power consumption.