Load balancing routing in cognitive radio ad hoc networks

Cognitive radio has recently emerged as a promising technology to promote the utilization efficiency of the existing radio spectrums allocation. In cognitive radio ad hoc networks (CRAHNs), the reachability of routes depends on both network topology and spectrum availability. To adapt to this feature, a cross-layer routing protocol is proposed, which is called load balancing ad hoc on demand distance vector (LB-AODV) protocol. Previous works paid little attention to the load condition of networks, which may lead to network congestion and degrade performance thereafter. To settle this problem, we use path queue length to indicate the load condition of different paths as the primary routing metric. In addition, a hop limitation is defined to limit average transmission delay. Detailed implementation steps of routing discovery and local adjustment are described as well. Simulation results demonstrate that compared with AODV, the proposed protocol provides better performance in both throughput and average packet delivery time in CRAHNs.