Improvement for AODV Based on Backup Path Strategy

Wireless links are often asymmetric due to the heterogeneity in transmission power of devices, the limitation of node energy, different antenna gain among nodes and non-uniform environmental noise. Nevertheless, most of the routing algorithms for ad hoc networks assume that all wireless links are bidirectional, such algorithms are not able to react to or exploit the full connectivity of the network. In this paper, an improvement for AODV based on Backup Path strategy (AODV-BP) is proposed, which computes routing path with backup routing table and Backtrack Route Reply mechanism when subjected to unidirectional links. Performance results using ns-2 simulations, under varying number of unidirectional links, show that AODV-BP performs well in scenarios where exist more unidirectional links when compared to basic AODV and AODV-Blacklist schemes.