Pro-Reactive Route Recovery with Automatic Route Shortening in Wireless Ad Hoc Networks

In this paper, we propose a relay recovery route maintenance protocol for ad hoc networks to combine the benefits of both proactive and reactive route recovery strategies and to minimize their drawbacks. In our proposal, one or more substitute routes usually become ready for the recovery of every link in a route before its break, while the route recovery process actually starts only when the upstream node of a link confirms the link break. Since this scheme does not broadcast any control packet, it can effectively recover a broken link without heavy control overhead traffic. Also, it helps reduce the time delay due to the recovery, since substitute routes are already available when the upstream node initiates the route recovery process. We further propose two automatic route shortening schemes to optimize the route during successful packet forwarding without causing extra control overhead. We have implemented our proposed schemes based on AODV and compared their performance with competitive schemes including original AODV. Simulation results demonstrate that our proposal definitely reduces the time delay and control overhead traffic in route repairing process, and that the route shortening schemes further leads to shorter time delay and average route length.