A Proactive Scheme Using Sub-path Extension to Enhance Performance of Preemptive Route Maintenance Scheme for AODV Routing

Abstract

Existing on-demand routing algorithms for mobile ad hoc networks such as DSR (dynamic source routing) and AODV (ad hoc on-demand distance vector) routing do not consider maintenance of established paths. So after a link failure is detected, the path discovery operation is triggered. This causes delay and jitter to packets delivered. To address this problem, the recovery action is triggered early in preemptive route maintenance by detecting that a link is likely to break soon and it finds an alternative path in advance. However, broadcasting RREQs (Route Requests) to find an alternate good path can degrade the performance of mobile ad hoc networks where topology changes frequently. [3] A new proactive scheme is proposed to enhance performance of preemptive route maintenance for AODV. In the proposed idea, nodes adjacent to destination generate GREPs (gratuitous replies) to build extended sub-paths to source and the generated GREPs are forwarded by the “greedy forwarding” strategy using knowledge of position information of neighbors and source. The simulation results prove that our idea is more efficient than PAODV (AODV with preemptive route maintenance) in terms of number of broken links, packet delivery fraction, and routing load.