Dynamic Route Shortening and Route Repairing Mechanism for Mobile Ad Hoc Networks

Abstract

Problem statement: Ad hoc Networks are wireless networks without any fixed infrastructure. The network topology changes frequently and unpredictably due to the random movement of the nodes. The Ad Hoc on Demand Distant Vector Routing (AODV) protocol works in a dynamic fashion, by establishing a route on demand and continues that route until it breaks. Due to the changing network topology of ad hoc networks, if other routes with less hop count become available, the network topology is not able to adapt until the route break occurs. Hence in the route shortening scheme is some redundant nodes in the active route is replaced with a node that is not on the active route. When there is any link failure between any two nodes, the alternative route with optimum route to be constructed and not sending RRER message to the source node to initiate the route discovery process again. Approach: This study proposes a new routing protocol called, Dynamic Route Shortening and Repairing Mechanism (DRSR). The route shortening is incorporated with route repairing mechanism, to improve the performance of the AODV. The route shortening scheme works by replacing some redundant nodes in the active route, with a node that is not on the active route. If there is a link failure between the two nodes, the route repairing mechanism repairs the route, by using the nodes that are close enough to the route to overhear the message. Whenever the links go down, the DRSR replaces the failed links with the optimum route that is adjacent to the main route and not sending and RRER message to the source node to initiate the route discovery process again. The alternative route construction process could be initiated at any time, not just when a route has failed. The dynamically constructed alternative route’s information is passed on to the upstream nodes, which then determine by themselves when to direct their packets to the ‘‘optimal’’ alternative route. Results: Our protocol performs better than the original (AODV), in terms of the packet delivery rate, average hops and packet loss. Conclusion: Our proposed routing protocol constructs the alternative route with the optimal route in the Dynamic Route Shortening scheme when there is a link failure between any two nodes.