A New Policy for Path Selection in Dynamic Source Routing Protocol for Mobile Ad-Hoc Networks

In standard DSR protocol, nodes automatically discover and maintain the routes in the network by storing source routes, discovered dynamically on-demand. They maintain route caches that contain the source routes which the node is aware of. Entries are continually updated when new routes are learned and reorder the cached routes according to the traditional shortest path policy. The problem with this approach is that, while the source is still using the primary shortest route, the primary route might fail and the source would remain unaware of that its cache contains a recent/fresh route, which has the same number of hop count and to the same destination. Thus, we proposed a method to improve the performance of DSR protocol by increasing packet delivery ratio and reducing routing overhead by adopting a path selection mechanism. In this study, we present a new strategy for route selection in DSR protocol that uses the recent-short path as routing metric. It calls RSRS. Basically, RSRS depends on the construction time and the hop-count of the cached route for route selection. Since, it utilizes the recent -short path in the route cache as routing metric. The proposed method has been implemented in GloMoSim simulator and its performance compared to the conventional DSR protocol and we have reached more important and comparable simulation results. The simulation results confirmed that the SRSR method improved packet delivery ratio, reduction of routing overhead, number of dropped packets and number of failure links.