A Modified Approach to Dynamic Source Routing in Mobile Ad-Hoc Networks

To ensure uninterrupted communication in a mobile ad-hoc network, ef- ficient route discovery is crucial when nodes move and/or fail. Hence, pro- tocols such as Dynamic Source Routing (DSR) precompute alternate routes before a node moves and/or fails. In this paper, we modify the way these alternate routes are maintained and used in DSR, and show that these modi- fications permit more efficient route discovery when nodes move and/or fail. Our simulation results show that maintenance of these alternate routes (with- out affecting the route cache size at each router) increases the packet delivery ratio without incurring any extra traffic overhead. We also show that our ap- proach enables us to provide QoS guarantees by ensuring that appropriate bandwidth will be available for a flow even when nodes move. Towards this end, we show how reservations can be made on the alternate routes while maximizing the bandwidth usage in situations where nodes do not move.