Efficient on-demand routing using source-tracing in wireless networks

With on-demand routing, a router maintains routing information for only those destinations that need to be reached by the router. The approaches used to date to eliminate long-term or permanent loops in on-demand routing consist of obtaining complete routes to destinations dynamically, or obtaining only the next hops to destinations and validating the information using sequence numbers or internodal synchronization. We present a new approach to on-demand routing, which we call the DST (dynamic source tree) protocol. To eliminate looping, routers in DST communicate paths to destinations; however, only incremental updates to such paths are communicated by specifying the second-to-last hop and distance to each node in the subpath to the destination that must be updated. Simulations experiments are used to show that, in terms of control packet overhead, DST outperforms substantially the Dynamic Source Routing (DSR) protocol which is arguably one of the most efficient on-demand routing approaches to date, while achieving similar performance in terms of the average delay and throughput of data packets.