A Localization Routing Discovery Mechanism for Mobile Ad Hoc Networks

In mobile ad hoc networks, most reactive routing protocols often broadcast a route request by flooding for route discovery, and use only a time-to-live (TTL) field, the value of which is simply decreased by one at each node, to limit the broadcast radius. When the TTL reaches zero, the request packet is discarded before finding target. Such blind flooding will cause considerable routing overheads and result in serious redundancy, contention and collision which are known as broadcast storm problem. In this paper, we propose a novel Estimate-Hops Route Discovery (EHRD) scheme, which uses cached route history to adjust the TTL value automatically localizing the flood to a limited region of the network, and implement it in Dynamic Source Routing (DSR) protocol. Simulation results show that DSR with this mechanism can offer better efficiency than basic flooding approach.