Carpooling in Mobile Ad Hoc Networks: the Case of Multiple-Target Route Discovery

Carpooling is an efficient transportation option in real life because it reduces traffic and cost. We apply this idea to MANETs and propose multiple-target route discovery (MTRD) for on-demand routing protocols. MTRD aggregates multiple route requests into one RREQ message and discovers multiple targets simultaneously. When a node has to find a route to a destination, instead of immediately injecting a new RREQ message into the network, the node tries to discover a route by attaching its request to in-transit RREQ packets that it relays for other nodes. MTRD improves routing performance by reducing the number of regular route discoveries. The results of an extensive simulation study show that MTRD improves the routing performance significantly. Moreover, several important properties of MTRD are analyzed.