ROAR: A Multi-rate Opportunistic AODV Routing Protocol for Wireless Ad-Hoc Networks

In this paper, we outline a simple approach, called ROAR, that enables the Ad-Hoc On-Demand Distance Vector (AODV) routing protocol to strengthen its routes by recruiting neighbors of nodes on the least cost path as support nodes during the route construction process, and working closely with the medium access control (MAC) to employ an opportunistic forwarding scheme that takes advantage of the node diversity at each hop. We have implemented ROAR in the ns-2 simulator over the IEEE 802.11a physical layer. From our simulation studies conducted using various network topologies and realistic radio propagation model, we find that ROAR increases AODV’s packet delivery ratio and end-to-end throughput several orders of magnitude, in particular for hop count based routes. Therefore, ROAR provides a simple add-on that allows routing protocols to reap the benefits of diversity without relying on physical layer approaches.