Proximity-based overlay routing for service discovery in mobile ad hoc networks

We propose a proximity-based overlay routing algorithm for accelerating the service discovery using the distributed hash table (DHT)-based peer-to-peer (P2P) overlay in mobile ad hoc networks (MANET). DHT systems are useful for resource restrained MANET devices due to the relatively low communication overhead. However, the overlay routing for service discovery is very inefficient, since overlay structure is independent of physical network topology. Our proximity-based overlay routing utilizes the wireless characteristics of MANETs. The physically closer node to destination is preferred to the logical neighbors, using information collected by 1-hop broadcast between a node and its physical neighbors. More enhancement is achieved by the shortcut generated from the service description duplication. In a detailed ns-2 simulation study, we show that the proposed scheme achieves approximately shortest physical path without additional communication overhead, and also find that it works well in the mobile environment.