A new cross-layer unstructured P2P file sharing protocol over mobile ad hoc network

We consider the scenario of mobile ad hoc network (MANET) where users equipped with cell phones, PDAs and other handheld devices, communicate through low radio range technology. In this paper, we propose a new cross-layer unstructured peer-to-peer (P2P) file sharing protocol over MANET. We assume that all nodes, though not necessary for them all to be the members of P2P network, are cooperative in forwarding the data for others. In our proposed algorithm the connectivity among the peers in the overlay is maintained closer to the physically topology by efficiently using the expanding-ring-search algorithm during the joining and leaving process of a peer. The connectivity information among peers is used to send the P2P traffic only to the concerned node, avoiding extra traffic to other nodes. Taking the advantage of wireless broadcast, we propose multicasting mechanism to send at a node the keep-alive and file-lookup messages to neighbor peers further reducing the routing overhead in the network. Simulation results show that our approach performs better in comparison with ORION (the flooding-based approach).