Cross-layer design of P2P file sharing over mobile ad hoc networks

Peer-to-peer file sharing over mobile ad hoc networks (MANET) has become a popular application due to the rapid growing number of mobile devices. However, the fact that mobile nodes in a MANET dynamically alter their locations and join/leave the P2P system has posted many challenges in designing a robust and scalable P2P system. Although, in the literature, flooding-based P2P approach has been shown to be robust in a highly dynamic network, it leads to poor efficiency in terms of bandwidth usage and scalability. A new design is required in which cross-layer designs and cognitive approaches could be applied such that it could interact with the requests of users and respond to dynamic change of network topology. In this paper, we propose an efficient and scalable P2P file sharing system over MANET based on Swarm Intelligence, referred to as P2PSI. By applying the cognitive behaviour of the real ant colonies, P2PSI owns the capability of adaptive learning of routing path and is able to cope with mobility problem without flooding. Moreover, P2PSI also adopts cross-layer design to reduce the redundant message overhead and query latency. Performance of P2PSI is evaluated and compared to two existing cross-layer design service discovery protocols through simulations. Our simulation results show that P2PSI achieves better performance in terms of control overhead and request success ratio.