Techniques for peer-to-peer content distribution over mobile ad hoc networks

UnrestrictedThe mobile ad-hoc network (MANET) is emerging as a new paradigm of wireless communication in both civilian and military applications. Recently, efforts have been made to migrate peer-to-peer (P2P) applications from the wired Internet to the MANET system, which are expected to be the major impetus to MANET commercialization. Several fundamental technologies that facilitate the deployment of P2P content distribution systems over MANET are investigated. In particular, we have focused on efficient P2P content discovery and privacy protection in P2P file sharing.; First, a Bloom filter (BF)-based probabilistic routing (VABF) is proposed to improve query efficiency. The VABF protocol constructs its routing tables using Bloom filters in a distributed manner without the knowledge of the global network. Each node forwards P2P queries to its closest object holders by the shortest path. Simulation results show that VABF outperforms several popular unstructured P2P search algorithms in terms of the query success rate and the route strength.; Second, the performance of several unstructured P2P content discovery techniques over MANETs is analyzed. They include: query flooding, expanding ring search, random walk and BF-based probabilistic routing. The chosen performance metrics are the query success rate, the route stretch and the search cost. Mathematic analysis is conducted to predict their behavior in static networks. Besides, the overhead introduced by the BF-based probabilistic routing is modeled using a M/G/infinity queue. Finally, extensive computer simulation is performed to validate our analytical results in a static environment and shed light on the behavior of these schemes in a mobile environment.; Third, the MANET Anonymous Peer-to-peer Communication Protocol (MAPCP) is proposed for privacy protection. MAPCP uses broadcasts with probabilistic flooding control to establish multiple anonymous paths between communication peers. It requires no hop-by-hop encryption/decryption along anonymous paths and builds multiple paths to multiple peers within a single query phase without using an extra route discovery process. The analysis and simulations show that MAPCP always maintains a higher degree of anonymity than a MANET anonymous single-path routing protocol in a hostile environment