Link performance based neighbor selection mechanism in BitTorrent for the wireless networks

BitTorrent is one of the most efficient file sharing application on the Internet today. However, the variability of link layer delay and the bandwidth distribution among different wireless devices are significant, thus the peer-to-peer applications like BitTorrent system may suffer the impact on performance in wireless networks. In this paper, we propose a link performance index λ that expresses the bandwidth and link delay of each peer, and then we propose a link performance based (LPB) neighbor selection mechanism, in which a node with a higher index value can more likely be chosen as neighbors and served by other peers in BitTorrent. The LPB mechanism can improve the bandwidth utilization and reduce the overall file download time. Simulation results show that our proposed LPB neighbor selection mechanism in BitTorrent can reduce the average download completion time up to 12% compared to the standard BitTorrent neighbor selection mechanism in wireless networks.