Prefetching Optimization in P2P VoD Applications

Most existing Peer-to-Peer (P2P) Video-on-Demand (VoD) systems have been designed and optimized for the sequential playback. In practice, users often want to seek to the positions they are interested in. Such frequent seeks raise a great challenge to the design of the prefetching scheme. In this paper, we propose an optimal prefetching scheme to minimize the expected seeking delay at every viewing position. The proposed prefetching scheme optimally determines which segments will be prefetched and cached, based on the segment access probability. Through extensive simulations, we demonstrate that the proposed prefetching scheme significantly reduces the seeking delay compared to the sequential prefetching scheme.