Peer-assisted VoD prefetching in double auction markets

In peer-assisted video-on-demand (VoD) streaming systems, server bandwidth costs can be astronomical when the number of videos and peers scales up. Since peers are able to seek to an arbitrary point of playback in any video at any time, prefetching is often considered a desirable way to redistribute media content in the entire system so that less server bandwidth may be consumed. In this paper, we point out that the benefits of prefetching in peer-assisted VoD do not come without considerable upfront costs of bandwidth, and as such prefetching strategies should be carefully designed to remain beneficial, but practically carried out in a decentralized manner. We show how the challenge of minimizing server bandwidth is equivalent to maximizing the system-wide utility in the context of double auction markets, where each peer participates in a number of double auctions by bidding for and selling video segments. With simulations, we show that prefetching strategies based on such double auction markets are decentralized, and are effective in reducing the consumption of server bandwidth as well, as compared to existing alternative heuristics in the literature.