Mitigating the Asymmetric Interests Among Peers in Peer-to-Peer Video-on-Demand Systems

In recent years, Peer-to-Peer (P2P) multimedia streaming has become an alternative to cable/satellite TV services. Many P2P streaming applications further provide users with DVD-like operations: play, pause, chapter selection, fast forward, and rewind. Such a real-time interactive multimedia streaming system is commonly referred to as P2P Video-on-Demand (VoD), and poses a unique challenge in providing smooth playback and seamless interaction over the Internet. In a typical P2P VoD system, a peer may play an arbitrary video segment at any time, which leads to asymmetric interests among peers. On one hand, the asymmetric interests reduce the incentives for peers to cooperate with each other. On the other hand, the asymmetric interests create more opportunities for content sharing. In this paper, we propose Coded VoD, a new approach for P2P VoD streaming, that exploits the content sharing opportunities in P2P VoD to address the incentive issue. Our experimental results show that Coded VoD achieves a smoother playback and faster responses to DVD-like operations by utilizing a network-coding-based content prefetching mechanism.