MOVi+: Opportunity extension for mobile peer-to-peer video on demand

In a WiFi network with mobile nodes, it is quite a challenging task to provide P2P (peer-to-peer) VoD (video-on-demand) service while maintaining high aggregated throughput of network. MOVi (mobile opportunistic video-on-demand) is an early trial for mobile P2P VoD service where a centralized coordinator schedules segment-based transmissions (i.e., segment scheduling) for mobile nodes based on the opportunity, which reflects the pairing chances among nodes. Since MOVi scheduling depends on this fluctuating-over-time opportunity, mobile nodes may not play the video contents smoothly in case of temporal opportunity shortage. To mitigate this, in this paper, we propose to extend MOVi, MOVi+, by employing special peer nodes with segment caching capability and applying pre-diffusion-aware scheduling. With prototyped MOVi+ implementation, we validate the improved performance of MOVi+ in terms of segment-missing ratio, opportunity usage, segment distribution completion time, and the number of simultaneous playout mobile nodes with acceptable playout continuity (i.e., over 95%).