Toward modeling the long-tail for a P2P community streaming system in DSL networks

An increasingly common feature of a Set Top Box (STB) is that of a Personal/Digital Video Recorder (PVR), which enables subscribers to record broadcasted content to be viewed at a later time--time-shifting. Currently, subscribers have the limited choice of watching time-shifted shows either from their own PVRs or from a centralized VoD server that makes available only the popular shows for time shifted viewing. Our CommunityPVR-a new system that forms a peer-to-peer network among the STBs and streams recorded content among peer STBs-makes available less popular titles to niche audiences (the long tail effect) of a community without incurring addtional cost to service providers for servers, bandwidth, and storage. In this paper, we present an analytical model to investigate how far along the tail of the popularity curve can be covered by CommunityPVR. Using TV shows ranked by Nielsen Media Research and VoD shows from China Telecom, our model provides a framework to determine the number of copies of broadcast/VoD content recorded by a community and the probability that CommunityPVR is able to deliver an on-demand stream of a given show over a DSL network. For example, CommunityPVR can stream near DVD quality video of the top ranked 5000 shows with 100% probability to a community of 100K. Unlike a centralized VoD solution, CommunityPVR has the potential to deliver both popular and long tail content on demand to a service provider's community in a cost-effective manner.