High quality P2P-Video-on-Demand with download bandwidth limitation

This paper investigates a VoD distribution architecture that exploits the increasing uplink and local storage capacities of customer equipment in a peer-to-peer (P2P) manner in order to offload the central video servers and the core network segment. We investigate an environment where (i) the peers´ upload speeds vary in time and (ii) on the subscriber´s downlink a strict bandwidth limit constrains the VoD delivery, and where (iii) this downlink limit is not significantly higher than the video´s own bit rate while (iv) the subscribers´ upload capacities are not cut down. In such an environment providing quality for a true VoD service requires carefully selected mechanisms. We show how the components (storage policy, uplink speed management) of a P2P-VoD system should be changed to be feasible under these conditions. The main component of the system determines the minimal required server speed as a function of the prebuffered content, the uploaders´ behaviours, and the given play back fault probability. Additionally, by using simulation we investigate the optimal downlink bandwidth limit for a subscriber population with different average upload speeds.