Improving the streaming capacity in P2P VoD systems with helpers

Peer-to-peer (P2P) video-on-demand (VoD) is a promising solution to provide video service to a large number of users. Streaming capacity in a P2P VoD system is defined as the maximal streaming rate that every user can receive. Due to the upload bottleneck, the streaming capacity in the P2P VoD system is limited. In this paper, we introduce helpers in the P2P VoD system and then optimize the helper resources to improve the streaming capacity. Specifically, we first optimize the helper assignment using a greedy algorithm. Then we develop a proximal distributed algorithm to maximize the streaming capacity by optimizing the link rates. Through simulations, we demonstrate that the P2P VoD system with optimized helpers can obtain a much higher streaming capacity compared to the P2P VoD system without any helper or the one with randomly assigned helpers.