Optimizing Substream Scheduling for Peer-to-Peer Live Streaming

Abstract

Abstract—In peer-to-peer (P2P) live streaming using unstructured mesh, packet scheduling is an important factor on overall playback delay. The hybrid pull-push approach has been recently proposed to reduce delay compared to classical pulling method. In this approach, video are divided into substreams and packets are pushed with low delay. There has been little work addressing the scheduling problem on substream assignment. In this paper, we study the scheduling problem on assigning substreams to minimize packet delay. Given heterogeneous contents, delays and bandwidths of parents, we formulate the Substream Assignment (SA) problem to assign substreams to parents with minimum delay. The SA problem can be optimally solved in polynomial time by transforming it into a Max-Weighted Bipartite Matching problem. Simulation results show that our distributed algorithm achieves substantially lower delay as compared with traditional pull and current hybrid pull-push approaches based on greedy algorithm. I.