A Supply-and-Demand Model for On-Demand Streaming in Networked Virtual Environments

In a large scale networked virtual environment, users may request various multimedia data in streaming. Although adopting a peer-to-peer (P2P) architecture can make the transmission of on-demand streaming more efficient, most existing research assume that the peers have infinite buffer to cache the entire content and supply the data from there. In this paper, we consider the practical case in which the peers have limited buffer space to cache only a portion of the multimedia content. Due to limited buffer space, peers need effective chunk selection strategies to fetch and discard chunks. We propose a supply-and-demand strategy to estimate the usability of chunks. Peers then select the chunks with a higher usability to fetch and discard the chunks that are useless. Simulation results show that the supply-and-demand strategy selects the chunks accurately and enhances the continuity of playing the stream.