PALMS: A reliable and incentive-based P2P live media streaming system

Abstract

In recent years, the peer-to-peer (P2P) approach for media streaming has been studied extensively. In comparison with on-demand media streaming, P2P live media streaming faces a very stringent time constraint. To improve the performance metrics, such as startup delay, source-to-end delay, and playback continuity, we present PALMS - a P2P approach for live media streaming where a node employs gossip-based pull and push protocols to receive and forward media data among connected nodes.We present a simple heuristic mechanism for the pull protocol in the selection of media segments and peers. Besides the pull method, a push method is deployed to increase the streaming quality. We know that the presence of free-riders could degrade the delivered streaming quality. In PALMS, a simple score-based incentive mechanism, similar to BitTorrent's tit-for-tat incentive mechanism, is adopted to discourage the existence of free-riders. We conducted simulations and performance comparisons for PALMS. Experimental results demonstrate that PALMS can deliver better streaming quality and more resilience towards the heterogeneity of network bandwidths as compared to some of the existing protocols. © Springer 2008.