标题：Free riding analysis of peer-to-peer streaming systems
作者：Qin, Fenglin ;Ge, Liansheng ;Liu, Qi ;Liu, Ju
作者机构：[Qin, Fenglin ;Ge, Liansheng ;Liu, Qi ;Liu, Ju ] School of Information Science and Engineering, Shandong University, Jinan 250100, China
来源：Journal of Computational Information Systems
关键词：Analysis; Free riding; Media streaming; Peer-to-peer
摘要：Free riding in peer-to-peer (P2P) systems means a peer utilizing other peers' network resources without contribution. Recent measurement studies have identified that there exits serious free riding problem in current P2P streaming systems, but scarce work is focused on theoretical aspects of free riding. In this paper, we present a simple probability model to study the free riding problem in P2P streaming systems. We theoretically analyze the effect of free riding on system performance including efficiency, playback continuity and transmission latency, and we also explore the relationship between the effect of free riding with specific system parameters like server bandwidth, peer degree and buffer length. Through some numerical results, we provide a quantitative understanding of the effect of free riding and conclude that it is essential to introduce incentive mechanism in P2P streaming systems. Copyright © 2011 Binary Information Press.