Date Added: Jan 2012
In this paper, the authors consider two major factors that have significant impact on average download time, namely, the spatial heterogeneity of service capacities in different source peers and the temporal fluctuation in service capacity of a single source peer. They point out that the common approach of analyzing the average download time based on average service capacity is fundamentally flawed. They rigorously prove that both spatial heterogeneity and temporal correlations in service capacity increase the average download time in P2P networks and then analyze a simple, distributed algorithm to effectively remove these negative factors, thus minimizing the average download time. They show through analysis and simulations that it outperforms most of other algorithms currently used in practice under various network configurations.