Server Guaranteed Cap: An Incentive Mechanism for Maximizing Streaming Quality in Heterogeneous Overlays

We address the problem of maximizing the social welfare in a peer-to-peer streaming overlay given a fixed amount of server upload capacity. We show that peers’ selfish behavior leads to an equilibrium that is suboptimal in terms of social welfare, because selfish peers are interested in forming clusters and exchanging data among themselves. In order to increase the social welfare we propose a novel incentive mechanism, Server Guaranteed Cap (SGC ), that uses the server capacity as an incentive for high contributing peers to upload to low contributing ones. We prove that SGC is individually rational and incentive compatible. We also show that under very general conditions, there exists exactly one server capacity allocation that maximizes the social welfare under SGC, hence simple gradient based method can be used to find the optimal allocation.