Token-based incentive mechanism for peer-to-peer video streaming networks

We consider the problem of live video streaming in peer-to-peer networks consisting of selfish peers aiming at maximizing peers' individual utilities. We use token as an internal currency to encourage peers to cooperate in video distribution. Peers gain tokens by accepting requests from other peers for uploading video chunks to them, and they spend tokens for sending requests to the other peers and downloading video chunks from them. To handle the heterogeneity in the bandwidth of peers, we assume the video is coded as multilayered and each layer has a different type of token. Peers can request for a different number of layers to have their best quality based on their available token pools. To address this problem, we first study the peers' optimal strategies using the formalism of repeated games, and then, we show that peers' optimal strategy for each layer is a threshold strategy based on the number of tokens held by the peer for that layer. Then, we show that the repeated game can be converted to a simple one-shot game. In this new game, we study the impact of other peers' strategy on peers' utilities and strategies. We show that the game has a Nash equilibrium.