This paper proposes easily applicable distributed reputation-based policies to motivate users of a wireless community to share their Internet connection in a p2p fashion. The goal is the provision of free and good quality Internet access anytime and anywhere inside the community. We study general systems of users with different contribution and consumption profiles and show via an extensive simulation study that when our reputation-based allocation scheme is applied, mobile users enjoy a QoS Internet connection from their community in proportion to their cooperation level; the more greedy for community resources users are, the more contributive they should be to satisfy their needs.

In this paper, we study p2p systems, where peers have to share their available resources between their own and other peers' needs. One such example is a system of peers who use their capacity-limited access links both for their upstream and downstream connections. In the selfish approach, each peer would like to exploit the full capacity of his access link only for his downloads. However, if all peers acted selfishly, the system would collapse. In order to motivate peers to cooperate, we propose a distributed reputation-based system according to which peers earn reputation analogous to their contributions. In this way, each peer has to trade off the capacity he will dedicate for uploading in order to increase his reputation and therefore his revenue and the capacity he will dedicate for his downloads. All peers act rationally, trying to maximize their utility. Our proposed policies lead rational peers to cooperation while promoting fairness, as peers receive resources in proportion to their contributions. Our policies outperform existing work in this area in which the slowest link becomes the bottleneck of a heterogeneous system of different link capacity peers. On the contrary, no such bottleneck appears when our policies are used, improving the performance of the system. Finally, we apply our reputation-based approach in a BitTorrent-like file sharing system and we highlight the potential performance gains.