A Packet Scheduling Mechanism for Wireless Peer-to-Peer Content Distribution

This thesis studies the problem of content distribution in wireless peer-to-peer networks with selfish nodes. In this problem a group of wireless nodes need to exchange a set of files over a lossless broadcast channel. Each node aims to maximize its own download rate and minimize its upload rate. We propose a distributed protocol that provides incentives for selfish nodes to participate in the content exchange. Our protocol does not require any exchange of money and reputation and hence can be easily implemented without additional infrastructure.

Then, we will analyze the performance of our protocol by focusing on the import-ant case in which the system contains two files that need to be distributed. We derive a closed-form expression of Nash Equilibrium and characterize the corresponding system performance in discrete time. Furthermore, we propose a distributed mechanism where the strategy of each node is only based on the observed history of the system and not on the private information of other nodes.

We also study the performance characteristics of the systems that employ network coding to facilitate data exchange. We show that, due to the free rider problem network coding does not necessary improve the performance of the system and, in some cases, may lead to worse system performance. We propose a novel approach to this problem based on random coding. The performance of the network coding algorithms is validated by performing extensive simulation study.