An algorithm for cooperative data exchange with cost criterion

We consider the problem of minimizing the cost of cooperative data exchange between a group of wireless clients. In this problem, a group of clients needs to exchange a set of packets over a shared lossless broadcast channel. Each client initially holds a subset of packets and needs to obtain the packets held by other clients. At each round, one of the clients can broadcast its packets or a combination thereof over the channel. Each client is associated with a certain transmission cost that captures its ability to transmit packets. Such cost can depend on various factors, e.g., available battery life. In this paper, we present an efficient randomized algorithm that ensures that all clients receive all packets and minimizes the total transmission cost. We prove the optimality of the algorithm and perform simulation studies to estimate the advantage achievable by using the network coding technique.