Minimizing weighted sum finish time for one-to-many file transfer in peer-to-peer networks

This paper considers the problem of transfer ring a file from one source node to multiple receivers in a peer-to-peer (P2P) network. The objective is to minimize the weighted sum finish time (WSFT) for the one-to-many file transfer where peers have both uplink and downlink bandwidth constraints specified. The static scenario is a file-transfer scheme in which the constructed network topology and the network resource (link throughput) allocation remains static until all receivers finish downloading. This paper first shows that the static scenario can be optimized in polynomial time by convex optimization, and the associated optimal static WSFT can be achieved by linear network coding. This paper also proposes a static rateless-coding-based scheme which has almost-optimal empirical performance. The dynamic scenario is a file transfer scheme which can re-construct the network topology and re-allocate the network resource during the file transfer. This paper proposes a dynamic rateless-coding based scheme, which provides significantly smaller WSFT than the optimal static scheme does.