Using bandwidth sharing to fairly overcome channel asymmetry

We propose a peer-to-peer architecture designed to overcome asymmetries in upload/download speeds that are typical in end-user dialup, broadband and cellular wireless internet connections. Our approach allows users at remote locations to access information stored on their home computers at rates often exceeding their home connection’s upload capacity. The key to this approach is to share file data when communications are idle using random linear coding, so that, when needed, an end-user can download a file from several sources at a higher data rate than his home computer’s upload capacity. We prove that our proposed system is asymptotically fair, in that (even malicious) users are proportionally assigned idle bandwidth depending on how much bandwidth they contribute, and that there is a natural incentive to join and cooperate fairly in the system. In addition, our approach provides cryptographic security and geographic data robustness to the participating peers.