Distributed control of coded networks

[摘要] (cont.) The second part of our work focuses on analysis of COPE, a distributed opportunistic network coding system for wireless mesh networks. Experiments have shown that COPE can improve network throughput significantly, but current theoretical analysis fails to fully explain this performance. We argue that the key factor that shapes COPE;;s performance curve is the interaction between COPE and the MAC protocol. We also propose a simple modification to COPE that can further increase the network throughput. Finally, we study network coding for content distribution in peer-to-peer networks. Such systems can improve the speed of downloads and the robustness of the systems. However, they are very vulnerable to Byzantine attacks, and we need to have a signature scheme that allows nodes to check the validity of a packet without decoding. In this work, we propose such a signature scheme for network coding. Our scheme makes use of the linearity property of the packets in a coded system, and allows nodes to check the integrity of the packets received easily. We show that the proposed scheme is secure, and its overhead is negligible for large files.

[发布机构] Massachusetts Institute of Technology