Improving decoding efficiency of opportunistic network coding via efficient data caching

Existing network coding architectures such as COPE in wireless networks depend on opportunistic listening to improve network throughput. Data cache management for the purpose of decoding to enhance the performance gain of network coding has not been deeply investigated. In this paper, we present a general model to address this problem, aiming at improving decoding efficiency of network coding and thus exploiting network throughput gain. We formulate the caching policy design as an optimization problem for maximizing caching decoding efficiency. Based on the model, we propose a distributed network coding caching policy(NCP) where each node independently manages the cache to maximize decoding efficiency. We theoretically analyze the performance improvement of NCP over COPE. We also use simulation experiments based on ns2 to validate our analytical model and verify the performance gain.