Combination of intra-flow network coding and opportunistic routing: reliable communications over wireless mesh networks

Opportunistic routing has recently appeared as a technique aimed to increase the performance of wireless mesh networks, by taking advantage of the broadcast nature of the wireless medium. Despite the remarkable attention the research community has paid to it, there are still some issues that need to be addressed; one of the most relevant ones is the unnecessary forwarding of the same packet by a number of nodes. Since Random Linear Coding (RLC) mechanisms randomly mix packets before forwarding them, they can be exploited to avoid (or at least to minimize) the aforementioned problem. In a previous work we introduced a flexible Network Coding (NC) entity that we integrated within the ns-3 framework. We extend herewith its functionalities, by integrating an opportunistic routing module that enables it to be used over random topologies. In addition, we assess the performance of using different external algebraical libraries to carry out the coding/recoding/decoding operations (i.e. matrix inverse and rank calculation).