To Recode or Not to Recode: Optimizing RLNC Recoding and Performance Evaluation over a COTS Platform

Abstract:
Network Coding (NC) techniques have been shown to offer high robustness against losses, yielding relevant performance improvements. Although these advantages are also offered by rateless coding schemes, NC exhibits a greater potential, since intermediate nodes can also participate in the coding process, while packets traverse the network. However, the use of recoding at intermediate nodes exhibit some drawbacks, and it might not always lead to better performances. So far, there is not a closed answer to how, and when, to perform recoding. In this paper we develop an analytical model that is afterwards used to propose a scheme to optimize recoding operation at intermediate nodes. Both the model and the proposed solution are validated by means of extensive simulation experiments, but also over a real platform, comprising Raspberry-PI devices. The results show that an adequate configuration of the recoding operation might indeed yield notable performance gains, reducing the number of required transmissions for a reliable communication service.