Impact of network coding on delay and throughput in practical wireless chain topologies

In this paper, we present results from a practical evaluation of network coding in a setup consisting of eight nodes deployed in a chain topology. With the tradition pure relaying, delay increases dramatically as the network gets congested, and here network coding helps to moderate this increase in delay, as well improving throughput. The practical evaluation shows that network coding provides up to a five-fold decrease in delay, while retaining the expected gain in throughput. To address an unecessary delay when using network coding in low-load scenarios, we propose and evaluate a scheme for adaptive buffering. With this, we show that the benefits from pure relaying can be combined with the improved performance from network coding. The software used to apply network coding and evaluate this in a practical network is made publicly available for further research and tests.