Network Coding on Wireless Multipath for Tactile Internet with Latency and Resilience Requirements

Many envisioned applications for the Tactile Internet require latencies that cannot be achieved by current wireless networks. In this paper, we present a method to optimize the reliability of a live stream using multiple paths. Compared to other approaches, our method does not rely on feedback to achieve the reliability and thus does not add delay for retransmission attempts. We use the diversity of multiple paths to compensate for the loss of capacity in individual paths. By using an FEC code to generate redundant data the transmission is more robust against fluctuations in capacity of single paths. We present an optimization problem to find a rate allocation for the paths that minimizes the interruptions of the stream. The performance is evaluated in an emulated network based on real-world measurements. The evaluation shows that the theoretical values can be achieved with a small margin. The optimized allocation of rates to the paths increases the reliability by up to 12%. With coding the reliability can be increased by up to 20%, depending on the code rate.