SDN-TSCH: Enabling Software Defined Networking for Scheduled Wireless Networks with Traffic Isolation

The Industrial Internet of Things (IIoT) applications need to rely on a wireless infrastructure able to provide low end-to-end latency, and high reliability. Software-Defined Networking (SDN) is promising to make the network more agile, pushing the decision process to a controller. However, radio links are unstable while the controller needs to construct an accurate view of the network to schedule the transmissions efficiently. We propose here SDN-TSCH to separate the data and control planes for a scheduled network. We construct a reliable control plane, maintaining a collision-free path to and from the controller. Besides, SDN-TSCH guarantees flow isolation: each flow can reserve dedicated resources so that end-to-end reliability and latency constraints can be respected per flow. Finally, we also dedicate resources for best-effort traffic, to accommodate various applications. Our Cooja simulations highlight the flow isolation characteristics of SDN-TSCH: we provide very high reliability even in presence of best-effort traffic.