Conflict-Aware Real-Time Routing for Industrial Wireless Sensor-Actuator Networks

As process industries start to adopt wireless sensoractuator networks (WSANs) for control applications, it is crucial to achieve real-time communication in this emerging class of networks. Routing has significant impacts on end-to-end communication delays in WSANs. However, despite considerable research on real-time transmission scheduling and delay analysis for such networks, real-time routing remains an open question for WSANs. This paper presents a conflict-ware real-time routing approach for WSANs. This approach leverage a key observation that conflicts among transmissions sharing a common field device contribute significantly to communication delays in industrial WSANs such as WirelessHART networks. By incorporating conflict delays in the routing decisions, conflict-aware real-time routing algorithms allow a WSAN to accommodate more realtime flows while meeting their deadlines. Evaluation based on simulations and experiments on a real WSANs testbed show conflict-aware real-time routing can lead to up to three-fold improvement in real-time capacity of WSANs.