Joint routing and MAC for critical traffic in Industrial Wireless Sensor and Actuator Networks

This paper proposes Delay Bounded Routing (DBR) and a Priority-based Medium Access Control method (Priority-MAC), designed for routing critical traffic in Industrial Wireless Sensor and Actuator Networks (IWSAN). A notable trend in industrial automation in recent years is the replacement of wired communication with IWSAN. Exceeding the required delay bound for unpredictable and emergency traffic could lead to system instability, economic and material losses, system failure and, ultimately, a threat to human safety. Guaranteeing the timely delivery of the critical traffic and its prioritization over regular traffic (e.g. non-critical monitoring traffic) is a significant challenge. Therefore, we present the design, implementation and evaluation of DBR and PriorityMAC. DBR and PriorityMAC are implemented in TinyOS and evaluated on a testbed of Telosb motes. The experimental results indicate that our protocol achieves a significant improvement of the end-to-end delivery latency compared to the current industrial standards.