Performance of Wireless Sensor and Actuator Networks (WSANs) for Real-Time, Fault-Tolerant and Energy-Efficient Transmission using Kautz Graph

Wireless sensor and actuator networks (WSANs) are composed of the sensors and the actuators to perform distributed sensing and the actuating tasks. Most WSAN applications (e.g., fire detection) demand that actuators rapidly respond to observed events. Therefore, real-time (i.e., fast) and fault-tolerant transmission and energy efficiency is a critical requirement in WSAN's to enable sensed data to reach actuators reliably and quickly. We then propose a Kautz-based REal-time, Fault tolerant and EneRgy-efficient WSAN (REFER). REFER embeds Kautz graphs into the physical topology of a WSAN for real-time communication and connects the Kautz graphs using distributed hash table (DHT) for high scalability. We also theoretically study routing paths in the Kautz graph, based on which we develop an efficient fault-tolerant routing protocol. It enables the relay node to quickly and efficiently identify the next shortest path from itself to the destination based only on node IDs upon routing failure, rather than relying on retransmission from the source.