A real-time communication framework for wireless sensor-actuator networks

Wireless sensor-actuator network (WSAN) comprises of a group of distributed sensors and actuators that communicate through wireless links. Sensors are small and static devices with limited power, computation, and communication capabilities responsible for observing the physical world. On the other hand, actuators are equipped with richer resources, able to move and perform appropriate actions. Sensors and actuators cooperate with each other: While sensors perform sensing, actuators make decisions and react to the environment with the right actions. WSAN can be applied in a wide range of applications, like environmental monitoring, battlefield surveillance, chemical attack detection, intrusion detection, space missions, etc. Since actuators perform actions in response to the sensed events, real-time communications and quick reaction are necessary. To provide effective applications by WSAN, two major problems remain: How to minimize the transmission delay from sensors to actuators, and how to improve the coordination among the actuators for fast reaction. To tackle these problems, we designed a real-time communication framework to support event detection, reporting, and actuator coordination. This paper explores the timely communication and coordination problems among the sensors and actuators. Moreover, we proposed two self-organized and distributed algorithms for event reporting and actuator coordination. Some preliminary results are presented to demonstrate the advantages of our approach.