Wireless Sensor and Actuator Network (WSAN) monitors, senses and collects object information through sensor nodes in each region, and transfers it to the actuator node in an autonomous multi-hop manner1. Based on the monitoring signal collected, the actuator node decides and implements the relevant actions in order to achieve dynamic interaction between sensor nodes, the external environment and actuator nodes. There are many types of sensors, and the most common ones are physical sensors, chemical sensors, biological sensors, etc. (Table 1).

1 郎為民,資料通信,第3期,2011年。

Table 1: Examples of common sensors

Wireless sensor-actuator networks have a wide range of applications, and currently are used in: environmental monitoring and protection, healthcare, military, target tracking, etc. (Figure 1).

Figure 1: Applications of wireless sensor actuator networks

In everyday life, wireless sensor-actuator networks have a lot of practical applications, such as, home or building automation and control, lighting, air conditioning, security, access control and so on. Wireless sensor-actuator networks allow the automatic sensing of indoor and outdoor brightness, and the subsequent decision to whether to turn on the lighting to automatically adjust the brightness. Through sensing states, such as, the temperature and the humidity in the environment, wireless sensor-actuator networks can automatically adjust the temperature of the air conditioning, providing a convenient, comfortable and environmentally-friendly smart home solution.