Wireless Sensor and Actuator Networks: Algorithms and Protocols for Scalable Coordination and Data Communication

Preface

Traditional and existing sensor and actuator networks use wired communications, whereas, wireless sensors provide radically new communication and networking paradigms, and myriad new applications. They have small size, low battery capacity, non-renewable power supply, small processing power, limited buffer capacity (thus routing tables, if used at all, must be small), a low-power radio, and lack unique identifiers. Sensors may measure distance, direction, speed, humidity, wind speed, soil makeup, temperature, chemicals, light, vibrations, motion, seismic data, acoustic data, strain, torque, load, pressure, and so on. These nodes are autonomous devices with integrated sensing, processing, and communication capabilities. Nodes in a sensor network are generally densely deployed. Thousands of sensors may be placed, mostly at random, either very close or inside a phenomenon to be studied. Once deployed, the sensors are expected to self-configure into an operational wireless network, and must work unattended. The limited energy budget at the individual sensor level implies that in order to ensure longevity, the transmission range of individual sensors needs to be restricted. In turn, this implies that wireless sensor networks must be multi-hop ones.

Current research and implementation efforts are mostly oriented toward a traditional scenario with stationary sensors and a single static sink that collects information from sensors where the sink is directly connected to the user ...