ABSTRACT
Wireless sensor networks that are capable of observing the environment, processing data, and making decisions based on these observations have recently attracted considerable attention.A These networks are important for a number of applications, such as coordinated target detection and localization, surveillance, and environmental monitoring. Breakthroughs in miniaturization, hardware design techniques, and system software, such as advances in microelectromechanical systems (MEMS), have made it possible to design a single wireless sensor node as a stand-alone system small in size and low in cost yet with full sensing and communication functionalities.B
A sensor node integrates hardware and software for sensing, data processing, and communication; the basic structure of a node is shown in Figure 29.1. Wireless sensor nodes are deployed in large numbers and organized in an ad hoc manner,C where nodes collect and exchange data about the environment and higher-level decisions can be made based on the integrated sensor data to achieve the required goal. Target tracking highlights the enormous potential of wireless sensor networks, especially in cases such as enemy intrusion detection in combat scenarios. Some practical examples of sensor networksD include AWAIRS at UCLA/RSC,1 Smart Dust at UC Berkeley,24 USC-ISI network,16 SensIT systems/networks,12 the ARL Advanced Sensor Program,47 and the DARPA Emergent Surveillance Plexus (ESP).48
