Abstract
The origins of networks of sensors can be traced back to the 1980s when DARPA initiated the distributed sensor networks program. However, recent advances in microprocessor fabrication have led to a dramatic reduction in both the physical size and power consumption of such devices. Battery and sensing technology, as well as communications hardware, have also followed a similar miniaturization trend. The aggregation of these advances has led to the development of networked, millimeter-scale sensing devices capable of complex processing tasks. Collectively these form a wireless sensor network (WSN), thus heralding a new era of ubiquitous sensing technology and applications. Large-scale deployments of these networks have been used in many diverse fields such as wildlife habitat monitoring (Mainwaring, Polastre, Szewczyk, Culler, & Anderson, 2003), traffic monitoring (Coleri, Cheung, & Varaiya,, 2004), and lighting control (Sandhu, Agogino, & Agogino, 2004).