Advances in the miniaturization of microelectromechanical systems have led to battery-powered sensor nodes that have sensing, communication and p- cessingcapabilities. Thesesensornodescanbenetworkedinanadhocmanner to perform distributed sensing and information processing. Such ad hoc s- sor networks provide greater fault tolerance and sensing accuracy and are typically less expensive compared to the alternative of using only a few large isolated sensors. These networks can also be deployed in inhospitable terrains or in hostile environments to provide continuous monitoring and processing capabilities. A typical sensor networkapplication is inventorytracking in factorywa- houses. A single sensor node can be attached to each item in the warehouse. These sensor nodes can then be used for tracking the location of the items as they are moved within the warehouse. They can also provide information on the location of nearby items as well as the history of movement of various items. Once deployed, the sensor network needs very little human interv- tion and can function autonomously. Another typical application of sensor networks lies in military situations. Sensor nodes can be air-dropped behind enemy lines or in inhospitable terrain. These nodes can self-organize th- selves and provide unattended monitoring of the deployed area by gathering information about enemy defenses and equipment, movement of troops, and areas of troop concentration. They can then relay this information back to a friendly base station for further processing and decision making. Sensor nodes are typically characterizedby small form-factor,limited b- tery power, and a small amount of memory.
Krishnendu Chakrabarty is an Associate Professor of Electrical and Computer Engineering at Duke University. He has co-authored two books, edited a third book, and published over 150 papers in archival journals and refereed conference proceedings.
S. S. Iyengar (AAAS Fellow, IEEE Fellow, ACM Fellow) is the Roy Paul Daniels Professor of Computer Science and Chairman of the Department of Computer Science at Louisiana State University. He is the author/co-author of 13 books and he has published more than 280 papers in journals and refereed conference proceedings. He has given more than 50 plenary talks and invited lectures.He is the Editor-in-Chief of the International Journal of Distributed Sensor Networks (Taylor-Francis/CRC Press).
