ABSTRACT
A sensor network consists of a large number of sensor nodes that are densely deployed either inside or close to the phenomenon. In general, the positions of sensor nodes need not be engineered or predetermined. This allows for random deployment in inaccessible terrain or disaster relief operations. Sensor networks can be considered as a special type of ad hoc wireless networks, where sensor nodes are, in general, stationary. A unique feature of sensor networks is the cooperative effort of sensor nodes. Sensor nodes are usually fitted with onboard processors. Instead of sending the raw data to the nodes responsible for the fusion, they use their processing abilities to locally carry out simple computations and transmit only the required and partially processed data. A sensor system normally consists of a set of sensor nodes operating on limited energy and a base system without any energy constraint. Typically, the base station serves as the gathering point for the collected data (through fusion). The base station also broadcasts various control commands to sensor nodes.
