Date Added: Dec 2010
A wireless sensor network consists of a large number of such sensor nodes which are densely deployed in wide area. The technological improvement has made these low-power devices very cost effective. Sensor nodes are able to gather information about data processing, and communication. Information gathering is done by actual sensors, such as measuring the temperature, air pollution, pressure, etc. Some supporting functionalities such as power supplies, are required to build a complete sensor node. A sensor node is containing multiple sensors, radio and a processor. Therefore, multiple sensing units of a sensor node may be active at some particular time.