A sensor network consist of many spatially distributed sensors, which are used to monitor or detect phenomena at different locations such as temperature changes, pollutant levels, etc. Usually, each sensor is intended to be physically small and inexpensive, thus making it possible to produce and deploy them in large numbers. A sensor is equipped with a radio transceiver, a small microcontroller, and an energy source, usually a battery. In order to meet the objective of the sensors being small and low-cost, resources in terms of energy, memory, computational speed and bandwidth are severely constrained. The sensors use each other to transport data to a monitoring entity. Because each sensor has a limited energy supply, it is important that the sensors conserve their energy if the network should last for a long time.

Sensor network involves technologies from three relative areas: sensing, communication, and computation (hardware, software, algorithm).

Application

Sensor networks are applied in a wide variety of areas, such as environmental monitoring, video surveillance, traffic monitoring, air traffic control, industrial and manufacturing automation.

Brief History

The early sensor network was applied for military purpose, like the Sound Surveillance System(SOSUS)During the ColdWar. Modern research on sensor networks started around 1980 at the Defense Advanced Research Projects Agency (DARPA): Distributed Sensor Networks (DSN) program. Smaller computing chips, more capable sensors, wireless network and other new IT technologies are pushing its development.

External links

• Akyildiz, I.F., W. Su, Y. Sankarasubramaniam, E. Cayirci, "A Survey on Sensor Networks", IEEE Communications Magazine, August, 102-114(2002). pdf version (http://www-net.cs.umass.edu/cs791_sensornets/papers/akyildiz2.pdf)
• Chee-Yee Chong; Kumar, S.P., "Sensor networks: Evolution, opportunities, and challenges," Proc IEEE, August 2003. (pdf version (http://www-net.cs.umass.edu/cs791_sensornets/papers/chong.pdf))