Wireless Sensor Networks (WSNs) are emerging as one of the most effective mechanism to sense, collect, process and disseminate physically dispersed information. Small sensing devices provide flexibility and ease of deployment as well as self configuring wireless networks for communication. Advances in sensor hardware resulted in a huge number of different type of sensors like: thermometers, barometers, moisture gauges, motion and glass break detectors, RFID access control badges and so many more (Conner et al., 2004). Most importantly, the economy of this type of solution is responsible for development of a huge number of applications in this area. Following are few of the interesting applications of WSNs:
Habitat monitoring requires access to the remote area which may not be safe and/or feasible to be accessed regularly for data collection. WSNs provide a robust and safe alternative and hence, a large number of such applications have developed in last few years (Szewczyk et al., 2004; Polastre et al., 2004).
Environmental observation and forecasting systems have benefited a lot with the emergence of WSNs as the means to sense, monitor, model and forecast the physical processes like rain fall, flooding, temperature changes, pollution etc.
Disaster management is the area that has emerged as the perfect candidate for applying WSN technology. Monitoring, assistance and management provided by a WSN based disaster management system provides critical information without risking human lives.
Surveillance and security in buildings and secure areas can be provided by WSNs. Motion tracking sensors are perfect to detect intruders as provide required services round the clock.
Military applications like battlefield assistance, troop management and enemy tracking are one of the driving forces behind the success of WSNs.
In addition to the above mentioned possibilities, the applications in the area of WSN are unlimited and are emerging everyday. Before going into further details, a brief and simple introduction of WSN is provided here. WSNs are essentially composed of a large number of small sensing devices, deployed in an ad-hoc manner to collectively sense a physical phenomenon (Tilak et al., 2002). The sensor nodes disseminate the collected data after limited processing to the sink node using wireless technology. The sink node can have the ability to query sensor nodes for any information. The exterior networks are connected to the sink node which enables these networks to collect data from WSN.
The following sets of distinguishing features of WSNs are responsible for a tremendous amount of research in this area (Wang et al., 2006):