Nowadays, Wireless Sensor Networks (WSNs) are increasingly becoming popular from all over the world. The applicability of WSN is increasing day-by-day in numerous arenas. Sensed data is being collected, stored and shared using WSNs. WSNs are applicable in various fields like home control, building automation, industrial automation, medical applications, sensor and robots, reconfigurable sensor networks, highway monitoring, military applications, civil and environmental engineering applications, wildfire instrumentation, habitat monitoring and nanoscopic sensor. WSN architecture is basically divided into two types, one is layered and the other is clustered architecture where the functionality of sensor nodes to other nodes is described in detail. In this paper, we emphasize on exploring the applications of WSN in different arenas. In wireless communication, WSN has chartered a new course.

Wireless Sensor Network (WSN) comprises a combination of autonomous devices that are used in sensor nodes for checking the static and dynamic condition of external stimuli like force, echo, heat and temperature. It is responsible for transferring the data over the network to central place. It is applicable in collection of data through surroundings and includes a huge number of sensor nodes and one or more sensed devices to perform a task. As we know, it is a combination of wireless sensing and data networking. WSNs are networks that are constructed autonomous and distributed, but work in an organized way with tiny sensors. These sensors have sensing capability that are used for checking, tracing and recognition of environmental as well as physical surroundings. There are miscellaneous WSN application domains present in different arenas such as medical applications, sensor and robots, reconfigurable sensor networks, highway monitoring, etc. In this paper, we mainly concentrate on the application of WSNs in various kinds of commercial as well as noncommercial areas.

A WSN is a combination of two things, one is wireless sensing and the other data networking. Both seem to be same, but in wireless sensing, sensed data is required and in data networking, this sensed data works for collecting, storing and checking information regarding the external stimuli.

Sensor nodes are a collection of tiny devices that are producing a computable response from physical or nonphysical environmental circumstance by different deviations. Sensor nodes are low power-consumption devices which consist of one or more sensors, processor, power supply, radio, an actuator and memory (Estrin et al., 1999). There are four elementary constituents in a sensor network: first one is an assembly of distributed or localized sensors; the second one is an interconnecting network that is usually but not always wireless-based network; the third one is a central point of information clustering; and the fourth is a set of computing resources at the central point or beyond to control data association, event trending, status inquiring and data mining (Figure 1) (Kazem et al., 2007).

Information Technology Journal, Wireless Sensor Network (WSN), Sensor, Clustered architecture, Layered architecture, Application.