Wireless Sensor Network: An Overview

Wireless Sensor network are dense wireless networks of small, low-cost sensors, which collect disseminate environment data. Wireless sensors networks facilitate monitoring and controlling of physical environments from remote locations with better accuracy. They have applications in a variety of fields such as environmental monitoring, military purpose and gathering sensing information inhospitable locations. Sensor nodes have various energy and computational constraints because of their inexpensive nature and ad-hoc method of deployment. Considerable research has been focused at overcoming these deficiencies through more energy efficient routing, localization algorithms and system design. Our survey attempts to provide an overview of these issues as well as the solutions proposed in recent research literature. 1.Applications of sensor network Researchers expect that the usage of wireless sensor networks will facilitate many existing applications and ultimately enable a multitude of new ones. Obviously this grand vision is depends on achieving the requirements discussed in the previous section as well as those imposed by the application. A primary constituent is the connection of the node to the physical world that is achieved by the sensing device attached. Common sensing devices are: (1) temperature, (2) humidity, (3) light, (4) pressure, (5) acceleration, (6) acoustic, (7) vibration for seismic disorder. Some more sophisticated sensing devices include: (8) Chemical sensors for soil composition and water/air quality, (9) magnetometers, (10) mechanical sensors, and (11) ECG and other sensors for medical applications. A sensor unit might control an actuator to trigger a physical action such as turning on/off an engine or a light. The literature proposes a wide range of applications for wireless sensor networks that can be grouped in 7 main categories