Review of lifetime optimization techniques in Wireless Sensor Networks

In the recent years, the technology of wireless sensor networks has gained a lot of importance. Wireless sensor networks are a special case of ad-hoc wireless networks. A wireless sensor network is a collection of sensor nodes that communicate through wireless links to work together to carry out functions. The sensor nodes’ basic function is to monitor the physical and environmental changes in terms of pressure, humidity, temperature etc. (referred as sensing). Sensor nodes have processing, communication and sensing capabilities. WSNs are used in number of diverse scenarios including area monitoring, health care monitoring, air pollution monitoring, natural disaster prevention, industrial health monitoring, calamity prevention etc. Sensor nodes have small batteries with limited power. Large number of sensor nodes in WSN makes it impractical to replace sensor node batteries. Thus the life time of sensor nodes is an important attribute of a wireless sensor network. The life time of a sensor network is the time spent from the deployment to the instant when the network is considered non-functional. This paper presents a survey of different techniques to optimize the lifetime of the sensors in WSN. We have tried to find out problems that exist with lifetime optimization and have tried to present solutions for the same.