Certain approaches to improve network lifetime in wireless sensor networks

Abstract

Energy efficiency is the need of the day in Wireless Sensor Networks (WSN). Only the network that lives long, will prove worthy for the effort and cost spent in establishing it. A network s lifetime is considered as the time till which the first sensor node or a group of sensor nodes run out of energy. Apart from energy efficient strategies, there are few other ways to increase a network s lifetime like using solar paneled sensor nodes, using double storage nodes which could scavenge energy from environment, wireless energy transfer, harvesting energy from natural phenomena etc. But many of the above technologies are in beta phase or under research. Even with solar powered nodes, uninterrupted power supply is not guaranteed. Hence, energy efficient strategies for various functionalities of a sensor network become inevitable. The aim of this thesis is to propose a few energy efficient strategies to increase the lifetime of a WSN. On analyzing the power system of a sensor node, it is observed that its radio component is more power hungry than its sensing and processing counterparts. Hence, all the proposed strategies in this thesis are focused on optimization of communication in WSN. Methods have been proposed in the areas of Localization/Positioning of sensor nodes and Sleep Scheduling. Localization is the process which enables the sensor nodes to know their physical location. Generally, they are categorized based on the method used for positioning. Methods which use absolute range estimations like distance or direction of arrival are called Range based and the ones which use message from anchors are called Range Free. newline