Algorithmic Aspects of Localization

Wireless sensor networks (WSNs)are composed of large number of sensor nodes which are densely deployed or sparsely deployed and have displaced the well-established and widely deployed wired communication networks of the past. If we deploy nodes randomly then the need of determining the location of sensor nodes is vital otherwise the assessment of information will be in vague. The knowledge of the physical location of mobile user devices, such as phones, laptops and PDAs, is important in several applications such as network planning, location based services and for improving network performance. Location of node or device is estimated by monitoring distance based parameter (angle of arrival, time of arrival, signal strength) and connectivity or hop.Awareness of location is one of the critical issuesand vital and big challenge in WSNs. Uses of Localization of nodes is required to monitor the origin of events (flood detection, application bush fires and military surveillance etc.) and transmittinginformation to the base station. In this paper we have reviewed a broad class of localization schemes, estimation approaches and parameter and presented the various localization algorithms and compared their acceptance.