Abstract: WSN's are widely being used in various environments to perform various monitoring tasks, node localization is one of the most important system parameters. Determining the exact position of nodes in sensor networks is one of those vital and tedious tasks. The precise location of nodes is required to perform functions such as routing, forwarding, information broadcasting, to report the origin of tasks, support group query of sensors. To localize the nodes, we need some positions of pre-known nodes, called anchor or landmark nodes. These help in finding the locations of sensing nodes. In this paper we have discussed many different localization algorithms.

Keywords: WSN, Node Localization, DV-Hop, Anchor node.