An Overview of Localization for Wireless Sensor Networks

Localization is an important issue for location-dependent applications of wireless sensor networks. In Sensor networks, data collected by sensor nodes need to be tagged with time and location information. Localization techniques are used to determine the location information of a sensor node. It enables efficient routing, provides power saving, assists in the applications like target tracking, useful in locating the source of the data. The localization can be categorized as range-free or range-based schemes based on whether the range information is used among the localization process. Because of the hardware limitations of the network devices, solutions in range-free localization are being pursued as a cost-effective alternative to more expensive rangebased approaches. In this paper described recent techniques used for localization.