Essential Functions for Localization in Wireless Sensor Networks Using Geographic Coordinates

A variety of localization protocols have been proposed in the literature which allow Wireless Sensor Network (WSN) nodes to interpolate their location from their neighbors as an alternative to deploying more expensive WSN nodes with GPS receivers or other dedicated localization hardware. This paper presents a set of efficient functions applied to three base cases where a WSN node calculates an initial estimate of its location and a finite set of alternate points that could be its actual location, given the GPS coordinates and nominal transmission radius of two or three neighbors. The process of narrowing the set of possible actual locations through iterative refinement as more nodes join the network is discussed, along with the limits on the accuracy of the overall network map.