A Novel Algorithm for Graded Precision Localization in Wireless Sensor Networks

A lot of research has been done in finding range-based methods such as computing RSSI, time of arrival, angle of arrival or time difference of arrival and range-free methods such as centroid computation, DV-hop and approximate position in triangle, for localization in wireless sensor networks. Range-based methods estimate location more precisely than range-free methods. However, range-free methods are cost-effective and simpler to implement for resource constrained sensor nodes. In this paper, we propose a novel localization algorithm GRADELOC to allow a mobile node to localize with graded levels of precision using a combination of (a) locally available information from the mobile node itself such as accelerometer, magnetometer and gyrometer data and (b) information derived from the infrastructure, using both range-free (centroid computation) and range-based (time difference of arrival - TDOA) methods. We present the performance of GRADELOC under different situations and suggest suitable configurations, for specific situations, that attempt to minimize the overall cost of the system while maintaining desirable results.