Towards Enhanced RSSI-Based Distance Measurements and Localization in WSNs

Despite its inherent inaccuracy, RSSI has been used as the standard tool for distance measurements in the majority of range-based localization protocols available in the literature. In this paper, we propose a technique to enhance the accuracy of RSSI-based distance measurements using calibration. Our technique depends on the existence of location-aware anchor nodes that are distributed across the deployment area. Initially and through exchanging messages between anchors, the deployment area is divided into disjoint set of Delaunay triangles. Through the power of received signals, anchors estimate a set of calibration records(CR) and distribute them to sensors in their neighborhood. Each triangle edge connects a pair of anchors and is associated with a single calibration record. Each record contains calibration parameters for sensors in the neighborhood of the record anchors. Based on the power of received messages from different anchors, sensors can determine the calibration record they should use for their RSSI-based distance measurements.