Novel PIT Localization Algorithm based on Coverage of Anchors in WSN

Abstract

Lots of applications in Wireless Sensor Networks (WSN) are related to location information. The cost of the hardware on WSN nodes hinder the application of distance-based localization technologies that depend on absolute point-to-point distance measurement. Schemes in distance-independent localization are being put forward instead of more expensive distance-based algorithm. APIT is one of typical distance-independent algorithms. But APIT algorithm requires that all participating anchor nodes are within a single hop from the location-unknown node (test node) and demands that nodes’ density is large enough to ensure that in any direction on the test node there exists at least one node, which is difficult to meet in practical WSN. Starting with APIT location algorithm in WSN, a novel Point In triangle Test (PIT) algorithm based on coverage of anchors is proposed in this paper. The novel algorithm looks for the anchors’ set within the intersection of coverage area formed by selected anchors and calculates the center of gravity of the anchors’ set. If the center of gravity is in the triangle formed by the selected anchors, the test node is inside the triangle. Otherwise, the test node is outside the triangle. The simulation results show that the accuracy of the novel algorithm is increased by about 20% compared with APIT algorithm.