A Distributed Localization Algorithm for Wireless Sensor Network Based on the Two-Hop Connection Relationship

Sensor’s position is extremely crucial for the configuration and applications of wireless sensor network (WSN). In this paper, a novel range-free and distributed localization (THCRL) algorithm was proposed for WSN based on the two-hop connection relationship of a node. In THCRL algorithm, the information of one-hop and two-hop anchor nodes is firstly collected by an unknown node through broadcasting. Then, two regions, which are called as NSR and OCR, are computed when the collected information of anchors’ position is viewed as geometric constraints. The NSR is a geometric constraint to the position of an unknown node that its two-hop anchor nodes should be out of its communication range. The OCR is another geometric constraint to the position of an unknown node that it should locate at the overlap of communication range of its one-hop anchor nodes. Finally, for each of unknown nodes, the overlap of NSR and OCR where it resides is determined through the method of grid search and the estimated position is obtained based on the grid with the highest score. Simulation results show that the THCRL algorithm has better performances on positioning precision, energy efficiency and robustness to irregularity of communication range, which can meet the requirements of node localization in WSN.