Research of localization algorithm based on weighted Voronoi diagrams for wireless sensor network

Shaobin Cai,Zhenguo Gao,Nianmin Yao,Zhiqiang Sun,Hongqi Pan

doi:10.1186/1687-1499-2014-50

Abstract

Wireless sensor network (WSN) is formed by a large number of cheap sensors, which are communicated by an ad hoc wireless network to collect information of sensed objects of a certain area. The acquired information is useful only when the locations of sensors and objects are known. Therefore, localization is one of the most important technologies of WSN. In this paper, weighted Voronoi diagram-based localization scheme (W-VBLS) is proposed to extend Voronoi diagram-based localization scheme (VBLS). In this scheme, firstly, a node estimates the distances according to the strength of its received signal strength indicator (RSSI) from neighbor beacons and divides three beacons into groups, whose distances are similar. Secondly, by a triangle, formed by the node and two beacons of a group, a weighted bisector can be calculated out. Thirdly, an estimated position of the node with the biggest RSSI value as weight can be calculated out by three bisectors of the same group. Finally, the position of the node is calculated out by the weighted average of all estimated positions. The simulation shows that compared with centroid and VBLS, W-VBLS has higher positioning accuracy and lower computation complexity.

Highlights

Wireless sensor network (WSN) is a self-organizing distributed network system including plenty of tiny sensor nodes with the ability to communicate and calculate in a specific monitoring area
Algorithm [11] using the midperpendicular of the beacon nodes as Voronoi diagram region boundaries could not reflect the relationship between the received signal strength indicator (RSSI) signal strength and the distance among the nodes
Because RSSI signal values between nodes are inversely proportional to the square of their distances, according to this property and the definition of Voronoi diagrams, we can describe WSN node localization as follows

Summary

Introduction

Wireless sensor network (WSN) is a self-organizing distributed network system including plenty of tiny sensor nodes with the ability to communicate and calculate in a specific monitoring area. Literature [11] used Voronoi diagrams in wireless sensor node localization. In this algorithm, the midperpendiculars between each beacon node and its neighbor beacon node composed the Voronoi region boundaries. In literature [11], the algorithm weighted all the nodes within this region firstly and obtained all the beacon nodes’ Voronoi regions in order, added different weight values to the obtained regions, and obtained the centroid of the largest weight value region as the estimated coordinate of the node to be located. Algorithm [11] using the midperpendicular of the beacon nodes as Voronoi diagram region boundaries could not reflect the relationship between the RSSI signal strength and the distance among the nodes. Intersection coordinates as estimate coordinates, and we regarded the weighted average values of all the estimate coordinates as the final estimate coordinates of the node to be located

Positioning algorithm based on Voronoi

Algorithm basic ideas

Findings

Conclusion