Study on Range Free Localization in Wireless Sensor Network (WSN)

Abstract

The position accuracy of range free localization is a fundamental problem in Wireless Sensor Networks (WSNs). The accuracy of the localization algorithm greatly impacts the performance of the localization dependent protocols and applications, such as routing and storage. Most of the range free localization algorithms are designed by assuming that the sensor nodes are deployed in regular areas without any obstacles. This assumption does not reflect the real-world conditions, especially for outdoor deployment of WSN. In this paper we propose a novel scheme called Range Free Angle Calculation (RFAC) based Sensor Localization in WSNs, which can greatly reduce the localization error in the irregular deployment areas. We estimate the average hop distance by selecting the middle of the transmission path between every two anchor pairs one by one. Then the estimated hop distance is adjusted by the angle between the anchor pairs to that selected middle point. The simulation results show that RFAC achieves significant improvement in localization accuracy in anisotropic WSNs