3D localization with a mobile beacon in wireless sensor networks

Range-free localization schemes could be a good approach to localize sensor nodes from the viewpoint of cost and energy consumption, because range-free schemes require no hardware for measuring distance or angle information. The use of a mobile beacon can improve the localization accuracy and reduce communication overhead between sensor nodes because of the mobility of a mobile beacon. A 3D range-free localization scheme with a mobile beacon proposed by Ou et al. has finegrained accuracy, scalability, and power efficiency [9]. However, Ou's scheme can have large location errors or cause failure of localization in ill-conditioned cases. To improve the localization accuracy and alleviate the failure of localization, we propose a 3D range-free localization scheme that estimates the location of a sensor node by obtaining two possible points through the intersection of three spheres with centers three reference points and making a decision between the two possible points with another reference point. Simulation results show that the proposed scheme can provide higher localization accuracy compared to Ou's scheme.