A robust ranging-based localization mechanism in wireless sensor networks

Node Localization plays an important role in the applications of wireless sensor networks (WSNs). The whole localization mechanism of WSN target nodes consists of three key steps, the identification and data exchange step, the range estimation step, and the position estimation step. Based on the RSSI (Received Signal Strength Indication) technology, the BP (Back Propagation)-loss channel model is proposed to approximate the channel transmission characteristic adaptively by resilient gradient descent method. Due to the constraint of low powered, and low cost property of WSN nodes, the concentrative localization algorithm is adopted. The RMIC (RSSI-margin and Improved Chan) algorithm and the optimal anchor nodes library selection scheme are presented to improve the localization accuracy. The simulation results show the performance improvement of the proposed localization mechanism. Range measurement and localization are realized on our WSN nodes, and the experiment data confirm the validity of the mechanism.