Localization using a Mobile Beacon in Wireless Sensor Networks

Localization is a crucial issue and acts as a fundamental element in wireless sensor networks. The location accuracy of sensor node increases with the number of beacon points which can provide reference information for localization. However, the more beacons are used, the higher implementation cost is. In the study, a distributed algorithm called RSS-assisted range-free is proposed to locate sensor nodes using mobile beacons. The proposed algorithm only uses three beacon points to estimate the position of the sensor node. In the proposed scheme, two beacon points are used to obtain candidate positions of the sensor node and the third beacon point is used to determine which one of the candidates would be the actual position of the sensor node. To improve the location accuracy, the study estimates sensor position from possible candidate regions by using geometric conjecture and Received Signal Strength (RSS) constraints. The simulation results have shown that the proposed algorithm is feasible and significantly improves on location accuracy.