A mobile beacon based method for wireless sensor networks localization

The node localization technology is a foundation technology to wireless sensor networks, and a mobile beacon node based two-step localization algorithm is proposed in the paper. The main idea of the proposed algorithm is to use the mobile beacon node to traverse the entire network and to broadcast periodically the packet containing its current location information. Then the unknown sensor node can calculate its location as long as it has received enough location information packets. The method is divided into two steps: firstly, three noncollinear location information of beacon are selected to calculate the nodepsilas coarse location using the trilateration method, secondly, this coarse location serves as the initial state of the unscented Kalman filter (UKF) based localization algorithm, to get higher precise position. Simulation compared the localization error of the two-step localization algorithm among that of UKF based algorithm and trilateration algorithm, when the beacon mobile along multiple different trajectories. The results showed that the two-step localization method has not special restrict and obtains ideal localization accuracy.