Abstract: A localization algorithm based on Monte Carlo suitable for mobile wireless sensor network was proposed.Each mobile anchor emits beacons at different power levels. From the information received by each unknown node, the sensor node can determine which particular ring or inner circle it lies within from that anchor, which is called constraint region. The positions of unknown nodes are able to be estimated by few samples based on an improved Monte Carlo Localization scheme. Collincarity Limiting Factor(CLF) was introduced to avoid localization failure which is caused by Beacon Collineation, and a scheme of beacon selection was put forward. Simulation results show that the proposed algorithm has a lower localization error and better flexibility under different factors,such as anchor density,moving speed,ranging error and so on.

Key words: Wireless sensor network, Energy-level, Localization, Monte carlo, Collinearity