A simple anchor-free localization scheme for wireless sensor networks

This paper proposed a simple anchor-free localization scheme for wireless sensor networks. The scheme makes use of a moving mote (henceforth LOCOMOTE) to localize the deployed stationary sensor motes. This moving mote travels along the perimeter of the deployment area and broadcasts localization messages as it locomotes. The stationary sensor motes localized themselves in real time based on message timestamps or odometric reading received at each transient reference point created by the moving mote. Three simple distributed localization algorithms are proposed. Unlike most existing localization algorithms, the proposed algorithms determine the x and y coordinates independently. The negligible energy cost is O(2.m) where m is the number of messages received by a sensor mote. Experimental results demonstrate that the proposed localization scheme can achieve average localization error of 2 meters with no more than 122 messages.