  In this paper, we propose an efficient range free localization scheme for
large scale three dimensional wireless sensor networks. Our system environment
consists of two type of sensors, randomly deployed static sensors and global
positioning system equipped moving sensors. These moving anchors travels across
the network field and broadcast their current locations on specified intervals.
As soon as the sensors which are deployed in random fashion receives three
beacon messages (known locations broadcasted by anchors), they computes their
locations automatically by using our proposed algorithm. One of our significant
contributions is, we use only three different beacon messages to localize one
sensor, while in the best of our knowledge, all previously proposed methods use
at least four different known locations. The ability of our method to localize
by using only three known locations not only saves computation, time, energy,
but also reduces the number of anchors needed to be deployed and more
importantly reduces the communication overheads. Experimental results
demonstrate that our proposed scheme improves the overall efficiency of
localization process significantly.
  Important Note: Final version of this paper is accepted and published by
Journal of Wireless Personal Communication, Springer : June, 2014 The final
version of publication is available at link.springer.com Link:
http://link.springer.com/article/10.1007\%2Fs11277-014-1852-6
