Estimating the positions of sensor nodes is a fundamental and

crucial problem in ad hoc wireless sensor networks (WSNs).

In this paper, an accurate node localization method for WSNs

is devised based on the weighted least squares technique with

the use of time-of-arrival measurements. Computer simulations

are included to evaluate the performance of the proposed

approach by comparing with the classical multidimensional

scaling method and Cram´ er-Rao lower bound.