Introduction - If you have any usage issues, please Google them yourself
Wireless Sensor Networks have been proposed for a multitude of
location-dependent applications. For such systems, the cost and
limitations of the hardware on sensing nodes prevent the use of
range-based localization schemes that depend on absolute pointto-
point distance estimates. Because coarse accuracy is sufficient
for most sensor network applications, solutions in range-free
localization are being pursued as a cost-effective alternative to
more expensive range-based approaches.