ABSTRACT
The Global Positioning System (GPS) is a popular location technology, but it only works in outdoor environments (Xiaowei et al. 2011; Barsocchi et al, 2009). To address the demand for location awareness in indoor conditions, some localization techniques have been proposed. An available solution for indoor localization exploits the Wireless Sensor Network (WSN). The location-based services have been recognized as a hot topic in WSN (Xiaowei et al. 2011). The WSN-based solutions can estimate the unknown location of mobile sensors (moving according to demand of the users) with respect to a set of fixed sensors, so called anchors whose position is known, by two different approaches: either range-based or range-free (Xiaowei et al. 2011; Barsocchi et al. 2009; Chan and So, 2009; Zhang et al. 2010).
