A review of Indoor Positioning Techniques

A great development has been appeared in wireless technologies and location based services and especially with appearance of open android operating system. In outdoor environments, Global Positioning System (GPS) can be used to get the position of smartphone users but GPS receiver is mostly inefficient in indoor environments. In this paper, several positioning systems have been reviewed which are used different technologies such as WLAN networks, cellular networks, infrared and ultrasound based system. Many comparison metrics between positioning techniques have been mentioned such as measurement type, accuracy, coverage, line of sight or non-line of sight, affected by multipath and cost and the best technique can be obtained through these metrics.