“…Currently available indoor positioning systems include cellular network-based systems [ 8 , 9 , 10 , 11 ], single frequency network-based systems [ 12 , 13 , 14 , 15 ], ultra-wide band (UWB)-based systems [ 16 ], wireless local area network (WLAN)-based systems [ 17 , 18 ], radio frequency identification (RFID)-based systems [ 19 , 20 ], dead-reckoning-based systems [ 21 ], Bluetooth indoor positioning systems [ 22 ] and pseudolite-based systems [ 23 ]. Among them, the received signal strength (RSS)-based WLAN indoor positioning system is the most popular technique employed [ 24 , 25 , 26 , 27 ].…”