Table 1: Previous surveys comparison, including ours. “Passive” means that the infrastructure generates the signal and that the object or person to be located receives it.

Technology or feature Liu Gu Mautz Deak Koyuncu Ours

Infrared mobile readerNo Yes No No No Yes
Infrared badgeMention Yes Yes Yes Yes Yes
Laser (passive)No No Yes No No No
Ultrasound passiveNo Yes Yes No Yes Yes
Ultrasound activeMention Yes Yes Yes Yes Yes
Audible sound activeNo Yes Yes No No Yes
Audible sound passiveNo No No No No Yes
Audible sound ambientNo No No No No Yes
Magnetic generatedNo Yes Yes No No Yes
Magnetic ambientNo No Yes No No Yes
RFID mobile tagYes Yes Yes Yes Yes Yes
RFID mobile readerNo No Yes No No No
Wi-FiYes Yes Yes Yes Yes Yes
BluetoothYes Yes Yes Yes No Yes
ZigBeeNo No Yes No No Yes
UWBYes Yes Yes Yes Yes Yes
Tomographic (water resonance)No No No Yes No No
Cameras infrastructureMention Yes Yes Yes Yes Yes
Cameras (portable)No No Yes No No Yes
Floor tilesNo No Yes Yes No No
Air pressureNo No Yes Yes No No
InertialNo No Yes Mention Yes Yes
Ambient lightNo No No No No Yes
Artificial light (no encoding)No No No No No Yes
Artificial light (encoded)No No Yes No No Yes
Indoor AGPS, pseudolitesYesNo Yes No Yes Yes
CellularYesNo Yes Mention Yes Yes
TV, FMNoNoYes Yes No Yes

Classification-guidedPartialPartialNoYesPartialYes