Table 1.

The commonly used indoor localization techniques.

Method	Technology	Accuracy	Pros	Cons
WiFi [19]	* RSSI fingerprinting	1–2 m	Low cost, simple system	Data base required for fingerprinting, low accuracy
UWB [20]	† ToA/TDoA/AoA	0.1–1 m	High accuracy, simple system	Short range problems in NLoS
RFID [21]	RSSI	Connectivity range	Low power, low cost	Low accuracy, one tag per location, complex system
Inertial measurement [22]	Acceleration, angular velocity, magnetometer	1–5% of the traveling distance	Compact size, low cost, NLoS #	Position/orientation drift, magnetic disturbance, accumulated error in calculation

* RSSI: Received signal strength indicator; ^† ToA/TDoA/AoA: Time or arrival/time difference of arrival/angle of arrival; ^# Non-line-of-sight.