Evolution of Indoor Positioning Technologies: A Survey

Table 2

Comparison of main indoor positioning technologies. UC: end user cost; IC: installation and maintenance cost; H: high; L: low; ML: multiple levels.

IPS	Technology	Approx. accu.	Coverage	Cost		Strengths	Weaknesses
				IC	UC
Technologies with signal encoding
[22]	Infrared	57 cm–2.3 m	Room	H	L	Cheap for user	Sunlight interference
[23]	VLC	10 cm	Building (ML)	H	L	Cheap for user, unintrusive	Expens. infrast.
[24]	Ultrasonic	1 cm–2 m	Room	H	H	Good precision	Cost, interfer.
[25]	Audible sound	Meters	Room	L	L	Low cost	Low precision
[26]	Wi-Fi	1.5 m	Building	L	L	Low cost, good precision	Vulnerable to access point changes
http://research.nokia.com/news/11809	Bluetooth	30 cm–meters	Building	L	L	Low cost, good precision	Intrusive; needs signal mapping
[27]	ZigBee	25 cm	Building	L	H	Could reuse infrastructure	Low precision; user needs special equip.
[4]	RFID	1–5 m	Room	H	L	Very low cost passive side	Very low precision
[28]	UWB	15 cm	Building	H	H	High precision	High cost
Passive technologies without signal encoding
http://www.indooratlas.com/	Geomagnetic	2 m	—	L	L	No need for infrastructure, good precision	Requires mapping
[29]	Inertial	2 m	—	L	L	Low cost, private	Accumulates error
[30]	Ambient sound	Meters	—	L	L	Cheap, not intrusive	Not accurate, sensitive to changes
[23]	Ambient light	10 cm–meters	—	L	L	Cheap	Sensitive to sunlight and changes such as a bulb and a window
[9]	Computer vision	1 cm–1 m	—	L	L	Low cost, privacy if cellphone camera is used	Sensitive to light conditions