Table 2.

A non-exhaustive list of real-time location systems (RTLS) and applications thus far along with their specifications. (NLoS = no line of sight, LoS = line of sight,

Technology	Application	Dynamic accuracy	Detection range	Transmission frequency range	References
mmWave (5 g)	Human Pose detection	Up to < 0.02 m @ LoS	> 200 m@ outdoor	30–300 GHz	[47, 48]
Active radio-frequency identification (RFID)	Indoor location detection of devices and people	0.9 to 1.6 m@ NLoS	50–95 m radius with possible scalability to 1000 m @ outdoors	433	[42]
3D-Light Detection and Ranging (LiDAR)	Precision vehicle localization	0.01 to 0.2 m @LoS	~ 200 m @ LoS, both outdoor and indoor	~ 200 Thz	[49]
Wireless Fidelity (Wi-Fi)	Indoor and outdoor positioning for smartphones	1–3 m @NLoS	< 200, @ outdoor and < 60 m indoor under Wi-Fi covered distance	2.4 to 5 GHz	[42]
Ultra Sound	Indoor location	Up to 0.01 m @ LoS and ~ 0.02 @ NLoS	Up to 10 m @LoS indoor	1–20 MHz	[46, 50]
Bluetooth	Real-Time Indoor Positioning	Typically, between 2 and 5 m but can go up to 0.77 m using different signal processing algorithms	Up to 2 m @ NLoS	2 MHz of width in the 2.4 GHz band	[40, 51]
Ultra-Wide Band (UWB)	Tracking and position detection in sports	Between 0.08 and 0.2 m @ LoS	40–80 m	3.1 to 10.6 GHz	[42, 46, 52]
Computer Vision	Tracking of ball in sports such as Tennis and Cricket	Up to 0.05.–0.1 m @ 340 fps	N/A	N/A	[40, 53]
	Tracking path length of multiple objects	Up to 8.5% error and under 1 m for marker-based solutions	N/A	N/A
Global Positioning System (GPS)	Measuring real-time movement of soccer players in a test situation	Up to 1.31 m/s error while measuring velocity and 6.05% error when measuring position @ NLoS	> 100 km Outdoor and Indoor	1575.42 MHz and 1227.6 MHz	[54]
Global Navigation Satellite System	Smartphone Location	Up to a few centimeters but unstable	> 100 km Outdoor	1–2 GHz	[55]