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,

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]