An Indoor Ultrasonic Positioning System Based on TOA for Internet of Things

Table 1

List of common indoor positioning methods.

Method	Accuracy	Complexity	Cost	Scope
UWB	Medium	Higher	Higher	lower
RFID	High	High	Low	High
ZigBee	Medium	Lower	Lower	Medium
Infrared	High	Low	High	Lower
Bluetooth	Low	High	Medium	High
WiFi	Lower	High	Lower	Higher
Ultrasonic	Higher	Lower	Lower	Medium