The principle of UWB (Ultra-wideband) is to use Time of Flight (ToF) for precise ranging positioning. It is a fast, secure, and low-power radio protocol used to measure distance or determine location with high accuracy compared to other wireless technology. By sending signal at a certain frequency and continuously the time gap between signal sending and receiving with devices in known locations, UWB can accurately calculate the distance between the two points or even accurately calculate the location of the positioning tag through a certain algorithm.