Tianwei Hou

At the heart of the system is a rail with clip-on antennas moving along it, each emitting a radio signal. The smartphone receives these and, knowing the speed of light, calculates the distance to each antenna from the time delay.

A clamp antenna system resembles a garden hose with punctures. In the waveguide cable, emission points are created where radio waves burst out, like water from a hole. Obstacles in the path block direct communication, but reflected signals can bypass the barrier.