Learning and focusing

The Radio Wave Display (RWD by Luxondes) shows in real time the waves that pass through it. The TRIMARAN project's prototype of focusing antennas generates a focused radio communication that is visible on the RWD.
In a first step, a target antenna is emitting a "ping". The focusing antennas (not visible on the video) use the recorded "ping" and its echoes to learn how to focuse towards the target antenna (using Time Reversal technique).
In a second step, the focusing antennas send data to the target antenna in a focused manner.
Every thing is slowed down for the public to see the two steps.
In a real life system, the focusing antennas are faster and can track a slow moving (pedestrian) target.
To track a car or a train, some innovations are proposed here:
https://recherche.orange.com/en/focusing-antennas-for-a-green-5g-a-project-awarded-with-the-economic-impact-prize-by-the-french-research-agency/