Another option would be to prevent another person to stand in the beam. This could be achieved using very strong haptic feedback from another transmitter :)
Or spread multiple transmitters around the room (or even attached to the person's suit) to (try to) prevent blockage. That could work but there are loopholes and thus it's both expensive and not theoretically satisfying.
Or spread multiple transmitters around the room (or even attached to the person's suit) to (try to) prevent blockage. That could work but there are loopholes and thus it's both expensive and not theoretically satisfying.