“We developed a deep neural network that maps the phase and amplitude of WiFi signals to UV coordinates within 24 human regions. The results of the study reveal that our model can estimate the dense pose of multiple subjects, with comparable performance to image-based approaches, by utilizing WiFi signals as the only input.”
There are already smart light bulbs you can buy off the shelf that use radio signals to see when somebody is in the room. Then it can turn on the lights automatically, without a camera or infrared sensor in the area.