There’s been lots of news recently about the capabilities of using the Wi-Fi protocol in an echolocation-esque way to count people, but previous technology required people to be moving around for the transmitter/receiver feedback to be accurate. Now, researchers at UC Santa Barbara have demonstrated a method to count stationary people seated in a classroom using only a transmitter and receiver. The people in the room being counted don’t even need to have devices on them for it to work.