At the University of California, Santa Barbara, researchers are working on developing a system by which they can count the number of people in a room or area using WiFi signals. Now, they aren’t counting the number of people who are connected to WiFi, which would be easy. They are instead using the WiFi signal to estimate how many people are in a room, whether they have WiFi capable devices on their person or not.
Basically, it works like this: When two WiFi devices communicate with each other, they create a signal between them and, if a human happens to walk through that signal, it is dispersed. This doesn’t affect the signal, otherwise having people in your house would make your WiFi work worse, and the WiFi at Starbucks would never work. However, using a probabilistic algorithm, researchers are able to look at that dispersed signal and figure out roughly how many people are disrupting it.
So far, they have tested the system both indoors and outdoors, and have had success in estimating up to nine people occupying either test space. They’re still working on developing the system, in order to get larger counts in a variety of spaces, but have presented the data they have so far in the Institute of Electrical and Electronics Engineers Journal.
The benefits of such a system working could be applied in a variety of spaces. Businesses could use readings to figure out how many customers enter their store, and at what times. Homes could use WiFi to intelligently adapt heating and cooling systems, based on how many people are in the house at any given time. And emergency response teams could use that information to figure out how many people were in a building when it started to burn, or how many people are in a building during a hostage situation.