First, came WiFi, that essential technology that keeps us online – provided we have the one PC hooked up to the cable modem and router, and the another PC with a wireless networking card.


Then came WiVi, which uses WiFi technology to “see” through walls to detect motion. According to, the US Navy discovered radar when they noticed  that a plane going past a radio tower reflected radio waves. Much more recently, Massachusetts Institute of Technology (MIT) scientists applied this same idea to create devices that can monitor human (or possibly other) movement by tracking the WiFi signal frequency changes in buildings or behind walls.


And now, we have WiTrack. MIT scientists have taken the WiVi idea a step further. The MIT article, WiTrack: Through-Wall 3D Tracking Using Body Radio Reflections, describes WiTrack as “…a device that tracks the 3D motion of a user from the radio signals reflected off her body…WiTrack does not require the user to carry any wireless device, yet its accuracy exceeds current RF localization systems, which require the user to hold a transceiver. It transmits wireless signals whose power is 100 times smaller than Wi-Fi and 1000 times smaller than cellphone transmissions.”


Applications for WiTrack


Applications for WiTrack are really varied, and include:


  • Security and law enforcement, from detecting intruders to avoiding or minimizing potentially violent situations, such as in battle or at a crime scene.
  • Rescue operations, for detecting motion inside hard-to-get-to places, such as collapsed buildings or avalanche sites.
  • Gaming, in which you can freely move about your home to participate in the fun. Imagine running down the hall and up the stairs as part of the gaming experience…
  • Monitoring, any three-dimensional being  who might need to be checked in on - from your new puppy, to your kids, to your great grandmother. MIT points out that a WiTrack monitoring system can do what current camera-based monitoring systems do without using cameras to invade anyone’s privacy. 


Find Out More


For even more details on WiTrack, check out the video, WiTrack: 3D Motion Tracking Through Walls Using Wireless Signals And for all the details on how WiTrack works, see the MIT paper, 3D Tracking via Body Radio Reflections.