Wi-Vi Developed At MIT Will Let You See Humans Behind Walls

By Amit Chowdhry ● Jul 1, 2013

You know how Superman has the ability to see bad guys behind walls using X-ray vision?  The Computer Science and Artificial Intelligence Laboratory at the Massachusetts Institute of Technology are developing a similar technology for us mere mortals.

The system is being developed by MIT Department of Electrical Engineering and Computer Science professor Dina Katabi and graduate student Fadel Adib.  It will give people the ability to see people in different rooms using low-power WiFi.  This new technology is called Wi-Vi and it uses similar concepts as radar and sonar imaging.  Wi-Vi transmits a low-power Wi-Fi signal and uses its reflections to track humans that are moving even if they are behind walls.

“We wanted to create a device that is low-power, portable and simple enough for anyone to use, to give people the ability to see through walls and closed doors,” stated Katabi.

The problem with the project is that a fraction of the signal penetrates through the wall and the rest of it is deflected by the wall and other objects.  This project requires the ability to capture the signals from the moving human body.

“To do this, the system uses two transmit antennas and a single receiver. The two antennas transmit almost identical signals, except that the signal from the second receiver is the inverse of the first. As a result, the two signals interfere with each other in such a way as to cancel each other out. Since any static objects that the signals hit — including the wall — create identical reflections, they too are cancelled out by this nulling effect,” said MIT in a statement.  The device developed at MIT uses a single receiver to track people as they move through a certain space.

Wi-VIi will be demoed at the Sigcomm conference in Hong Kong this August.  A practical use of this technology is a search team looking for survivors trapped after an earthquake.  Check out the demo of the technology in the video below: