MIT Develops Accurate System For Tracking People, Objects Via WiFi (softpedia.com)

An anonymous reader writes: MIT's Computer Science and Artificial Intelligence Laboratory has created a new system called Chronos that can accurately detect the position of electronic devices in a room -- as well as the users who are carrying them -- within tens of centimeters using Wi-Fi signals only. "Chronos works without the aid of any secondary sensors, only using a technology called time-of-flight calculation, which measures the time it takes data to travel from the WiFi access point to the user's device," according to an article on Softpedia, citing a paper (PDF) that the researchers presented at a USENIX symposium in March. "MIT researchers say that by multiplying the time-in-flight value they receive from each user with the speed of light, they were able to detect each user's distance to the central Wi-Fi access point."

Comments

Sounds familiar

[blindseer]

I recall seeing the timing between stations on a wireless network being a common tactic to secure a network. If a station did not reply within a window defined by the time it would take for light to travel plus the time it would take for a secured device on the network to compute a reply then the packet was discarded. I'm sure that there are other methods to respond to such a packet beyond merely discarding it.

They seemed to make a big deal out of being able to do this with a single access point. Reading further I notice that they use other Wi-Fi devices on the network to compute a location which means that with only a single device on the network the ability to determine the location of that single device is diminished. To assure the location of a device they'd still need multiple access points and/or multiple client devices.

I assume that they take advantage of the MIMO capability of Wi-Fi devices that did not exist only a few years ago. This again is much like having multiple Wi-Fi access points, just treat each input and output antenna as a separate device and compute the location that way.

Perhaps I'm missing something important here but I'm not impressed.