Researchers from MIT’s CSAIL team managed to achieve the feat using just a single router by measuring the “time of flight” for the WiFi signals between both the transmitter and receiving components, with a margin of error of just 0.5 nanoseconds, 20 times more accurate that other systems. Once the time was calculated they multiplied it by the speed of light, resulting in the distance between people and their wireless routers.
Using a four room apartment as an example, the researchers managed to locate the correct room for a user 94% of the time. Not stopping there the researchers took the technology to a cafe and managed to track down if someone was within the cafe with a 97% accuracy. Not stopping at wireless routers the technique was then applied to a drone, restricting the distance of the drone from the operator with an error margin of just 2-inches.
With the ability to limit or restrict access to a network by a user’s distance, public networks, and drones could be made more secure and with greater control of who, and where, people can access the systems.