It's an adventure that we've all probably had to share: you're sitting comfortably on the terrace of a bistro and you need to connect. At your request, the waitress will spell out, usually kindly, the access code to the establishment's wifi. A sequence of letters, numbers, capitals and lower case letters. The mistake every time. A tedious process that should soon disappear thanks to the ingenious invention of two MIT researchers.
Desearchers at the Massachusetts Institute of Technology (MIT) want to change the way we connect to Wi-Fi. To do this, they have developed a way to grant access to a network based on proximity to the router. Each wifi terminal is thus configured to accept connections in a given area, delimited to the nearest quarter of a metre.
In practice, this means that as soon as you enter a café, you are automatically connected to the establishment's network; if you leave the café, your connection is terminated. This is also true for your home network. When you enter your apartment, your friends or visitors will automatically be connected to your wifi terminal.
It's simple. How could you not have thought of that earlier.
It turns out the technology is not trivial. It's called Chronos and was developed in the Computer Science and Artificial Intelligence Laboratory from MIT and operates with an accuracy of 97 %. Researchers are able to define location parameters in the order of 10 centimetres. Their brilliant idea is to calculate the time it takes for a piece of data to travel from the transmitter to the receiver. The calculation of this "time of flight" allows locations that are twenty times more precise than all current systems, with a margin of error of less than 0.50 nanoseconds.
The system is thus able to calculate the distance and angle of a transmitter by multiplying the time of flight by the speed of light. According to our colleague numeramaThe system uses the capacity of the access point to switch from one channel to another over a spectrum of 2.5 Ghz to 5.8 Ghz, but this time very quickly (every two or three milliseconds). By switching from one channel to the other, Chronos recovers the different measurements it will use to complete the distance between the access point and the connected objects.
Although it is at an experimental stage, the potential of this technology is immense. Applications in home automation and the Internet of Things can be imagined by locating objects precisely inside the house. Researchers are also thinking of original applications such as the means of maintaining a static safety distance between a drone and its operator.