People use their laptops during "Working everywhere" event in Riga May 31, 2013.
People use their laptops during "Working everywhere" event in Riga May 31, 2013. Reuters/Ints Kalnins

Wi-Fi passwords could be a thing of the past with a new tool that uses wireless signals to accurately pinpoint users’ location. Researchers at Massachusetts Institute of Technology (MIT) in the US have developed Chronos, which could eliminate passwords for Wi-Fi.

With Chronos, the research team from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL), led by Professor Dina Katabi, hoped to enable a single Wi-Fi access point to locate users without any external sensors. Chronos is said to be 20 times more accurate than existing localisation methods used by Wi-Fi devices.

It locates users by calculating the “time-of-flight” of data travel from the wireless signals to an access point. Since Wi-Fi lets users hop on different frequency channels, Chronos is programmed to jump from one channel to another to gather many measurements of the distance between access points and users. It then automatically uses all the measurements to determine the distance.

One practical application of the tool is eliminate the use of Wi-Fi passwords. This could be used by small businesses to prevent non-customers from using their Wi-Fi. Experiments conducted showed that the system could distinguish in-store customers from outsiders with 97 percent accuracy.

The team also conducted experiments in a two-bedroom apartment with four occupants to test the tool. The results showed that Chronos can correctly identify which room a resident was in 94 percent of the time.

“Imagine having a system like this at home that can continuously adapt the heating and colling depending on number of people in the home and where they are,” Katabi said (via MIT News). “Eliminating the need for cooperation between Wi-Fi routers opens up many new exciting applications for localisation.”

Chronos could also be used to safely fly drones. As the video released by the team researchers suggests, drones could maintain a safe distance from people with a margin of error of about four centimetres.

“From developing drones that are safer for people to be around, to tracking where family members are in your house, Chronos could open up new avenues for using Wi-Fi in robotics, home automation and more,” PhD student Deepak Vasisht, a first author on the research alongside Katabi and former PhD student Swarun Kumar, said. “Designing a system that enables one Wi-Fi node to locate another is an important step for wireless technology.”

YouTube/MITCSAIL