Skip to main content

‘No Wi-Fi beyond this point’: new tech could block access based on location

coffee shop wifi
Monkey Business Images/Shutterstock
Imagine blocking your Wi-Fi network entirely from extending to anyone outside your home or business. This could provide a nice additional layer of security, and it’s becoming possible thanks to, among other things, the speed of light.

Chronos is a new system that allows a single Wi-Fi access point to physically locate connected users, meaning a router equipped with the system could block users just a few inches outside a cafe. (Nobody tell Starbucks about this, okay?)

Recommended Videos

A team led by professor Dina Katabi at the Massachusetts Institute of Technology (MIT) created the system, and then put it to the test. Experiments in a two-bedroom apartment show Chronos can figure out which room a resident is in 94 percent of the time. Another test, in a cafe, showed Chronos to be 97 percent accurate in determining whether someone was inside the store or not.

Please enable Javascript to view this content

It’s always been possible for some Wi-Fi networks to track users — if a network uses three or more access points, that will be enough for triangulation. So how does Chronos work with only one access point? In part by calculating the “time-of-flight,” or the time it takes for data to make it from the router to a phone or laptop, with extreme accuracy. The team discovered a way to calculate time-of-flight with an average error of only 0.47 nanoseconds (a nanosecond is one billionth of a second, so yeah: that’s pretty accurate). Multiply that time-of-flight speed by the speed of light and you’ve got a precise idea of how far away the user is, within a couple of decimeters.

“Knowing both the distance and the angle allows you to compute the user’s position using just one access point,” said PhD candidate Deepak Vasish. “This is encouraging news for the many small businesses and consumers that don’t have the luxury of owning several access points.”

Combine this with an accurate calculation of the angle and you’ve got a pretty precise location.

So what could this be used for? Stopping people from outside a coffee shop from leaching the Wi-Fi, for one thing, but also to enable drones to stay away from smartphone-carrying humans.

“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,” said Vasish. “Designing a system that enables one Wi-Fi node to locate another is an important step for wireless technology.”

It’s a fascinating piece of tech that could come to a router near you. Go ahead and read MIT’s summary of the research if you want to learn more.

Justin Pot
Former Digital Trends Contributor
Justin's always had a passion for trying out new software, asking questions, and explaining things – tech journalism is the…
TP-Link’s new blazing-fast Wi-Fi 6E routers coming later in 2021
tp link new wi fi 6e routers ces 2021

 

TP-Link is introducing a refreshed lineup of routers with support for the Wi-Fi 6E standard. Announced on the first day of CES 2021, the new networking solutions are just the start of new tech coming out of the show so far.

Read more
1Password vs. NordPass: which password manager is best in 2025?
1Password and NordPass reviews appear beside one another on a PC monitor.

1Password and NordPass are among the most popular and best password managers available. Both offer significant improvements over the built-in solutions you get from Microsoft, Apple, and Google, making it hard to choose between them.

I've reviewed the latest versions of 1Password and NordPass in 2025 and can share some insights into the differences and compare prices to help you discover which offers the best value for you.
Specs

Read more
This iBuyPower gaming PC with RTX 4060 is under $1,000 — for now
The iBUYPOWER Trace 7 Mesh gaming desktop on a white background.

Gaming PC deals worth buying still usually cost more than $1,000 after the discounts, but here's an offer from Best Buy that's available for a more affordable price. The iBuyPower Trace 7 Mesh, which is originally sold for $1,300, is down to just $900 following a $400 discount. We're not sure how much time is remaining before this bargain ends, so if you're interested in this gaming desktop, you need to push forward with your purchase immediately if you want to secure the savings.

Why you should buy the iBuyPower Trace 7 Mesh gaming PC
The iBuyPower Trace 7 Mesh is a relatively affordable gaming PC, but it doesn't sacrifice much in terms of performance. It runs on the AMD Ryzen 7 5700 processor and the Nvidia GeForce RTX 4060, which is in our list of the best graphics cards as our recommendation for 1080p gaming. It has 16GB of RAM, which is the best place to start for a gaming PC, according to our guide on how much RAM do you need. With these components, you won't have trouble playing the best PC games, though you'll have to go with medium settings for the more demanding titles.

Read more