3 ms·

Bluetooth uses frequency hopping, which is unsuitable for measuring TOF. This group tried it: https://hal.inria.fr/hal-01995171/document https://hal.inria.fr/ha

by tlb 7y ago

Bluetooth uses frequency hopping, which is unsuitable for measuring TOF. This group tried it: https://hal.inria.fr/hal-01995171/document https://hal.inria.fr/hal-01995171/document and even with a lot of cleverness they were seeing 100 foot RMS errors from Bluetooth. Not enough to prevent stealing someone's car parked in their driveway while their phone is in the house.

amluto 7y ago
They’re using unmodified hardware and minimally modified software. It would be interesting to see how much precision could be achieved with hardware modifications.
- jazzyjackson 7y ago
  Well sure, but at that point is it still Bluetooth?
- kalleboo 7y ago
  Instead of Bluetooth (which Apple could totally fudge on their own devices if they wanted to), the TOF for the Apple Watch<>Mac auto-unlock uses Wi-Fi 802.11v. It seems really quick too (presumably the Mac is establishing a short-lived AP), would work fine for unlocking a car.
  - Operyl 7y ago
    Here’s a good article further explaining it for those curious: https://networkingnerd.net/2016/09/21/apple-watch-unlock-802-11ac-and-time/ https://networkingnerd.net/2016/09/21/apple-watch-unlock-802...
deleted 7y ago
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