News for hackers. Stuff that matters.

A comment on Cellular outage in U.S. hits AT&T, T-Mobile and Verizon users. Parent comment

Re:Cellular outage in U.S. hits AT&T, T-Mobile and Verizon u... by sobriquet9 on Thursday February 22, 2024 @04:16PM (#39473369)
From cold start. Most starts are not cold. The phone knows where it is, approximately, what time it is (within a second or so, from built-in RTC), and orbital parameters of the satellites overhead (maybe without the latest corrections).

My Garmin watch gets a GPS lock in way less than 5 minutes without any cellular connection.

[ Parent | on HN ]
Re:Cellular outage in U.S. hits AT&T, T-Mobile and Verizon u... by rany_ on Friday February 23, 2024 @09:40AM (#39481082)
Actually, your Garmin probably gets A-GPS data uploaded to it via the app.

I think that because Huami/Amazfit/Xiaomi smartwatches already do that. We know this from reverse engineering efforts in Gadgetbridge, but support for Garmin is still new and so there isn't as much info about it; either way it probably works in the same way.

[ Parent | on HN ]
Re:Cellular outage in U.S. hits AT&T, T-Mobile and Verizon u... by scarface_74 on Friday February 23, 2024 @12:21PM (#39483448)
My first GPS Garmin watch used for running back in 2011 didn’t have an app and didn’t have any cellular signal. I put it on my wrist and started running. I don’t remember it taking more than a minute to get a signal.
[ Parent | on HN ]
Re:Cellular outage in U.S. hits AT&T, T-Mobile and Verizon u... by sobriquet9 on Saturday February 24, 2024 @09:00PM (#39496916)
No, it's not paired to the phone, and there is no Garmin app on the phone either.
[ Parent | on HN ]