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Comment by kube-system | Hacker News Reader

As I understand it is mostly handled by the chipset firmware these days, and no options are available to disable it because it is a legal requirement. But even if you were able to disable the functionality, the carriers towers can triangulate you.

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It's revolting that we've allowed functionality to betray its owner to be legally mandated into "our" devices. It's no surprise that they keep this so very discreet.

Edit: I am specifically referring to the e911 ability to without owner interaction or knowledge send GPS coordinates, not to network-side triangulation, or even to sending GPS coordinates when the owner initiates a 911 call.

I remember seeing it talked about on local news when it was being implemented. It was normal to list “e911 support” on the outside of phone boxes when it was a new feature. Just checked my desk drawer and it is listed on the box of one of my HTC phones and one of my Samsung phones.

E911 can also use triangulation which is isn’t “in” your phone anyway. It’s possible with any type of radio transmission due to plain old physics.

It's "your" device but you're using it to communicate with things that are not your cell phone tower or telecoms network. One can have a reasonable discussion about the circumstances under which the telco doesn't/shouldn't know where your phone is but clearly there's some point where it's a function of using your phone.

(As others have noted there may be some confusion here between GPS data and cell tower triangulation.)

Hmm. Re: chipset firmware, the GPS chip and the cellular modem are typically separate and not directly connected, right? So doesn’t that mean there is necessarily something in the main phone software that’s handling passing GPS data from the gps to the modem chip on-demand from the modem firmware?

I believe it is pretty common for LTE modems to include GNSS support these days. I know many modems for even for data-only applications do. And it sounds like Qualcomm does it on their phone modems from this description: https://www.qualcomm.com/news/onq/2021/07/27/qualcomm-locati...

Good info. Thank you.

No. We would use the baseband PMIC and DMA to move the info out of the AP if they were not integrated.

I thought the kernel had the ability to restrict DMA on modern devices. But a sibling comment indicates that modems integrate GPS support these days so I guess it's irrelevant.

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