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Comment by AlexanderYamanu | Hacker News Reader

euhm, well. 112 programmer here. There are multiple levels. Cell tower triangulation come in automatically from providers. But they are only in tower numbers. They might be wrongly entered by engineers, hence the confirming question about where you are. Second is subscription information, as in registered address. Chances are if called from nearby your address, you are at your address. Next is a text to your phone number, which is intercepted by firmware and sends gps coords back. This can be turned off, since implementation.

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American carriers have a different protocol than the EU. The EU (and probably EU derived networks) uses a """secret""" SMS format that's opt-in, but the 911 system works differently.

The 911 feature can be activated fully remotely, the 112 feature is supposed to only activate when dialing an emergency number.

The US one is called E911: https://en.wikipedia.org/wiki/Enhanced_911

>The 911 feature can be activated fully remotely

Source? Even if the phone isn't actively doing a 911 call?

GP likely means any 911 call automatically has geo tracing.

>The dispatcher's computer receives information from the telephone company about the physical address (for landlines) or geographic coordinates (for wireless) of the caller.

Wikipedia links https://propertyofthepeople.org/document-detail/?doc-id=2108... as proof that the E911 feature is used by the FBI to track phones.

Unfortunately, definitive capabilities and constraints of this kind of cellular technology is hard to come by.

Wait wait, so if I know the "secret" SMS format I can text someone's phone and get their coordinates back?

No, the SMS is initiated by the device upon calling emergency, not requested by the emergency service. The standard is called AML.

The format is not secret either, it's just binary encoded.

Ahh OK, well that just sounds reasonable.

I say """secret""" because the spec says that the format should not be published so people can't try to mess with the format, but the first link on Google shows the exact format.

The spec says:

> The AML SMS should not be seen by the caller and therefore should not appear in the SMS "sentbox" of the smartphone. This is to avoid any customer confusion and to avoid making the format of the message widely known. In addition, there is also a potential privacy concern in storing the location of an emergency call from the handset, which could be seen by others.

The AML SMS gets triggered by software on your smartphone when you dial an emergency number. You cannot use it to obtain someone else's location.

> This can be turned off, since implementation.

Not by users. The new thing is that Apple allows users to disable this feature. Hopefully they still detect emergency calls on the phone and enable it unconditionally for those.

yeah, there always was. It's a service code, like getting your imei. But it was a weird long one, and manufacturer dependent. Now UI switches are created for it apparantly. Can't find it anywhere on the internet though. I don't work there anymore, so can't look it up.

I believe they're talking about this feature (https://support.google.com/android/answer/9319337?sjid=18079...).

This is a system you can disable as a user, but it's not the on-modem feature discussed in the article.

How would the modem know your coordinates if the OS doesn't provide them?

> [...] The baseband implements other functionality such as Wi-Fi and GPS functionality [...] https://grapheneos.org/faq

It doesn't need to ask the OS, it can just get the coordinates and send them off.

Note sure: In my country exactly this feature is used by police & state enforcement to find locatin, because this "ping" message is not forwarded from the modem to the OS, so the OS is not aware of any of these messages

Do you use triangulation or GPS? EISEC in the UK only uses GPS, never triangulation.

Did you read the article or are you merely responding to the title? The article begins by acknowledging triangulation and then moving on to the point of the article. The article is about commands built into the UMTS and LTE specs for requesting GPS from the device. Your comment seems to be about everything but the main point of the article.

Did you read the complete comment?

> Next is a text to your phone number, which is intercepted by firmware and sends gps coords back.

Yes I saw that and also took it to mean the person didn't read the article. A text to your phone number? The article never mentions SMS. Heck I think the 2g/3g "feature" does not even require the phone to even have a SIM installed. This next sentence also seems to have been written without reading the article: "This can be turned off, since implementation."

The poster is giving information relevant only to the European Union ("112"). They are talking about https://en.wikipedia.org/wiki/Advanced_Mobile_Location I believe.

I don't think it indicates their article reading either way and wouldn't personally wager a guess. They are just adding their own personal experience to the conversation.

I have read the article. It's speculative and not a reveal of anything new. All is ITU spec and came down from there. So there is quite some overlap in emergency service short code regions. Another poster mentions 'ping', which is called pinprick for 112, which does work always, but requires authorization to be used. That I can confirm from experience.

The hacker news guidelines forbid you from suggesting someone has not read the article. Please do not participate in this forum with such conduct.

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