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I live in the US and have never heard of a phone that uses a different technology for emergency calls vs. normal calls. Why is this? Is it worldwide? As for th

I live in the US and have never heard of a phone that uses a different technology for emergency calls vs. normal calls. Why is this? Is it worldwide? As for the problem itself, I can understand government regulators not wanting to micro-manage the situation, but the carriers know what's on their networks, and a divide-and-conquer approach would seem capable of reducing the number of handsets to something manageable. For example, the Asus Rog phones are quite expensive, and official communication with Asus would seem enough to learn what they're capable of and what firmware upgrades may be coming. Done. In general, carriers shouldn't be blacklisting anything. If you're buying a non-carrier-branded phone, caveat emptor. But in Asus' case, at least, I expect they would try to make it right. I actually applaud the Australian government for being involved at all, as there was nary a peep from the US government and lots of people were forced to buy new phones who really didn't need them. The sin here seems to be throwing a "plan" together at the last minute.

gruez 2y ago
>I live in the US and have never heard of a phone that uses a different technology for emergency calls vs. normal calls. Why is this? Is it worldwide? It affects all telephone calls. Presumably people don't notice it because they use voip apps (eg. whatsapp) instead.
- rsynnott 2y ago
  Not necessarily, per the article. Some phones can make normal calls over VoLTE, but will fail to make emergency calls over it.
fragmede 2y ago
Apple has a feature to use satellites to relay calls to emergency services if you're out of cell range, I forget what Google did but they did something as well.
- cruffle_duffle 2y ago
  It isn’t calls, only texts. And you have to manually orient the phone so it is pointing at the satellite. You can’t just hold it like you normally do.
timv 2y ago
It's been more than a decade since I was involved with emergency services, but ~15 years ago there was a requirement (in Australia and elsewhere) that phones must be able to call emergency services from any available network even if the preferred carrier did not have service in that area. I assume that is still the case. That requirement forces phones to have some degree of special handling for emergency calls. It may have required (or been interpreted to require) that a phone make emergency calls over 3G if VoLTE was unavailable. I can imagine someone deciding that means "lets just use 3G for all emergency calls" because who ever expected a case where 4G was available and 3G was not.
- Dylan16807 2y ago
  > because who ever expected a case where 4G was available and 3G was not I'd expect that to be everyone that thought about it for more than a few seconds. Both because eventual replacement was obvious and because sometimes you only have partial coverage.
  - freshcupoftea 2y ago
    You may or may not be familiar with some of the use cases here in Australia. 3G coverage was more widespread and reliable for low bandwidth use cases, right up until the end. It was 4G that would have partial coverage, not 3G. 3G was often forced by IoT vendors, or routers using cellular for out of band management, due to its superior ability to penetrate through buildings. Same with ATMs, payment terminals, emergency telephones in lifts or out on the highways. People in regional areas would also force set their phones to 3G, to stop them flapping between a poor signal 4G network and the consistent, but slower, 3G network. Many DAS/Distributed Antenna Systems, essentially networks of antennas placed inisde buildings to extend cellular coverage indoors, are costly and must be approved on a per-operator basis. Some of the DAS solutions requirements I've seen to provide full coverage for Optus, Telstra and Vodafone in 4G only in a 30 story building or medium sized mall, wanted 18 full racks, 100 amp 3 phase power connectivity, 15kw minimum redudancy cooling capacity, 8 hours of battery backup for all racks and cooling, all located in the centre of the facility to minmize cable runs. As a result, high quality DAS systems don't exist in every large building or campus environment. Even in 2024, we see buildings nearing the end of construction before the developer bothers to consider an appropriate DAS system, and at that point they balk at the space and location requirements, and refuse to understand why a DAS can't just be installed in 4RU in a crammed comms room thats the size of a domestic bathroom.
daveoc64 2y ago
> I live in the US and have never heard of a phone that uses a different technology for emergency calls vs. normal calls. Why is this? Is it worldwide? In the GSM (2G) standard, and all of its successors, emergency calls are treated as a special case. Your phone does not simply place a regular call to 911 or other local emergency number. The pgone instead goes into a special mode where it can connect to any available carrier network to place the emergency call. It seems to be the case that some older phones didn't support placing an emergency call over VoLTE, so they just fell back to using 2G/3G when that was still available.
the_mitsuhiko 2y ago
> Why is this? Is it worldwide? It's part of the different mobile phone standards. Emergency calls get location information with them (AML), can be sent on other networks and without SIM card, they can be dialed on international short codes (eg: you can dial 112 in the US and 999 in the EU and it will connect regardless). There are many more differences.
- usr1106 2y ago
  Using different protocols for emergency call predates any caller location information. The main drivers at the time were network coverage (your SIM might have no coverage, but a network you are not allowed to roam for ordinary calls in has) and congestion (emergency calls can preempt ordinary calls).
kotaKat 2y ago
Fun thing, AT&T actually does the same level of phone whitelisting bullshit for VoLTE. https://www.att.com/scmsassets/support/wireless/devices-working-on-att-network.pdf https://www.att.com/scmsassets/support/wireless/devices-work...
- DCH3416 2y ago
  That's true. But generally you can still connect devices to the carrier network minus the ability to make voice calls.

gruez 2y ago

>I live in the US and have never heard of a phone that uses a different technology for emergency calls vs. normal calls. Why is this? Is it worldwide? It affects all telephone calls. Presumably people don't notice it because they use voip apps (eg. whatsapp) instead.

rsynnott 2y ago
Not necessarily, per the article. Some phones can make normal calls over VoLTE, but will fail to make emergency calls over it.

fragmede 2y ago

Apple has a feature to use satellites to relay calls to emergency services if you're out of cell range, I forget what Google did but they did something as well.

cruffle_duffle 2y ago
It isn’t calls, only texts. And you have to manually orient the phone so it is pointing at the satellite. You can’t just hold it like you normally do.

timv 2y ago

It's been more than a decade since I was involved with emergency services, but ~15 years ago there was a requirement (in Australia and elsewhere) that phones must be able to call emergency services from any available network even if the preferred carrier did not have service in that area. I assume that is still the case. That requirement forces phones to have some degree of special handling for emergency calls. It may have required (or been interpreted to require) that a phone make emergency calls over 3G if VoLTE was unavailable. I can imagine someone deciding that means "lets just use 3G for all emergency calls" because who ever expected a case where 4G was available and 3G was not.

Dylan16807 2y ago
> because who ever expected a case where 4G was available and 3G was not I'd expect that to be everyone that thought about it for more than a few seconds. Both because eventual replacement was obvious and because sometimes you only have partial coverage.
- freshcupoftea 2y ago
  You may or may not be familiar with some of the use cases here in Australia. 3G coverage was more widespread and reliable for low bandwidth use cases, right up until the end. It was 4G that would have partial coverage, not 3G. 3G was often forced by IoT vendors, or routers using cellular for out of band management, due to its superior ability to penetrate through buildings. Same with ATMs, payment terminals, emergency telephones in lifts or out on the highways. People in regional areas would also force set their phones to 3G, to stop them flapping between a poor signal 4G network and the consistent, but slower, 3G network. Many DAS/Distributed Antenna Systems, essentially networks of antennas placed inisde buildings to extend cellular coverage indoors, are costly and must be approved on a per-operator basis. Some of the DAS solutions requirements I've seen to provide full coverage for Optus, Telstra and Vodafone in 4G only in a 30 story building or medium sized mall, wanted 18 full racks, 100 amp 3 phase power connectivity, 15kw minimum redudancy cooling capacity, 8 hours of battery backup for all racks and cooling, all located in the centre of the facility to minmize cable runs. As a result, high quality DAS systems don't exist in every large building or campus environment. Even in 2024, we see buildings nearing the end of construction before the developer bothers to consider an appropriate DAS system, and at that point they balk at the space and location requirements, and refuse to understand why a DAS can't just be installed in 4RU in a crammed comms room thats the size of a domestic bathroom.

daveoc64 2y ago

> I live in the US and have never heard of a phone that uses a different technology for emergency calls vs. normal calls. Why is this? Is it worldwide? In the GSM (2G) standard, and all of its successors, emergency calls are treated as a special case. Your phone does not simply place a regular call to 911 or other local emergency number. The pgone instead goes into a special mode where it can connect to any available carrier network to place the emergency call. It seems to be the case that some older phones didn't support placing an emergency call over VoLTE, so they just fell back to using 2G/3G when that was still available.

the_mitsuhiko 2y ago

> Why is this? Is it worldwide? It's part of the different mobile phone standards. Emergency calls get location information with them (AML), can be sent on other networks and without SIM card, they can be dialed on international short codes (eg: you can dial 112 in the US and 999 in the EU and it will connect regardless). There are many more differences.

usr1106 2y ago
Using different protocols for emergency call predates any caller location information. The main drivers at the time were network coverage (your SIM might have no coverage, but a network you are not allowed to roam for ordinary calls in has) and congestion (emergency calls can preempt ordinary calls).

kotaKat 2y ago

Fun thing, AT&T actually does the same level of phone whitelisting bullshit for VoLTE. https://www.att.com/scmsassets/support/wireless/devices-working-on-att-network.pdf https://www.att.com/scmsassets/support/wireless/devices-work...

DCH3416 2y ago
That's true. But generally you can still connect devices to the carrier network minus the ability to make voice calls.