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Comment by fomine3 | Hacker News Reader

I surprised that US iPhone 13 still supports CDMA2000 EV-DO. Is it still worth to support?

That's a hard question to give a definitive answer to. In many ways, the answer is "no". However, as with most things in tech, there are always edge cases.

Sprint's network (which T-Mobile bought and is integrating into the T-Mobile network) never went fully VoLTE (voice over LTE) so if you had a phone that didn't support CDMA voice and you were on the Sprint network experience and you traveled to one of the rare areas where Sprint had coverage and T-Mobile didn't and there was no Sprint VoLTE available...

The thing about wireless is that there's always some vocal person who is getting better service from something that is worse for 99.9% of people. Of course, 99.9% means that you have one person out of every thousand and if you're a wireless carrier with over 100M customers, that means 100,000 people might be annoyed by progress.

In America where there's a huge rural population that expects all the amenities of big cities while the nearest neighbor is a quarter mile away, that can create some issues.

Plus, it's not just the 3 national carriers. There are also smaller carriers like US Cellular whose VoLTE support is newer, Shentel (who T-Mobile has more recently bought and whose network will get integrated probably in 2022/2023), etc. Those smaller carriers may not have upgraded all of their network yet. If you're European, the idea that we chopped up our licensing into hundreds of tiny license areas might sound weird (734 cellular market areas for the initial licenses, different sizes/shapes for subsequent licensing). VoLTE interoperability has been a bit of a nightmare and so CDMA has offered a certain amount of fallback for roaming (though that situation has mostly gotten cleared up, partly because T-Mobile didn't really have legacy compatibility to fall back on).

Finally, is it worth supporting? Ultimately, the support comes for free given that Qualcomm's X60 modem was going to support it whether Apple wanted that support or not. I think the iPhone 14 will support CDMA as well simply because Qualcomm's X65 modem will support it. I'm guessing that CDMA support will be dropped with the iPhone 15 when Apple moves to their own, in-house modems.

Verizon is shutting down their CDMA network at the end of 2022. By the time the iPhone 15 launches in fall 2023, CDMA will be quite dead. But legacy things stick around for a long time because even when it's not used by 99.9% of people, there's always some that will vocally complain about change and regulators don't like the idea of customer equipment being rendered useless.

Thanks. Licensing for tiny areas looks interesting.

> By the time the iPhone 15 launches in fall 2023, CDMA will be quite dead.

Perhaps in the US, but CDMA is used elsewhere too. In several countries in the recent past, fixed wireless CDMA operators (intended for home phone lines) started operating mobile handsets. Those places may not be on the upgrade path to LTE anytime soon, because of expense.

This is one of those "but actually" things that always happens (and why I can't give a straight answer and why I should have hedged that statement as well). The question was about the US and Apple and I responded about the US and Apple, but I should have know I'd get a "but actually" if I didn't hedge everything.

I don't know what country/network you're talking about, but it looks like Uzbekistan might be the only country that's valid for.

https://en.wikipedia.org/wiki/List_of_CDMA2000_networks

Beeline Armenia doesn't have a shutdown date, they also have GSM/UMTS/LTE service and their CDMA network is at 450MHz which the iPhone has never supported. MPT has an LTE service. That leaves Perfectum Mobile in Uzbekistan which looks like it's still heavy in CDMA. Uzmobile also seems to run CDMA at 450MHz, but again the iPhone never supported that. Going through Perfectum's website and looking at their suitable models feels like growing Verizon and Sprint's website from years past.

Yea, I should have hedged further and said "in the US and for Apple's purposes." Really though, I can only find Uzbekistan as an exception. And I could see Uzbekistan lingering on CDMA. Are there more?

I'm not even saying that old tech doesn't linger. Part of it is that CDMA wasn't popular in most of the world. GSM support will stick around longer because it was so popular. Most places that had CDMA networks have replaced them. CDMA kinda became a dead-end technology as Qualcomm's UMB evolution didn't happen - once Verizon chose LTE, there wasn't much of a point.

Honestly, it would have been cool if you'd added information about countries and networks where CDMA might stick around. I'd love interesting information - I literally went around looking for the information not included in your comment. Without that information, it just feels like "I know you were talking about Apple and the US, but actually..."

I'm having trouble finding things with searching tonight. But I think I know where to look to get the pointers I need... I'll see if I can dig up some examples tomorrow. Although, maybe I'll find that everyone has moved to LTE.

I was dealing with phone numbers for several years and there had been several networks which were CDMA for home phones only in otherwise GSM nations that started doing mobile phones. I suspect I can find some of the ones I managed to get added to libphonenumber when I was contributing to it. But, I don't know the frequencies, maybe they were at 450 and not iPhone accessible.

Well, I still can't find the references I'm looking for. So I'll accept that CDMA will be dead, and we can both be surprised if it survives a little bit longer.

CDMA2000 network (Au KDDI) is going to close but still operating in Japan, but iPhone 8 and successor for Japan model dropped support. iPhone works for LTE only on Au.

Thanks for the informative posts!

CDMA is the superior protocol afaict, unfortunately they wanted more in licensing fees at the beginning which stunted it. In any case a phone can support both in software.

This likely mirrors what happened when we moved from analog to digital. CDMA versions of phones like the Motorola v60 came with pull out antennas and were still capable of latching on to analog signals. It would drain the battery pretty quickly, but it worked.

Most people, most of the time, were riding digital signals and their phones never saw analog, but yet it was still there. A few things came into play:

1) The CDMA chipset in the phone had analog capability, so it was basically "free" to utilize.

2) Analog signal still worked well in rural/mountainous areas where it carried better.

3) It was still in active use with regional carriers they had roaming agreements with.

My guess is that similar conditions are why it is still in play in today's phones.

Lots of people buy their phones in the USA through relatives and then ship them to their own country. That might have prompted Apple to support stuff that they no longer need in the US?

Apple uses a Qualcomm baseband chip. They share the capabilities with other manufacturers, but Apple is working on their own baseband chip which they expect to ship in 2023.

But they don't have to implement CDMA2000 like other countries' models even though it uses Qualcomm chip.

The chipset the qcom modem they are using probably supports it. Would depend on the firmware and sometimes a grounded pin if it is on or not. Much like FM radio in many of these devices is 'there' but not turned on/wired up. For the new chipset that Apple is making I seriously doubt they would support that standard, esp if the big telcos are turning it off. But it would depend on what sort of contract they have with the telco.

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