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Apple's Dual-SIM Tech Ruins Verizon Coverage (pcmag.com)
Apple's new dual-SIM function, which lets iPhone XS, XS Max, and XR owners use two cellular subscriptions at once, will come to new phones today. But the current implementation will have a huge negative impact on Verizon subscribers who choose to use dual-SIM in the US, PCMag reported Tuesday, citing engineers who have seen early builds of the software. From the report: Dual-SIM, a popular feature in the rest of the world, is largely unknown in the US. Generally, it's used for three things: roaming internationally, where you get a foreign SIM and also keep your local number; having home and work lines on one phone; or trying out multiple domestic services to see which one is better. Apple's dual-SIM relies on one physical SIM and an "electronic SIM" or eSIM, which is activated from a menu or an app. AT&T, T-Mobile, and Verizon promised eSIM support at launch, but neither Verizon nor T-Mobile will support the eSIM right now. T-Mobile is working on it and will support eSIM when its software is ready, the carrier told me.
[...] The problem comes when a physical Verizon SIM is pushed into the "secondary" position while the phone is in the US. Under the current software build, that kicks the Verizon connection down to 2G CDMA, an old network with significantly less coverage than the current LTE network. The old network also has no MMS support, and certainly wouldn't work for FaceTime. So Verizon customers may find they have perfectly good coverage with their SIM in "primary" position, but no signal and fewer features with the SIM in "secondary." When I asked Verizon about the CDMA network, the company said that 30 percent of its cell sites were now LTE-only, so there would be a definite coverage hit.
[...] The problem comes when a physical Verizon SIM is pushed into the "secondary" position while the phone is in the US. Under the current software build, that kicks the Verizon connection down to 2G CDMA, an old network with significantly less coverage than the current LTE network. The old network also has no MMS support, and certainly wouldn't work for FaceTime. So Verizon customers may find they have perfectly good coverage with their SIM in "primary" position, but no signal and fewer features with the SIM in "secondary." When I asked Verizon about the CDMA network, the company said that 30 percent of its cell sites were now LTE-only, so there would be a definite coverage hit.
How is this Apple's fault? This is 100% on Verizon. Verizon controls what network a device can connect to. MAYBE Apple's eSIM shit is wonky in some way, but since it works on 2G, that means Verizon can at least get the basic details from the SIM and talk to the device. That means they can associate it with a customer account and can put it on the proper network.
This is Verizon's fault.
That summary sounds like the problem is with Verizon, not with Apple.
Still a nope. The secondary position only switches to that band because of the US network. Reread the article and you'll note that pushing the SIM into secondary outside of the US works just fine. The thing to note is that when you push a SIM into the secondary position, the device will attempt to ask the cell service to allow only inbound calls, since all outbound calls are done via the primary. Apparently, US cell networks explode in a puff of "WAAAA??" when asked to do this, and just go lowest common denominator in the confusion.
In short, asking a US carrier to provide an "inbound only" line is witchcraft and the iPhone just deals with the mass pandemonium as best as can be expected.
Apple is rolling out unfinished technology.
Not unfinished on Apple's side though. Works fine in Europe.
All that is unfinished is the U.S. carrier side, where carriers are dragging feet. I think Apple has done the right thing, which is to release it as is and let carriers start to take support calls based on shoddy or incomplete network support for what is a standard feature is many other countries...
"There is more worth loving than we have strength to love." - Brian Jay Stanley
It's truly ludicrous that outside of North America, dual SIM phones are the norm, whereas in NA, it is impossible to buy a phone from a carrier that is dual SIM (at least that's the case in Canada). That kind of nonsense is the result of having oligopolies. I voted with my wallet and bought a dual SIM Xiaomi from a third party. Will likely do so next time I need a phone as well.