USA 3G sunset - swapping SIM could create headache

[Rick Law]

Arrgh...  In the USA, both T-Mobile and AT&T are beginning to sunset their 3G.

If you are still using 3G phone, don't swap SIM around...  I ran into this problem so I'm alerting others to expect possible problem with SIM swapping.

AT&T (my regular network, 3G shutdown is scheduled for Feb 2022)

I was expecting a call but my regular (3G) phone was on low-battery.  So, I put the SIM into another phone (4G/LTE) to catch the calls while my regular phone is being charged.  Re-inserting the SIM back to my now fully-charged 3G phone, everything looked normal, address bar is full and shows I am connected to AT&T network...  It looked so normal and typical I didn't even check - but it actually is not working.  I didn't even realize it was not working until I got an email: "...I've been calling you for a couple of days and your phone is not working..."  I checked: it can't receive and it can't make calls while externally everything looked normal.  It took a call to AT&T to re-enable my regular 3G phone.

T-Mobile (Business customer is scheduled for Dec 2021, unknown for consumer lines)

Since I didn't particularly like my AT&T's plan, I got a T-Mobile prepaid to check coverage in my area prior to AT&T shut down my 3G phone.  The T-Mobile's SIM worked just fine on my 4G/LTE phone.  I inserted the SIM into my regular 3G to copy some numbers then re-inserting it to the 4G/LTE phone.  Now it wont connect.  Just like before with AT&T, the phone shows full 5 bars and I am on the T-Mobile network, but it actually is not working.  After two calls to tech-support, I did got the T-Mobile SIM re-enabled on my 4G/LTE test phone.

Later, I thought about the reason why the 4G/LTE phone isn't working when they are merely shutting down 3G.  It may be my 4G/LTE phone doesn't support VoLTE and so it would be 3G voice-wise, may be.

So, if the SIM card is switched between phones, be mindful you may run into problems re-inserting back to originally working phone...

[firehopper]

my dad is on consumer cellular, and had 3g phone, his 3g phone was set to go dead on june 30th so he had to spend $35 to get a 4g version of the same flip phone.. was a pain in the arse to setup, as I hate t9 keyboards!

[Rick Law]

I expected that the phones will stop working sooner or later since their schedule was set, that was not the surprise.  What caught me off-guard was: pulling the SIM from my working (compliant till sometime in 2022) phone and insert it into another phone (compliant till sometime in 2022) stops the SIM from working again -- even when placed back into the phone that was working with the SIM moments ago.

This is different than what happened during the moved from 2G->3G.  I was swapping SIMs back and forth a lot while shopping for replacements phones.  The SIMs continue to function swapping back and forth during replacement shopping, and during migration.

That I cannot swap SIM back and forth added just a minor inconvenient.  That it caught me off-guard was the major annoyance.  The need to fight with robo-phone support multiple times first, then gained the opportunity to explain the issue to a real support person (who doesn't always get it), then needing to drive back to the phone store for a new SIM (which was unnecessary - on second failure, I caught on what was wrong and was able to get them to clear the SIM registration rather than driving back to the store for another SIM). 

No one likes fighting with Robo-Phone-Support.  That is why I wrote this post, part ranting, and part print out an "aviod this" sign.

[SteveyG]

3G needs some fairly legacy equipment which is probably running out of support. I'd be surprised if there is a large percentage of users that will be affected by this, other than maybe embedded systems or monitoring systems for alarms etc

What's with this recent use of the term "sunset" Strange one.

[rsjsouza]

My theory is that the transition between 2G to 3G was smoother/slower as the majority of people offered more resistance to throw away their older phones - nowadays these folks will be outliars in comparison with the overall customer base. Also, internet access probably comprises a much more significant portion of the phone activities itself, thus the move to a newer/faster packet technology would be more palatable.

But I agree the SIM dance is completely stupid.

What's with this recent use of the term "sunset" Strange one.

I have been hearing this word used in this sense for about twenty years. It is just one more way of saying a cold hard truth in a soft way so as to not hurt the feelings of whomever is on the other side of the conversation. 

This video comes to mind:

[SteveyG]

What's with this recent use of the term "sunset" Strange one.

I have been hearing this word used in this sense for about twenty years. It is just one more way of saying a cold hard truth in a soft way so as to not hurt the feelings of whomever is on the other side of the conversation. 

The sun rises again though the next day...  Surely phasing out or retiring is more applicable.

[themadhippy]

Are you sure it aint some sort of" security feature"  i recall having a similar issue years ago and it just  required a code provided with the sim being entered into the phone.

[SiliconWizard]

Are you sure it aint some sort of" security feature"  i recall having a similar issue years ago and it just  required a code provided with the sim being entered into the phone.

I would think that as well.

[tooki]

I think this also exemplifies a few things, including the complexity of SIM cards (which aren’t just dumb storage devices, nor even “just” encryption processors: they’re full application processors that run carrier applications), and that the network itself has complexity we don’t see.

[SiliconWizard]

I think this also exemplifies a few things, including the complexity of SIM cards (which aren’t just dumb storage devices, nor even “just” encryption processors: they’re full application processors that run carrier applications), and that the network itself has complexity we don’t see.

Speaking of which, there are now phones and networks that can operate without a physical SIM card. That's called eSIM. It's a virtual SIM card running on the processor, and it embeds much more information than traditional SIM cards as far as I've understood. eSIM is probably going to replace SIM cards completely.

[Rick Law]

In my opinion, eSIM rather missed the point of having a SIM at all.

Before this 4G era, the SIM is the portable "personality card" for your phone.  Inserting that card into a phone and that phone instantly becomes your phone.

Twice I dropped my phone in water.  I just wiped the SIM clean, put it in another phone and off I go - another phone with my phone number and contact list.  eSIM (non-portable) would remove that portability.

Decades ago (early 2G era) after my first business trip to Europe, I got off Verizon (CDMA, no SIM so it was eSIM of that era) and migrated to AT&T (2nd line T-Mobile) for the flexibility of GSM SIM-portability.  Subsequent trips I have my unlocked GSM phone.  I can use any GSM carrier's SIM on the same phone.  While overseas, I can also use a local-SIM and make local calls rather than via my USA-carrier.  Same physical phone with many personalities suitable for the occasion.

That said, 4G/LTE (to be precise, VoLTE, aka HD-Voice) will make cross-carrier portability difficult.  Unconfirmed but as I understand it: VoLTE on AT&T and T-Mobile are not the same.  So "carrier unlocked phone" may no longer ensure it will work on both AT&T and T-Mobile anymore.

[chickenHeadKnob]

What's with this recent use of the term "sunset" Strange one.

I have been hearing this word used in this sense for about twenty years. It is just one more way of saying a cold hard truth in a soft way so as to not hurt the feelings of whomever is on the other side of the conversation. 

The sun rises again though the next day...  Surely phasing out or retiring is more applicable.

I'm old, as in sixty+. I encountered "sunset clause" as legal jargon concerning contracts going back more than 40 years. It is nothing new and has nothing to do with fee-feels you may be having.

[tooki]

I think this also exemplifies a few things, including the complexity of SIM cards (which aren’t just dumb storage devices, nor even “just” encryption processors: they’re full application processors that run carrier applications), and that the network itself has complexity we don’t see.

Speaking of which, there are now phones and networks that can operate without a physical SIM card. That's called eSIM. It's a virtual SIM card running on the processor, and it embeds much more information than traditional SIM cards as far as I've understood. eSIM is probably going to replace SIM cards completely.

Yep, though as far as I know, it’s actually a dedicated embedded processor, since it is responsible for network security.

[tooki]

In my opinion, eSIM rather missed the point of having a SIM at all.

Before this 4G era, the SIM is the portable "personality card" for your phone.  Inserting that card into a phone and that phone instantly becomes your phone.

Well, it still is, both in the 4G and 5G eras, for the vast majority of users.

That said, 4G/LTE (to be precise, VoLTE, aka HD-Voice) will make cross-carrier portability difficult.  Unconfirmed but as I understand it: VoLTE on AT&T and T-Mobile are not the same.  So "carrier unlocked phone" may no longer ensure it will work on both AT&T and T-Mobile anymore.

Whoa there. You’re confounding multiple things. VoLTE ≠ HD Voice. Higher-bandwidth voice calling exists on 3G and even 2G networks, too. The specific implementation called “HD Voice” requires VoLTE, but not all VoLTE carriers and phones support it. And many carriers do not support high-bandwidth calls to other carriers, even if they use the same standard.

As for carrier locking: most carriers stopped that nonsense anyway, but HD voice support has NOTHING to do with this. The phones support what they support, the carriers support what they support, and the carriers’ peering support varies, so you end up with whatever the weakest link is for a given call.


EDIT: Closer inspection reveals that the "HD Voice" trademark specifically requires the use of the AMR-WB codec, but it can be implemented on any network type, not just VoLTE.

[Rick Law]

...
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That said, 4G/LTE (to be precise, VoLTE, aka HD-Voice) will make cross-carrier portability difficult.  Unconfirmed but as I understand it: VoLTE on AT&T and T-Mobile are not the same.  So "carrier unlocked phone" may no longer ensure it will work on both AT&T and T-Mobile anymore.

Whoa there. You’re confounding multiple things. VoLTE ≠ HD Voice. Higher-bandwidth voice calling exists on 3G and even 2G networks, too. The specific implementation called “HD Voice” requires VoLTE, but not all VoLTE carriers and phones support it. And many carriers do not support high-bandwidth calls to other carriers, even if they use the same standard.

As for carrier locking: most carriers stopped that nonsense anyway, but HD voice support has NOTHING to do with this. The phones support what they support, the carriers support what they support, and the carriers’ peering support varies, so you end up with whatever the weakest link is for a given call.

You are right, I should not have put it as "VoLTE aka HD Voice".

As to carrier-lock on phones, most US carriers are still locking phones, but they hardly offer the discounts they used to anymore.  With "HD voice" implementation differing from carrier to carrier, an unlocked phone would need to support most major carriers' implementation, otherwise the phone wont work.  That makes shopping for unlocked phone a bit more complicated: not just the right frequencies support, now one more factor that must be compatible.

[tooki]

As to carrier-lock on phones, most US carriers are still locking phones, but they hardly offer the discounts they used to anymore. 

Still?!? 

With "HD voice" implementation differing from carrier to carrier, an unlocked phone would need to support most major carriers' implementation, otherwise the phone wont work.  That makes shopping for unlocked phone a bit more complicated: not just the right frequencies support, now one more factor that must be compatible.

You're still confounding things. Again, "HD Voice" is not a generic descriptor, but the name of a specific standard. (Wiki:Wideband audio says: 'In cellular communication, "HD Voice" specifically refers to AMR-WB (G.722.2) in VoLTE. It is a trademark of GSMA, who runs a certification program around the logo.') There are no carrier-specific implementations. What is happening is the carriers beginning to require HD Voice support in the handsets. The differences in cutoff dates (and sloppiness in maintaining lists of devices that support it) is what's probably making you think it's carrier-specific.

[Rick Law]

As to carrier-lock on phones, most US carriers are still locking phones, but they hardly offer the discounts they used to anymore. 

Still?!? 

Yeah, AT&T and T-Mobile phones are not interchangeable unless you get the carrier unlocked kind.  Verizon is of course an island by itself.  The discount they offer is little to none, but the locking is still there.  The "discount" these days is installment - you can pay $X for Y months which adds up to pretty much the same as buying the phone outright.

...
You're still confounding things. Again, "HD Voice" is not a generic descriptor, but the name of a specific standard. (Wiki:Wideband audio says: 'In cellular communication, "HD Voice" specifically refers to AMR-WB (G.722.2) in VoLTE. It is a trademark of GSMA, who runs a certification program around the logo.') There are no carrier-specific implementations. What is happening is the carriers beginning to require HD Voice support in the handsets. The differences in cutoff dates (and sloppiness in maintaining lists of devices that support it) is what's probably making you think it's carrier-specific.

I probably am using the wrong descriptor.  To me, it doesn't matter what they call it - their voice implementation is different causing incompatibility that prevents even unlocked phone to work across carriers is the issue,  at least as reported in magazine/web-articles.

Granted, there are higher end phones (Apple, Samsung, etc.) that will work across carriers.  I am referring to the generic economic carrier-unlocked phones.

It is just a damn phone.  As long as someone can call me, and I can call someone, I am happy with it.  I could do that easily with 2G.  Get on ebay or whatever, order an unlocked phone, insert my SIM in it and off I go.

After days of research, I gave up the hunt - I'm waiting for a flip-phone shipment from AT&T, and separate flip-phone for T-Mobile is also en-route.  I may yet get them unlocked to try, but right now I am just testing coverage and decide which carrier I want to go with.  Now that I am not doing international business travel anymore, lacking the ability to use a local SIM is not a critical issue for me anymore.  Having experienced at home I had only T-Mobile, and at work I had only AT&T/Cingular; I know they both have grown a lot since but I still like to test their coverage within the area I frequent prior to deciding which one I want to go with. 

[AntiProtonBoy]

What's with this recent use of the term "sunset" Strange one.

I have been hearing this word used in this sense for about twenty years. It is just one more way of saying a cold hard truth in a soft way so as to not hurt the feelings of whomever is on the other side of the conversation. 

I think industry just love to use wanky catch phrases like that, just like "the chickens have come home to roost".

[retiredfeline]

Sunset clause is a phrase that has been in legal use for decades, and chickens coming home to roost is even older, from the time of Chaucer.

Not all terms are invented by marketing. If there is a phrase circulating that captures the concept succinctly then people will adopt it.

[ThermallyFrigid]

In my opinion, eSIM rather missed the point of having a SIM at all.

Before this 4G era, the SIM is the portable "personality card" for your phone.  Inserting that card into a phone and that phone instantly becomes your phone.

Twice I dropped my phone in water.  I just wiped the SIM clean, put it in another phone and off I go - another phone with my phone number and contact list.  eSIM (non-portable) would remove that portability.

Decades ago (early 2G era) after my first business trip to Europe, I got off Verizon (CDMA, no SIM so it was eSIM of that era) and migrated to AT&T (2nd line T-Mobile) for the flexibility of GSM SIM-portability.  Subsequent trips I have my unlocked GSM phone.  I can use any GSM carrier's SIM on the same phone.  While overseas, I can also use a local-SIM and make local calls rather than via my USA-carrier.  Same physical phone with many personalities suitable for the occasion.

That said, 4G/LTE (to be precise, VoLTE, aka HD-Voice) will make cross-carrier portability difficult.  Unconfirmed but as I understand it: VoLTE on AT&T and T-Mobile are not the same.  So "carrier unlocked phone" may no longer ensure it will work on both AT&T and T-Mobile anymore.

I was told that......
The ability to track you and every use of the phone has become a priority far more important than user convenience.  The Chinese people have absolutely zero expectation of privacy so there it's a non issue.

Was that incorrect?

[SiliconWizard]

In my opinion, eSIM rather missed the point of having a SIM at all.

Before this 4G era, the SIM is the portable "personality card" for your phone.  Inserting that card into a phone and that phone instantly becomes your phone.

I agree. But it gives more control to the operators, making you completely dependent on them for portability.

The customer was once king. These days are long gone.

[Rick Law]

Yeah, the good old days of just a simple phone are gone...  I just want a simple voice-only phone, but even the new flip phones has all that damn junk loaded on it, none for my benefit but theirs...

I really do miss those good old days.

[tooki]

In my opinion, eSIM rather missed the point of having a SIM at all.

Before this 4G era, the SIM is the portable "personality card" for your phone.  Inserting that card into a phone and that phone instantly becomes your phone.

I agree. But it gives more control to the operators, making you completely dependent on them for portability.

The customer was once king. These days are long gone.

LOL what? That’s the exact opposite of how things went. We used to be far MORE carrier-dependent than we are now.

Have you forgotten that for most of the history of telephony in most places, there was a single national monopolist for phone service? The customer was certainly not “king”.

[Rick Law]

SIM vs eSIM (or no SIM) really is just half the equation.  SIM doesn't free the customer from carrier, however, it unlink the lock between the carrier and the phone hardware.  So one is tied to the carrier up-to but excluding the end point.

If I have carrier X's SIM, I can use that on any compatible phone.  So my phone choice is carrier independent.  However, eSIM (or no SIM) likely ties the phone hardware to the carrier and a specific phone.  So one is tied to the carrier up-to and including the end point.

I said "...likely ties the phone..." above because one can of course implement eSIM in such a way that it can be moved between phones, but I doubt that would be the typical implementation.  Besides, you have to "export" that eSIM first before you can use it on a different phone.  If the reason is because your phone took a bath at the beach and wont power up, you are as lost as no-SIM.

[tooki]

I don’t disagree that the eSIM is less portable than a hardware SIM. But I was responding to the preposterous claim that “the customer was once king”.

Have you guys all forgotten what the pre-iPhone days of mobile carriers were like, in particular in USA? ATT (the old one on TDMA), Sprint and Verizon used nearly-proprietary hardware. (And remember Nextel, which literally used an entire proprietary mobile network standard?) Cingular and T-Mo were already GSM but locked down everything. Every carrier loaded custom firmware onto their devices to plaster their proprietary BS apps everywhere, defacing even excellent hardware. (I had an otherwise lovely Sony-Ericsson phone that Cingular had stolen two useful buttons from, hard-mapping them to useless carrier apps instead of the useful functions those buttons normally had.)

Then Apple came along and convinced Cingular to agree to have zero control over the handset software and apps. I cannot overstate enough how much of a game changer this was. And then all the other carriers had to agree to the same thing because they wanted to sell the iPhone, too. The entire smartphone industry benefited immensely from Apple dedtroying the carriers’ stronghold on handset software. Apple is the company that turned the carriers into the “dumb pipes” they should be.