Get Unlimited Talk, Text, & Data for $40/mo. when you sign up for AutoPay. Plus, Mexico & Canada included!
balst01's profile

Teacher

 • 

106 Messages

Saturday, April 9th, 2022 4:45 PM

Cannot Make or receive calls on non AT&T 4G phone. 3G sunset is to blame.

Re-posting this since the other threads all have "Accepted solutions". In my opinion "buy a new phone" is not an acceptable solution, and I will not be marking it as such. AT&T need to fix this issue.

About 2 days ago, my phone stopped working for any voice calls. I have a Galaxy S10+ and I just upgraded to One UI 4.1, and I think this may have been the start of the issue. If you have a non-AT&T Galaxy, don't take the upgrade, it will kill your ability to make phone calls.

To help others out, so far, I have tried the following and it *DOES NOT* fix the issue:

  • Restart the phone (several time). Of course this was never going to fix it
  • Call AT&T support and ask them to reset my wireless service, no help
  • Went in to the AT&T store and asked them to replace my SIM with a new one. Makes no difference at all
  • Did a factory reset on my phone. Doesn't help
  • Manually set the wireless settings according the the AT&T table in "Access point names" settings. Makes no difference

Just to be sure, I placed my SIM in my wife's phone (identical phone but she has not taken the One UI 4.1 upgrade), and her SIM in mine. My SIM works fine with my number in her phone. Her SIM fails with her number in my phone.

Conclusion: It's the phone, not the SIM, and even a factory reset won't help.

I think I know what is causing the problem; maybe one of the AT&T techs on this forum can confirm. AT&T have stated elsewhere that after the 3G sunset, having HD voice is a requirement to make calls, so there appear to be 2 requirements of phones:

  1. Phone must be capable of 4G; this gets you service so you can use 4G data and send/receive text message via SMS
  2. Phone must be capable of HD Voice; this allows you to make and receive phone calls

If you have 1. but not 2. you can't use your phone to make calls, but everything else would appear to work fine.

The thing is, a Galaxy S10+ should be capable of HD Voice calling, but I think my upgrade to One UI 4.1 may have broken it. In addition, I have a foreign S10+ with the Samsung branded processors on-board (different to the U.S. models). 

Any of the AT&T techs care to comment?

BTW: "Buy a new phone" is *NOT* an acceptable solution, please fix it.

Teacher

 • 

106 Messages

1 year ago

OK, I got through to someone who helped, no guarantees, the this is correct, but here's the story.

WiFi texting is a different beast to WiFi calling. AT&T do support both WiFi calling and WiFi texting on certain models of phone. They have made a conscious decision to record when a user uses WiFi calling, and because of that they can offer features like free WiFi calling when roaming in another country. They do not record when a user uses WiFi texting, and their system cannot tell difference between a WiFi text and an non-WiFi text after the fact.

The multi-SIM system that is baked into Android (and iPhone BTW) allows the user to choose a primary SIM for any of calling, texting, and data individually. Data is only delivered by the designated default SIM, and it affects all apps. For calling and text, it is down the the system default handler (app) for each of those mediums to determine what to do. Most Android phones allow you to switch the default app for calling and texting, but you can only choose one at a time, and how the incoming media is treated is down to the app

Most Android calling apps will recognize that there are multiple SIMs, and can receive calls from both, and allow the user to choose which one to use for each individual outgoing call, the Samsung dialer (the default calling app on the Galaxy) does support dual SIM correctly, can dan do this; this is exactly what I see when running dual SIM.

There are no texting apps which correctly support dual SIM that can be used as the default texting app on Android. Both the Samsung messages app and the Google messages app have the same behavior, they will deliver text messages only from the SIM designated as the default SIM for texting, however, if a message comes in from the other SIM, they will notify the user that it happened, without actually delivering the message. In order for the message to be delivered, the SIM needs to be switched to the default SIM for messaging.

Back to AT&T. Since they do not record whether a text message is delivered via WiFi, they will charge the user based only on the information they have. If, at the time of delivery, the SIM is designated as roaming in a location that does not support free roaming according to the user's plan, then the user will be charged the standard roaming rate for delivery of that message, regardless of how it was delivered. Text message delivery is currently covered by the standard international daily rate, although that can change at any time.

AT&T are not inclined to fix this issue and record WiFi texts separately (allowing them to offer free international WiFi texting) because there are several other applications which can handle texting with full end-to-end encryption via the data network (e.g. WhatsApp). If you want free texting while roaming, then use another texting medium.

Seems like a reasonable statement at face-value, but I don't think I'll be able to persuade my Gran to use WhatsApp. It is what it is, and I don't think we'll get any traction on this with AT&T (or any other carrier).

Teacher

 • 

106 Messages

1 year ago

BTW: This is probably obvious, but Telstra (and it turns out most Australian carriers) *do* record when a text message is delivered via WiFi, and therefore can (and do) offer free WiFi texting while roaming in another country. I guess it's all about market forces; one carrier decides to do it in Australia, and they all follow suit. Obviously, none of the carriers in the U.S. see this as a valuable feature, so it doesn't happen.

Teacher

 • 

106 Messages

1 year ago

Got the upgrade to Android 13 (One UI 5) last week, and I just noticed a new feature on the Google Messages app. Each time I send a text message now, there's a small toggle to the right of the typing box which lets me switch SIM dynamically for each message. I can dynamically choose what SIM to use for each message, just like the Phone dialer app for phone calls.

Finally, the software is starting to catch up with the hardware; but there is a catch, at least on the Galaxy phones. If the message is not sent over RCS (i.e. it's an old SMS message) then after I send the message, it will not actually be delivered until I switch the default SIM for messaging in the main system settings to the correct SIM, so it sends as the other number, but nothing happens until the messaging SIM is switched. Given what I see in the Google Messages app, I suspect the experience might be different on a Pixel phone, where it may allow messages from both SIMs simultaneously, without having to switch the default in the system settings.

Of course, either way, if you send or receive a message using an AT&T SIM, and you are roaming outside the free roaming zone, they will still charge you for the privilege :(   ...but it's getting better, maybe the carriers will catch up eventually.

(edited)

Not finding what you're looking for?
New to AT&T Community?
New to the AT&T Community? Start by visiting the Community How-To.
New to the AT&T Community?
Visit the Community How-To.