Develop Bugs

Question for AT&T LTE users

So I get LTE but as soon as I get on a call signal goes to H and I cant use data/apps while on the call. Am I using the wrong APN settings, or wrong radio maybe? Any settings help would be great, or if you can confirm also. Thanks.

Mine nexus 6 did same thing. I'm not sure that the data still work or not but everytime I on call I see LTE Icon change to H like you said

It's one of 2 things.
Either VoLTE is not turned on on your device
Or ATT does not support VoLTE in your area.
First one is fixable. Second one is not.
Sent from my MI 5 using Tapatalk

TheDriller said:
It's one of 2 things.
Either VoLTE is not turned on on your device
Or ATT does not support VoLTE in your area.
First one is fixable. Second one is not.
Sent from my MI 5 using Tapatalk
Click to expand...
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AT&T doesn't support VoLTE on any phones that aren't sold by them.

StykerB said:
AT&T doesn't support VoLTE on any phones that aren't sold by them.
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Click to collapse
Then that would explain that I would think

LTE is data only, so when u go on a voice call it will got to hsdpa or 3g bc that is voice and data, so it is normal

Bradl79 said:
LTE is data only, so when u go on a voice call it will got to hsdpa or 3g bc that is voice and data, so it is normal
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Please don't spread information that's no longer the 100% truth. AT&T, Verizon, and (for a while now) T-Mobile offer calling over their LTE network, dubbed VoLTE (Voice over LTE). It allows voice packets to travel over the LTE network instead of legacy/3G and older networks.
The way the standard it set up, devices made more recently have software and hardware support for it, but as carriers have certification processes for their network, not all devices work cross-carrier. Most notably, iPhones (bleh) work cross-carrier because of the way their network configuration is provisioned (device identifies what network it's on, and downloads carrier configuration for that particular network). Some Android devices work cross-carrier (Nexus 6P and 5X), but the manufacturers of Android devices designing unlocked devices for some reason aren't certifying on AT&T, maybe because of cost or complexity.
Therefore, there are 3 main reasons VoLTE won't work on a device:
1) Not in a VoLTE area
2) VoLTE not enabled (this could encompass the option simply being disabled per the user)
3) VoLTE being restricted (AT&T restricting access because the device isn't certified, and/or the device not being capable)
Read up more on the requirements for AT&T (specifically) here:
http://att.com/hdvoice

balleron24z said:
Please don't spread information that's no longer the 100% truth. AT&T, Verizon, and (for a while now) T-Mobile offer calling over their LTE network, dubbed VoLTE (Voice over LTE). It allows voice packets to travel over the LTE network instead of legacy/3G and older networks.
The way the standard it set up, devices made more recently have software and hardware support for it, but as carriers have certification processes for their network, not all devices work cross-carrier. Most notably, iPhones (bleh) work cross-carrier because of the way their network configuration is provisioned (device identifies what network it's on, and downloads carrier configuration for that particular network). Some Android devices work cross-carrier (Nexus 6P and 5X), but the manufacturers of Android devices designing unlocked devices for some reason aren't certifying on AT&T, maybe because of cost or complexity.
Therefore, there are 3 main reasons VoLTE won't work on a device:
1) Not in a VoLTE area
2) VoLTE not enabled (this could encompass the option simply being disabled per the user)
3) VoLTE being restricted (AT&T restricting access because the device isn't certified, and/or the device not being capable)
Read up more on the requirements for AT&T (specifically) here:
http://att.com/hdvoice
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So how do you enable on the OP3 with AT&T?

SysAdmNj said:
So how do you enable on the OP3 with AT&T?
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You can't, only thing that would remotely make it work is if your imei was set up as a HDVoice supported phone in AT&T's system (s6, s7, note 5, note 7, iphone, etc). Though that likely won't work either since it'll try to provision the VoLTE and fail and yea.

AT&T does not use "Standard" VoLTE, so even if the phone supports it (like the OP3 does) and they were to allow the IMEI, it still wouldn't work. Phones have to have specific code from AT&T to do their HDVoice (according to their own customer service postings in their forums)

Getting voice over wi-fi on this phone? Anyone

Hello there, im trying to activate vowifi, i can activate volte fine but not vowifi, anyone got it activated and if you did how did you do it.
Sent from my SHARK MBU-H0 using Tapatalk

Are you in the USA? If so, that is the reason. Xiaomi phones are not whitelisted for wifi calling by ANY carrier here and this is not expected to change soon.
I am presuming you used short codes to turn on Volte successfully. The Wowfi code works also (phone is wifi calling capable) but its carrier disabled.
I bought a paid plan from FreeUP, an ATT MVNO, where you can use an app dialer to make outgoing wifi calls (and free unlimited international calls) but still no incoming wifi calls.
Same pricing as Mint Mobile.
(Fyi, even if you weren't using a global phone the only Android phones guaranteed to get wifi calling here are the ones the carriers here sell ... There are a few exceptions ... The newer pixels and a few others.)

Wifi calling greyed out (sprint to t-mobile)

Can anyone please explain the steps to enable wifi calling feature? i can toggle volte on/off but not wi-fi calling.
this was a sprint phone now on tmobile prepaid network.

Sprints firmware in conjunction with T-Mobile being T-Mobile does not permit both WiFi calling (or VOWiFi) or VoLTE (voice over 4g/lte).
T-Mobile made it known they will not permit support for this device and as of their plans for 2021, they plan to shut down 2g and 3g networks. Theoretically you'd have to upgrade your phone to a 5g T-Mobile certified phone. As per the merger with sprint, only select sprint based devices will be patched to work on T-Mobile (galaxy s20 ultra) being one of them.
To summarize, it won't work because sprint locked it and T-Mobile won't permit it. Gotta love the "un-carrier" for letting you "bring your own device". T-Mobile is more to blame. They don't want to support it. Hopefully we get a full root with a custom rom up that permits volte or VOWiFI otherwise this phone might be dead by 2021q1. Probably why it's <$300 on eBay right now.

i read some were able to get service codes to access hidden menu to update apn and mms settings by deleting sprint settings. would that fix all the issues?

toodyloo said:
i read some were able to get service codes to access hidden menu to update apn and mms settings by deleting sprint settings. would that fix all the issues?
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No that can't fix volte and vowifi

VoLTE/Wifi

Question about the impending doom of custom roms. I'm with T-Mobile and don't want to switch. So are texts included in this as well, or are only voice calls affected?

nola mike said:
Question about the impending doom of (LOS-based) custom roms. I'm with T-Mobile and don't want to switch. So are texts included in this as well, or are only voice calls affected?
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You are talking about this:
All U.S. V30/V3O+/V30S will need stock firmware, not LOS-based custom ROMs. When?
The first post is the most relevant. By page 3 the discussion had digressed into other areas.
At first, I thought only voice calls should be affected. (But... don't you need voice calls? Or do you have something like Google Voice? I have Google Voice but in the U.S. I still piggyback on my carrier's assigned phone number.)
(backstory, skip over this if you already know it)
4G LTE started out as "data only". Initially carriers had you temporarily dropping down to 3G (HSPA or CDMA) for voice calls until VoLTE (Voice Over LTE) was perfected.
But for V30 LOS custom ROMs -- which don't have VoLTE -- users still needed this temporary 3G access during phone calls. After the phone call is over, then you jump back to LTE (data only).
Now that 5G is being rolled out, U.S. carriers are killing off 3G to use those resources for 5G. AT&T is keeping 3G HSPA until February 2021, but initially it was reported Verizon and T-Mobile (Sprint) -- and their MVNOs -- are ending 3G in the next couple months. Verizon by January 1, 2020 and T-mobile allegedly in "January 2020" but they have set a specific day of the month that I've seen.
HOWEVER. HOWEVER...
T-Mobile may not be abruptly ending 3G HSPA in January 2021.
Instead T-Mobile says if your phone is not VoLTE capable by sometime in January 2021 it will be shut out of their network. This is not saying they are shutting down 3G HSPA in January 2021 -- just forcing all phones on T-mobile network to be VoLTE capable for WHEN they do shut down.
Hmmmm...
This potentially means you could still use custom ROMs a while longer if you somehow pass their VoLTE capable test? Because 3G HSPA may still be available for a while longer.
On the other hand if you do NOT pass their test, you can't use their network for texting either!
_____________
(Go to article below to see complete instructions and screenshots.)
How to find out if your T-Mobile phone has VoLTE support
T-Mobile will shut out all incompatible devices next year (2021).
Check the Settings app
If your phone is already activated on T-Mobile, you can check in your phone's settings if VoLTE is being used. Open the Settings app on your phone and go to the 'About phone' menu, then tap on 'SIM Status'. If you can't find it, try pressing the search button in the app and typing SIM.
Once you find the SIM Status option, tap it, and a popup should appear. If the voice network type is listed as LTE, you're good to go.
If your Settings app doesn't have that menu for whatever reason, try dialing *#*#4636#*#* in your Phone app. This will take you to a hidden diagnostics menu. Select 'Phone information,' then check if LTE is listed under Voice Network Type.

Ok, I had read some of this before, but not all. My phone passes those VoLTE capable tests. So does that mean that my phone is capable, but still not using VoLTE because it's on a custom rom? But that since it's capable, I'll still be able to use 3g network until 2021? And that once I lose voice, I lose texting as well?

If your carrier completely switches to 4G network then you can't use even text messages without Volte
Though using Google messages with RCS may allow you to get and send text messages with internet connectivity.

nola mike said:
Ok, I had read some of this before, but not all. My phone passes those VoLTE capable tests. So does that mean that my phone is capable, but still not using VoLTE because it's on a custom rom? But that since it's capable, I'll still be able to use 3g network until 2021? And that once I lose voice, I lose texting as well?
Click to expand...
Click to collapse
My best guess, but I'm not T-Mobile:
If your phone passes those tests then it probably won't be locked out of the T-Mobile network in January 2021. If so, then you will still be able to use LOS custom ROM for voice calls, for as long as T-Mobile keeps 3G towers running.
When they do shut off 3G -- may happen gradually, not all at once -- you will not be able to make phone calls on custom ROM without VoLTE, but should still be able to text.
Texts are data, and data-only LTE signal should still allow texting.

General For USA Users: I am getting wifi calling on an AT&T MVNO using the Note 9T

I thought I should mention that without rooting or any other hacks besides disabling carrier checking for Volte and VOwifi by entering the usual codes, I am actually getting wifi calling on FreeUP, an AT&T MVNO. Which probably means ATT and all its MVNOs get wifi calling on this model.
So far as I knew until now, ATT blacklists phones that it doesn't sell from using this particular calling feature. ( apart from iphones and Pixels bought directly from Google, because both of those manufacturers refused to let AT&T sell their phones otherwise).
I couldn't do wifi calling on any of my other Xiaomi phones (Mi Max 3, a Mi Max 2 and a Redmi Note 5 Whyred, all rooted), although I could get Volte to work using the shortcode for it. But wifi calling was supposedly blocked from the carrier's end and couldn't be enabled.
I expected to get the usual "no network" message when I tested wifi calling on the Note 9t by turning on airplane mode, then turning on wifi, but it just put the calls through.
(you could always get T-Mobile wifi calling to work on some Xiaomi phones, but TMO sometimes other had incompatibilities).
fyi, the codes, in case anyone reading this is new to Xiaomi:
Code to enable Volte: Dial * # * # 86583 # * # * using the default dialer -- the message has to say volte carrier check disabled for Volte to be enabled.
Code for Wifi calling: *#*#869434#*#* -- the message says says vowifi carrier check disabled for wifi calling to be enabled.
(but check the settings after using the codes because sometimes you still have to toggle them both on)
PS: This model is a pretty decent option for US buyers on a strict budget, as is the Poco M3 Pro.
The next step up if you need North American bands is the Mi 11 lite (about $100 more) and the Poco F3 ($150 more).