I was hoping to get back here before the thread closed.
I mentioned before that I had no internet from 2014 to late 2020. As a result all of my phones used just cellular data, so never had a chance to do WiFi related stuff (other than occasional tethering). After the last conversions and me not knowing much I figured WiFi calling just didn’t work on my phones with custom ROMs or maybe non-certified devices. Not sure.
Fast forward to a few days ago. Went to the T-Mobile website to pay my bill. Decided to check out their help and support section, just because. Under WiFi Calling there was mention of needing an e911 address associated to a device. That was the case for my old daily driver but not for the other devices. So I did that though not sure it’s really mandatory. Figured it was now time to really figure things out.
- OnePlus 8T+5G, Android 11, Carbon ROM. (A T-Mobile purchased device - KB2007 kona. “Rebranded” to KB2003 kebab, allowing for flashing ROMs and recoveries). Carrier T-Mobile.
- Moto G5 Plus potter, Android 7 Nougat, LineageOS 14.1 Unofficial. Carrier T-Mobile. Daily driver. Multiboot with three other ROMs so also tested Tesla and Carbon.
- Essential PH-1 mata, Android 9 Pie, /e/OS. Carrier Mint Mobile.
- Teracube 2e, Android 11, /e/OS. Carrier T-Mobile.
Last time I tried WiFi calling I thought it was working. In the feature’s options I had WiFi preferred for calls. When a call went out I thought it was good. Read recently that if you have a strong cellular connection then calls would still go through that and not WiFi.
Tried the tip of turning on airplane mode then turning on WiFi (LOL, didn’t know that was possible. Always thought airplane mode was an all or nothing thing). In this mode the OP8T clearly had WiFI Calling working. Outgoing and incoming calls were so noted.
Checking the phone hidden settings (still recommend using the Network app for quick access) I see that the Data Network Type is IWLAN and the the Mobile Radio Power was still on. On the other devices, going into airplane mode turns that off.
Data Network Type is not to be confused with Preferred Network Type.
The mata is the only other phone that shows IWLAN but any attempts at making calls quickly fail because the radio power is off. Turning it on immediately changes the Data Network Type to LTE. Plus the IMS Status is not registered with features unavailable. On the potter and T2e the DTN is unknown when the radio power is off, LTE when turned on.
Interestingly, when DTN is IWLAN, the Current Network is shown as T-Mobile. Once radio power is turned on it changes to Mint.
On a side note more applicable to the Samsung S9 VoLTE thread @Taurus mentioned that when dialing out, if the signal icon changes to H or H+ then VoLTE is not working. That was the case on the mata. It uses Mint Mobile. I took a look at its APN. Near the bottom is MVNO Type. Knowing nothing about that setting I checked the choices and saw IMSI. Selected it and saved. Lo and Behold, my IMS Status was now registered and Voice over LTE was available. Tested outgoing calls and they no longer changed to H or H+. Good.
Back to WiFI Calling testing. Knowing the airplane mode on / wifi on method won’t work I turned off mobile data and turned on wifi. The switching around made the IMS status unregistered but toggling off WiFi Calling, waiting a few seconds, then turn back on re-registered it. VoWiFI is shown as available but can’t seem to dial out. The dialer clearly shows it trying a wifi call but after awhile it fails.
After constantly playing around I seem to have lost the ability to get IMS registered again. No VoLTE. Wonder if it’s because I add all my networking stuff back after the initial tests. I’ll see later.
Also noticed on the mata and potter, if I change the preferred network type to LTE only and there’s no VoLTE, it is not possible to make any calls as the lesser protocols are not available.
For the potter, tested things on the three ROMs. No VoLTE or VoWiFI. T-Mobile IMEI check page says the device is fully capable yet T-Mobile has sent me emails telling me otherwise for that phone number.
Teracube 2e. Not much to say. No WiFi calling. Only feature unavailable under IMS status.
Wonder if SIM age matters in some cases. SIM used in the Moto may be my original going back to 2013/2014 I think. From Samsung Galaxy Light running Jellybean, to several LG G3’s running KitKat thru Nougat, then to the potter.
SIM in the Teracube is from my Axon 7. Originally purchased as a replacement for a bricked G3. Android 6 / Marshmallow era.
A call to T-Mobile maybe and see if there’s some updating needed or if I’m out of luck.
tl;dr this mess of a rambling post. Four devices, three Android versions, six ROMs. Only the OnePlus has Voice over WiFi it seems. Not good.
Don’t mind the ugly contact photos. Have no idea who that guy is.