[HTC 10 Questions & Answers] Haldi4803:
Hi,

As my Provider does support WiFi Calling for the Samsung S6, S7 and iPhones i tought it should somehow be possible to get it working on my HTC10.

With the newest 1.98.709.5 Update the ROM itself should fully support VoLTE and WiFi-Calling, but it's a TW branded ROM so it obviously only supports Taiwan Carriers.

So there are two options:

A: Fake/Spoof my phone into thinking it's connected to a Taiwan Carrier.

B: Modify the System/App that it works with my Carrier.

While searching the Web i mostly found DAU webpages that show the setting option to activate WiFi calling ~.~

Only for the Z2 there seems to be a modification to get VoLTE and WiFi calling working. But they have way more stuff to edit and my carrier does not support VoLTE anyway.

So after stooping around the system for a while i couldn't find anything in build.prop related to WiFi calling.

But i found these few APKs in /system/priv-app that might be related.

CustomizationSettingsProvider.apk

SettingsProvider.apk

WFCWifiCall.apk

I tried to decompile them with APKtool and take a closer look.

The thing is... i suck at stuff like that. I have literally no idea about android app development.

.smali ? wtf is that?

In the /res/xml/ of WFCWifiCall.apk i found an ims_qanda.xml and ims_qanda_metropcs.xml

The MetroPCS simply has MetroPCS instead of T-Mobile

<?xml version="1.0" encoding="utf-8"?>
<IMSQandA>
<Question>What is Wi-Fi Calling?</Question>
<Answer>Wi-Fi Calling lets you make and receive voice calls and text/multimedia messages over Wi-Fi when your phone is connected to a Wi-Fi network and registered with the T-Mobile network for Wi-Fi Calling.</Answer>
<Question>How do I enable Wi-Fi?</Question>
<Answer>To enable Wi-Fi, use the wireless control section of your Android settings menu.</Answer>
<Question>How do I enable Wi-Fi Calling?</Question>
<Answer>By default, your phone is enabled for Wi-Fi Calling as soon as you enable the Wi-Fi radio. Wi-Fi Calling can be controlled from the Wi-Fi Calling Settings.</Answer>
<Question>How do I know when I am using Wi-Fi for my calls?</Question>
<Answer>When your phone associates with a Wi-Fi network, it will automatically try to register with the T-Mobile network for Wi-Fi Calling. Once the registration has successfully completed you will see the Wi-Fi Calling icon in the Status Bar. You will also see the Wi-Fi Calling icon displayed in the dialer (in place of your regular calling icon) and you will briefly see a message at the top of the screen saying, "Calls will be made over Wi-Fi."</Answer>
<Question>Will calls or SMS/MMS over Wi-Fi be charged differently than my cellular calls?</Question>
<Answer>The primary benefit of Wi-Fi Calling is to increase your coverage in locations with Wi-Fi. Calls and messages made over Wi-Fi will be charged like cellular calls for certain plans.</Answer>
<Question>What happens if I lose Wi-Fi coverage?</Question>
<Answer>When the handset loses Wi-Fi coverage, any active calls will drop and the phone will connect to the cellular network if possible. You will receive a prompt if your call drops due to a loss of Wi-Fi coverage.</Answer>
</IMSQandA>

But i'm not even sure if that's the right file to look at.... TW phone and it goes on about American Proviers? mhkay...

So in short, i have no damn idea.

I'll take any hint, thanks.