Hi from Germany, just found that thread via google as i searched for a way to get the one m7 working with volte, cuz i think htc would not update the one m7 with any features like that. Even the one m8 didn't had a update, and here in germany the carriers support voLTE. So i didn't rooted my one m7 till now. Isn't the easiest think with stock android 5. Just saw that the same xml file is also in the m7. So my question is, has anyone of you an one m7 wich is rooted and could test if the option appears in the Settings? Would help me a lot, if it does i would root my phone and try it out if it works on the vodafone LTE in germany. Its so bad that HTC didn't push updates till now, when the other brands already support it. Thanks for answering and sorry if i am here on the wrong Thread because i am in the one m8 forum.
But, then again, we are on US Verizon and we have to wait for Verizon to enable it per device. I have a sneaky feeling that our carrier is tracking IMEI's, associating it to the device ID's, and determining which ones to allow VoLTE.
I have no idea how Germany does it. Your carrier may allow it for all carriers. It may work for you if the carrier has already enabled it. For example, Verizon was slow to release the Nexus 6 but they had already added it to their VoLTE list. I was able to flash 5.1 to a Sprint Nexus 6 and use Verizon VoLTE.
okay thought even when the carrier don't allow it, u can toggle it in the menu and then get a fail message. I will try, maybe the one m7 is also blocked and not supporter so it won't work, or the phone app isn't ready for that and the switches are just fragments, of software for other models.