On Xiaomi phones, you can enable VoLTE using this command, just key in a the dial pad and dial *#*#86583#*#*
All three phones Huawei Nova 3, Xiaomi Mimax 2 and Samsung Galaxy Note 8 supports VoLTE.
Although VoLTE is enabled, tester is unable to make any voice calls. Making calls to the TPG numbers from other telco or fixed line failed too.
Update: TPG to TPG calls work but any outgoing or incoming calls from other telcos don’t. TPG to TPG voice calls work on Huawei Nova 3i and Xiaomi MiMax2., Redmi 5 plus. Tester can’t get it to work on the Samsung Galaxy Note 8 and Oppo R17Pro.
Here are a list of phone models that work with TPG’s VoLTE.
Xiaomi Redmi 5 Plus
Huawei Nova 3i
Xiaomi MiMax 2
Xiaomi Redmi Note 4 Qualcomm (regional setting to Malaysia)
Xiaomi Redmi Note 5
Xiaomi Mi A1 (Do not upgrade to Android PIE)
Xiaomi Mi A2 Lite (Do not upgrade to Android PIE)
Xiaomi Pocophone F1
Update on 8 Jan 2018: Voice calls to Fixed Line e.g. banks work but calling home fixed line doesn’t. Calling to mobile numbers do not work at this moment. e.g 62255225 (CITIBANK), 65427788 (Weather Forecast).. Calling to MyRepublic fixed line works.
The following devices do not work with VoLTE as yet.
Pixel 3 / 3 XL
Apple iPhone (all series)
Huawei Mate 10
Huawei Mate 9
LG G7+ ThinQ