I have a Huawei Y6s JAT-LX3 which appears to have been sold as a G3.5 model. Vodafone NZ (now known as One NZ) are switching off G3 at the end of this year. They say if your phone can do VoLTE to get G4 voice calling, then enable it following the maker's instructions. The downloaded English manual for this phone gives clear instructions, but the Enable VoLTE button does not show on screen. I have had 4 OTA firmware updates since buying this phone, so I can only assume the NZ rom has this...Read more