Turn on 4G HD Voice (VoLTE) on Vivo V9
- On main screen, select (Settings)
- Tap (Mobile network)
- Tap a button to turn on (VoLTE HD Call)
- When being in service area and VoLTE is shown on mobile, 4G HD Voice call or VoLTE service is ready to use
- What you should know about VoLTE usage
- must be U-SIM that supports 4G
- device supports VoLTE service
- service activation before using
- being in 4G HD Voice or VoLTE service area