Note:Confirm with your phone service carrier if your location, your account and your phone model can support VoLTE service. Also, the numbers you are calling need to meet these requirements so you can use VoLTE service.
Some carriers support VoLTE only in certain cities or area codes. Contact your carrier to inquire about your area and account.
* Please notice that this function is only available in some models.
Please follow the steps below to confirm if VoLTE function is enabled on your phone:
1. Go to [Settings] > [More]
2. Choose [Cellular networks]
3. Enable [Enhanced 4G LTE Mode] to use VoLTE service.