With Jio 4G SIM in your device, you must have noticed an extra HD or VoLTE icon besides network bars in the notification panel. This icon is very important for your voice service with Jio 4G SIM card.
Unlike traditional network operators where voice calls were made based over network bar (radio), voice call in Jio 4G is dependent on VoLTE or HD. This is a separate entity in network architecture other than radio access.
So in short for Jio 4G:
For other 2G/3G/4G operators, normally people look for network bars and if its available they go for voice call.
But for Jio 4G you will have to look for both network bars and HD or VoLTE icon to go forward with the voice call.
When registered on HD or VoLTE, user can experience est in class voice and video calls to other Jio 4G users.
The audio clarity is very good as the voice transmission takes place over IP network.
Broadly speaking, when you power up your phone:
Now some device do not support VoLTE from hardware itself and so they will have to use “JioVoice app” for voice services.
When this app is installed you will have a JioVoice phone dialer similar to your default phone dialer app.
There will be no HD or VoLTE icon in notification bar when using “JioVoice app” but you can still make or receive calls from this app.
In short you will have to replace your default phone dialer app to “JioVoice app”.
Note: JioVoice app works only when Jio 4G SIM card is inserted in you phone.