Get VoLTE working

• /e/ version:
• Device model:
• Reproducible with the last /e/ version:
• Reproducible with LineageOS:

Summary

We would like to have the VoLTE working.

This improvement concerns

• UI
• Behavior
• Privacy

Description

What is the current behavior?

During a call on LTE or LTE+ network, the network switches on 3G. It's because the VoLTE is not working.

What is the improved behavior?

During a call on LTE or LTE+ network, the network is still on LTE/LTE+.

What does it bring?

It will allow to use /e/ on carrier that provides only VoLTE.

Examples

Use the phone on USA carrier especially, or any other carrier in the world which works only with VoLTE.

Validation

Have the device connected to LTE network, call someone, and the device must stay connected to the LTE network and not switch to 3G.

FYI @gael @AlexandreRouxDanzi