Audio codec and VoLTE quality across networks

[DonDino]

What's the audio codec EE uses for VoLTE? Is that an industry-standard or does each network get to choose?

And when you call someone on another network and you're both using VoLTE, is the call quality still higher than 3G/GSM, i.e. do networks play well with VoLTE codec interoperability?

[Lee_H]

Hi @DonDino and welcome back to the Community.

This is something I will have to do some digging into.

Please let me find out.

Many thanks,

Lee

[Peter_C]

AMR-(S)WB will be the highest rate codec, much like CS over UMTS calling.

[DonDino]

I see. I've never tried AMR. 3G voice calls never sounded to me any better than the usual GSM or PSTN calls really. Is AMR-WB used for calls over 3G too then? 
For 4G, naive me would expect something like the quality of G722...

[Peter_C]

I just did an EE to VF call over 3G. EE was using the AMR-WB Codec. I have also had calls over AMR-NB. The former sounds very good, especially on same network calls.

I'd think that most/all the calls you make will be using an AMR variety, at least over 3G.

[DonDino]

Is there an app (or other way) I can use to tell which codec every 3G/4G call is using?

[Peter_C]

I use field test mode on my Samsung device, *#0011#. Not sure if it states the 4G codec on a VoLTE Samsung device though.