Search | Sailfish OS | Running | PineTime | All Posts

VoLTE on Sailfish OS / Xperia 10 II

July 15, 2022 — Nico Cartron

It's finally here, at least in Beta! Let's have a look.


What is it?

Standing for Voice over Long Term Evolution, VoLTE uses the same LTE network as 4G to transmit voice/calls.

VoLTE is not about 5G.

Telecom Operators in the world are decommissioning their 3G network as they invest on their 4G and 5G infrastructure.
This is problematic for phones who do not support VoLTE, as historically, 4G phones would rely on 3G to transmit calls, which also meant that while on a call, you phone Internet connection would downgrade to 3G, resulting in a much slower connectivity.

For instance, during my last business trip to the US, I couldn't use my Xperia 10 II for calls - however, sending/receiving SMSes worked just fine.
That's because AT&T, the US carrier I was roaming to, has shut down their 3G network, and in order to place calls, your phone must support VoLTE.


  • Since VoLTE does not "downgrade" your phone Internet connection to 3G, you can still browse the Internet while on a call, at the same speed as what you usually have without calling.
  • Calls quality is a lot better, since calls "data" are carried over the Internet.
  • SMS are sent a lot faster

VoLTE in Sailfish OS

On the 10 III

As announced last year during Jolla's 10th year anniversary in Berlin, Jolla introduced support for some of the officially supported Jolla X devices.

The first device supported was the Sony Xperia 10 III, back in May 2022 - it was a beta support, the idea being to get feedback from the community, see which mobile networks worked well etc.

On the 10 II

And then finally, almost out of the blue, Jolla released Sailfish OS on July the 13th - still beta.

Which Mobile Networks?

As mentioned above, VoLTE is still beta, and will not work on all networks.
There's a page on the SFOS forum which lists the providers tested by the community, with a status for each provider:

  • Registered,
  • Voice in (i.e. ability to receive calls),
  • Voice out (ability to emit calls),
  • SMS in,
  • SMS out.

I'm lucky since my provider is Orange France, and it works well.

However, there are networks where some of the above features do not work, or for which you need to call them so that they "whitelist" your 10ii/10iii - a bit annoying and weird.

Enabling VoLTE on Sailfish OS

It's really easy: just head to Settings > System > Mobile Network and enable the "4G calling (beta)" option.

Once you've done that, your phone will register, and after a few seconds, provided your operator is supported, you should have something like the below:

Using VoLTE - what does it change?

I haven't used VoLTE a lot since yesterday, so this is just a quick feedback - it's nice to be able to browse the Internet fast even while on a call, and as for the audio quality, I noticed a significant difference, so that's really nice.

Wrap Up

And that's it! You can now use your Sailfish OS phone with VoLTE - enjoy!

Tags: SailfishOS

I don't have any commenting system, but email me (nicolas at ncartron dot org) your comments!
If you like my work, you can buy me a coffee!