Phone calls stopped working when 3G was shut down in Sweden. Need VoLTE?

Hardware Librem 5
1

During the last few days (early December 2025) phone companies in Sweden have shut down their 2G and 3G networks. For me this seems to have the effect that phone calls no longer work on my Librem 5. (Mobile internet connection still works, using 4G.)

What could I do to get phone calls working again? Should I enable VoLTE and if so, how is that done?

2

Yes. (You probably ought to have done this already since VoLTE worked for years before it finally actually became mandatory in your country.)

Install the package bm818-tools and there is a check box to enable VoLTE. You should reboot after enabling VoLTE and before attempting to test it.

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3

Thanks! Now I did that, but it’s still not working. I did reboot, and I checked that when starting bm818-tool again after reboot the “VoLTE enable” checkbox is ticked there now, so it looks like VoLTE is now enabled.

When trying to make a phone call the call ends directly, kind of as if the other side had rejected the call.

The journalctl log shows ModemManager messages saying

call state changed: unknown -> dialing (outgoing-started)

call is started

call state changed: dialing -> ringing-out (unknown)

call state changed: ringing-out -> terminated (unknown)

(The ringing-out -> terminated happens after only about one second so the “ringing-out” part is really short.)

The bm818-tool program has two checkboxes, first “VoLTE enable” (which I checked) and then also another checkbox “CBS enable”, should I check that one also?

4

You should check your modem firmware also

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5

Definitely not. That’s Cell Broadcast Services.

Quick sanity check … while logged in as purism, use the groups command to verify that purism is in the dialout group.

6

No dialout group seen there.

The groups command gives the following output:

purism sudo audio video systemd-journal render netdev feedbackd

Should I then add the purism user to the dialout group?

7

Yes. (I had to. But then I thought my environment was sufficiently unique for this to be a problem only for me … Apparently not.)

So I think:

Disable VoLTE (will actually fail but do it anyway)

sudo adduser purism dialout

Then reboot

Then re-enable VoLTE

Then reboot

Then test again. (I’m reading my notes from when I did this. Yeah, a lot of rebooting, but got there in the end.)

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8

There is a option on modem that list all the carries that support volte by the modem. If you carrier it is not there than volte do not get registered. I not sure atm howto see the list.
But if volte do not work it is because it is not on the list.

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9

Thanks, I tried that (adding to dialout group as you described), but still have the same behavior, directly getting terminated when trying to make an outgoing call.

I will try to check modem firmware version as @ASwyD2 suggested.

10

Yes updating the firmware there is chance that you carrier get volte support, but also updating the firmware there is a chance to have a new or updated backdoor.

Other option is to try crossing the firmware to get volte accidentally. Other option is to get a module to compat volte with your carrier, or even better go to 5G module that worked on L5.

Edit: other issue is that your module support volte on your carrier but on different network that ur module it is not capable.

Try first moving to other carrier, before change the module.

11

If the BM818 tool is working, it will be showing you the version.

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It does show a version, now I just need to find what to compare that to.

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Post it here if that’s OK with you or else search the forum for where this exact question of what is the latest modem firmware version has been discussed a few times.

Edit: e.g. Modem specs - BM818 tool - #15 by amarok

14

Now I have updated firmware to the version labeled V1.0.0.2_20220930 which is the same as seen in the screenshot at Reflashing modem firmware - Purism user documentation and I have disabled and re-enabled VoLTE again after that, rebooted before and after, but I can still not make a phone call. Here is what the log says when trying to place a call:

Dec 12 13:00:44 pureos ModemManager[509]: <info>  [modem0/call2] user request to start call
Dec 12 13:00:44 pureos ModemManager[509]: <info>  [modem0/call2] call state changed: unknown -> dialing (outgoing-started)
Dec 12 13:00:44 pureos ModemManager[509]: <info>  [modem0/call2] call is started
Dec 12 13:00:45 pureos ModemManager[509]: <info>  [modem0/call2] call state changed: dialing -> terminated (unknown)

Ideas for how to find out what is going wrong?

The dialing -> terminated (unknown) message is not very helpful. What I would like to know is why it was terminated.

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15

You’re likely experiencing what is going on in Canada. I cannot use VoLTE on my L5 on the Rogers network (likely all the competitors here are the same) because they do not recognize it as a vetted device and therefore exclude it from any VOICE services. Data isn’t a problem, but I doubt you will get VoLTE to work. I think carriers more and more will take a stance of blocking everything and then only allowing vetted devices moving forward. I know this because I work for a small telco in Canada that is partnered with Rogers, and I’ve been told as much from our project managers here.

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16

Do you have a portal that you can access your carrier account? You could try turning VoLTE off and on in there.

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17

@Skalman , look for a device compatibility check on your mobile service provider’s website - as if you were activating new service for a device you already own (aka BYOD). Enter the IMEI of your BM818 modem (i.e. the L5), and see if the modem is approved for activation.

Or call your provider and ask them to check the IMEI. If they tell you it’s not approved, try to convince them. It’s the same modem used in countless automobiles.

If your service provider won’t help, then check with other providers.

If the IMEI is approved, then it’s time for more troubleshooting.

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18

There’s always the option of getting the alternative modem. I didn’t get BM818 reliably working beyond 3G either.

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19

Same problem here in France with Freemobile

I still receive the SMS in 4G but i cannot call with my provider.

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20

In addition to all the other lines of investigation, it is also possible that even the latest firmware version does not have a correct config for VoLTE with your mobile network provider. So it may help to try to find other Librem 5 users in Sweden and/or, as suggested above, to try another mobile network provider.

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