Librem 5 - Daily Driver Switch (and missing calls/sms)

After a long wait, I finally received my Librem 5 a couple of months ago.

I played with it for a few days, but ultimately the battery life led me to use it as a paper weight on my desk.

Thankfully though, not even a few months later, suspend was made (more) stable which drastically improved the battery life.

I am a moderate user, with wifi HKS off all day, and I require just 1.5 charges per day. This is manageable for me, so not a huge deal.

What is a huge deal, is that I will occasionally throughout the day miss calls and SMS.

My wife will email me and say that she has been sending me SMS, which never go through, or calling me which goes straight to voicemail.

The bad part is that the phone does not give me any indication that there are issues. I have 70%+ signal strength, and see the LTE icon.

When this happens, and she tells me that I am missing calls, and even though there is no visual indication that something is wrong…I am also unable to make outbound calls/sms.

8/10 times, toggling the HKS will get things working again…but in order to use this as a daily driver, I need to get calls reliably (for emergencies).

I am not a linux guru, but what I found is that dmesg doesn’t show any difference. When things are working, I dont see any errors…and when they arent, I dont see any errors. (One) of the last logs I see is that I am ‘authorized to connect’ in both cases.

I really dont want to go back to my Graphene OS device. I am loving Phosh & my Librem 5…but need to figure out what is going on here.

Even if the modem is not currently stable, at least a UI feedback would be nice to let me know that I could be missing communications.

Any ideas from the community?

I am also willing to provide more logs, and troubleshoot given I am provided with some steps. I may not be a linux guru, but pretty comfortable around the command line (given I know what to execute).

FYI, I am in the US using an MVNO (AT&T).


The problem is likely AT&T. The L5’s US modem isn’t one of AT&T’s (few) whitelisted devices. Even though you’re using an MVNO, the MVNO has to comply with AT&T’s device requirements. I’m guessing you’re using a SIM that was already activated in a separate, authorized device, right? Otherwise, AT&T (or MVNO) would not have activated it in the L5.

One problem, too, is that even if AT&T doesn’t eventually block your SIM, you probably won’t be able to get VoLTE working on AT&T’s network, since the modem isn’t approved. Additionally, AT&T has no 2G or 3G network for calls to fall back to in the absence of VoLTE (voice over 4G LTE), so this will render calls inoperative.

T-mobile and related MVNOs, however, do approve the modem’s IMEI for activation and use on their network, and it does get VoLTE, and even has 2G fallback. VoLTE can be enabled on the L5 via the BM818 Tool app.

For the phone to be reliably woken up from suspend by the modem, the modem firmware needs to be up-to-date. You can check it in sudo picocom /dev/ttyUSB3 by typing AT+BMSWVER (you won’t see it being typed). The first part of the reply needs to be M100E_YCSN0_1.0.0_220926 or later. If it’s older, you can contact support to get it updated.

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So I take it that your phone has completely up to date operating system software?

When you’ve fallen off the cellular network, do you still have mobile data? If not then maybe you can put something on the phone to test access to the internet periodically. That way, if you fall off the network then the phone can alert you and you can toggle the HKS (or maybe there is a script available to do something in software to get you back on the mobile network). I understand that that would just be a workaround.

I can only speak from my own experience, but my Librem 5 does not have any network related problems on AT&T and as far as I can tell uses VoLTE without issue.

My experience is very opposite what you describe.

Thanks. I’ve done this but AT+BMSWVER returns me an ERROR. I live in Europe. Any idea to check that?

Keep in mind that you have to type it verbatim, you can’t use backspace etc. If you get “ERROR”, try again and be careful to type it exactly as it is (can be lowercase though).

You can also start by typing ATE, will will enable character echo which should make it easier. Type ATE0 after you’re done to disable it.

thanks. I toggled the hks once or twice then i worked from the first time. it is up to date for me. I returns me M100E_1.0.0_190426,BMC_M100E_1BAD_3117_V1.0.0.0_20190426,M100E_1.0.0_190910
I’ve contacted the support.

That’s interesting… I wonder if AT&T is letting it slide because it’s an automotive-identified modem, or just hasn’t noticed yet. Good news, if it continues.


Ultra Mobile is a AT&T MVNO that allows you to register the BM818 modem on their network. However it does not get a signal as well as AT&T
Edit: I do not use Ultra anymore because of service issues.

Ultra is an MVNO on T-mobile’s network, unless something has changed:

Huh, when I was using it I thought it was under AT&T🤔
Makes sense why the service was not good.:laughing:

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If you check their coverage map, it’s all magenta, indicating T-mobile. AT&T’s map would be blue, I believe.

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Mine is M100E_YCSN0_1.0.0_210122.
I live in Europe too.

I’d like to test a newer firmware since I experience some issues with missing SMS/calls as well as mobile data (to get 4G mobile data working, I have to go to 3G then switch back to 4G).

I assume many of us have an old firmware. Is there a way to update it without anoying the support ?

If it was annoying to support they wouldn’t make contacting support the only way. Don’t think of it as annoying support when it’s the only option provided.


Updating the firmware with help of support is really quick and easy. No need to hesitate.

They made guides for everything important like flashing Librem 5. So why Purism only wants to provide the way over Support? I don’t know, but seams there is an important reason.

Yes; if I recall correctly it is because it’s to error-prone. Steps not done right can lead to a state where the device is not flashable anymore by the user and has to be sent to support. They surely want to avoid that. Especially so that only people flash the firmware who experience errors.

Imagine a public available doc which will be outdated some time. Or people flash wrong versions, …


and, if I recall correctly, the instructions may not necessarily cover all scenarios and error cases. So better to limit it for now to those who have a genuine need to update firmware.

Or you could just ask your country’s spy agency to update it for you over-the-air (OTA). :rofl:

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