AweSIM and VoLTE status

Can anyone give an update on the status of VoLTE calling with an AweSIM SIM in their Librem 5?

… so specifically in the US?

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I can only assume there is no one on here that has an AweSIM that is working with VoLTE in their Librem 5? This is really sad, as the lack of VoLTE is basically the last thing that is preventing the Librem 5 from being a legitimate smartphone (even one I am hoping will be my daily driver for my personal phone). The Librem 5 is a very neat pocket computer in a (thick) smartphone form factor, but without VoLTE to allow for a phone call via a cellular carrier, it’s not really a phone. I say this as someone who has experimented with SIP calling on my Librem 5; SIP calling is nifty, but it’s not ready (or robust enough?) to make it able to be a dependable phone.

As best I can tell, the Pinephone/Pinephone Pro already allows for VoLTE calling (e.g. see this webpage Perhaps I need to try to get my hands on a Pinephone Pro and install Mobian on it.

VoLTE can be enabled on the modem. However, there are issues with it at present. My understanding is that the problem is a firmware issue with the card.
I don’t know if there is firmware available that works and purism just needs a mechanism to flash it or if it doesn’t exist and is being waited upon, or both. At least for the BM818-A1, for the others I have heard people have had better luck with VoLTE.

I don’t think anyone disagrees that this is a big issue. However, based on this report it sounds like the pinephone pro is also rough around the edges at present (general estimates are on the end of the year for it’s hardware being ready that I have read).

It also turns out that T-mobile is turning off it’s 2G at the end of the year. AT&T has supposedly shut down 2g years ago, and 3G at the beginning of the month (thus calls without volte should not be possible with AT&T). Thus it seems the L5 has until the end of the year to get that working.

Thus my plan it to wait until October and see where things stand. If the L5 isn’t ready by October, my intention is to buy a Pinephone Pro and donate some to purism for the software development. I’d rather purism succeeds due to doing a lot of the heavy lifting in terms of software though.

And from what I’ve read, T-mobile is planning to shut down 3G in July, after having previously delayed it. I’m reasonably sure all the networks have been doing this incrementally already anyway.

T-mobile, and MVNOs on T-mobile’s network, are really the only option in the U.S., as the BM818-A1’s IMEI is rejected for activation on the other networks.

Strange that AweSIM is over AT&T’s network, but the BM818-A1 is not being rejected, according to @Kyle_Rankin. (Whether or not non-VoLTE calls can connect is another story.)

As I read Kyle’s response, he didn’t actually say it was working with AT&T:
“AweSIM MVNO is working just fine with L5.”

Purism has been extremely interesting with their use of words, so when I see a response with a generic “AweSIM MVNO is working” (i.e. without explicitly confirming it is working with AT&T’s network), I’m skeptical.

It’s published on the main site. See the “Coverage” section:

Interesting. I thought before it relied either on the T-Mobile or the AT&T networks, but that webpage only lists AT&T (at least currently). Of the two networks, it was my understanding that T-Mobile was the one that cared less about what device you used on their network.

I did more reading on old posts, and T-Mobile definitely had been an option for a network backbone. Apparently Purism gave up on using T-Mobile as a backbone network and is only focusing on using AT&T. That is confusing, however, as it seems that AT&T has shut down its 2G and 3G, leaving only 4G as an option for the Librem 5. Calling on 4G requires VoLTE, so…I can only assume Purism has worked with their AweSIM subscribers to enable VoLTE on the L5 modem and it’s working on the AT&T network? It would be really cool if someone that is not employed by Purism could confirm this.

Not until Feb. 22…unless:


Interesting; thank you for sharing. I guess we will find out for sure on Wednesday if AT&T’s 3G got shut down.

After Kyle Rankin confirmed in the other thread that VoLTE was working for him with his AweSIM service, I decided to see if I could get it working with AT&T directly (being as their plan is $70 cheaper for the plan that fulfilled my needs). After promptly receiving the SIM from AT&T, I put it in my Librem 5 and was surprised to see it seemingly successfully connect to and register with AT&T’s network. I even saw 4G in the wireless signal portion of the screen. To my further surprised, calls worked too…but only on 3G. Apparently AT&T’s claim that they shut down their 3G network on Tuesday was not completely true, as I was able to make and receive calls on the 3G network. That said, 3G is being killed, so I attempted to get VoLTE working by running the commands that are supposed to enable VoLTE for my Librem 5’s BM818 modem. Unfortunately, calls were still not going over VoLTE. I then spent at least an hour on the phone with AT&T, going back and forth with the representatives. At the end of it, I think they may have killed my AT&T 4G data, as my Librem 5 stopped being able to use data when only 4G was enabled. The AT&T representatives claimed that my phone is incompatible with AT&T’s network, which means either: one, the AT&T representatives are incompetent and are only reading off what they see on webpages about compatibility (quite likely), or two, Purism’s AweSIM service actually won’t really work on AT&T’s network, either (which is also possible, although I would like to think that maybe Purism could fight AT&T better than I could to get 4G and VoLTE working).

All that being said…I’m probably going to kill my prepaid plan with AT&T. I now have the choice of trying T-Mobile (or an MVNO running on T-Mobile’s network) or trying the AweSIM service (which is stupid expensive for what I need).

If VoLTE doesn’t work on T-Mobile’s network, an AweSIM subscription may literally be the only way to have VoLTE voice calling on the Librem 5 in the USA (assuming Purism can actually get and/or keep their MVNO service working on AT&T’s network).

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Did you mean “not going over VoLTE?”

I wonder if the 3G calling was a case of implementing roaming over T-mobile… See: (The paragraph that begins “In 2011.”

Of course, maybe AT&T really hasn’t completed shutting down 3G. It sucks to be in the dark about all this stuff.

Unsurprising, given their whitelist/IMEI check.

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Correct, I mistyped and meant it was not going over VoLTE.

If AT&T has a whitelist that they enforce, how does Purism’s MVNO get the same model of modem to work on AT&T’s network? Purism can’t do magic; they are using the AT&T network, so it has to be allowed on AT&T’s network or it won’t work.

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I wonder if Purism, being a MVNO, has bargaining power with AT&T that the Average Joe does not have. For example, Purism tells AT&T they will be a MVNO on their platform (which I assume entails some fiscal benefit for AT&T, probably from Purism), but only if AT&T allows them to have certain modem models (e.g. the BM818) be allowed on the network. Thus, AT&T has a whitelist that they will allow a bunch of approved devices on, but they can manually make exceptions for IMEIs that Purism has on its AweSIM MVNO. The benefit for AT&T is presumably monetary compensation; the benefit for Purism is they can offer a wireless service in the USA that the Librem 5 actually works on.

I think I’m still going to try a cheap T-Mobile prepaid plan before trying AweSIM for $100/month, but I’m less and less hopeful for the Librem 5 will be usable by anyone other than tech nerds with a bunch of extra money laying around.


Just made my first voice call on 4G (LTE AT&T Network) using Purism awesim on an L5 with US modem. I also received a call and while the ringing is laggy, the call quality is excellent and i and the other person heard the ringing. Plus it did not drop to 3G neither has the modem or connection dropped out at all last hour testing it.

It took a while to get the correct awesim activated since my account had tons of dupes for some reason but with help from purism support they worked it out, couldnt be happier.

Honestly i have no idea what would be different technically between 3G voice and 4G voice, i assume both use a digital signal and connection not analogue, and wouldnt that by definition make it VOIP wouldnt that even include 1G, 2G?


Yes but 4G can use superior codecs. So it is possible that you will notice better voice quality on 4G as compared with 3G. Whether it actually is using a better codec, well I don’t know how to check that on the Librem 5 and it might be hidden from the phone and only known inside the modem, and whether you would notice it anyway are open questions.

Maybe but that in and of itself would undermine the idea that you can (very theoretically at this stage) take out the existing M.2 modem card and put a random M.2 modem card in, where you yourself could in theory have written the necessary interface code to run in the Librem 5.

True freedom to replace and/or upgrade as you see fit would mean that the whitelist is thrown away.

I have no idea what reality is.

I have less experience with traditional digital audio, but my understanding that digital audio is not technically Voice over IP, although VoIP is digital communication.

It is my understanding that all cellular modems are black boxes at some level, so even the theoretical freedom described is never truly attainable in today’s cellular environment (even if there was a genius would could code all of that himself).

interesting point i think to clearify these discussions wouldnt it be better to discuss what codecs are used, supported, amd i know 4G has encryption and 3G does not, who owns the keys etc, if voice and data can use the same basic internet protocols or ride on them then the network provider wouldnt be all that much wiser what you are using the phone for (assuming it is encrypted and you have the keys).

A way to circumvent the whole blocking you can just tell the provider its a hotspot device that typically has worked for me in the past (also means no voice using tradition service though).