My Librem 5 with the most basic AweSIM recentl arrived and for various reasons am taking getting up to speed with it slowly. One of my top top priorities is making sure cell service is working as currently expected and what any limitations are since it is incurring a monthly charge. I also want a feel for the current expected situation before contacting Purism support.
I am having 2 main problems.
When I call a number answered by a navigation menu, the dial pad does not seem to generate any signal. That is, the menu doest not respond at all, either waiting “forever” or repeating directions/choice possibilities. I’ve found a number of old threads, but can’t tell whether it has ever worked or is even on a roadmap. Telling me to update without also supplying information about a version that does work is not responsive to this question.
This would be number 1 but it is a bit more complicated and has more than one sub-part. Sometimes a call doesn’t go through and when this happens, sometimes I get a text about “unapproved device”. Purism documents that this is “normal” when “3G activity has been detected”. The phone came presetup for AweSIM (a much appreciated service), including set to 4G only. One thing I tried while playing around was disable mobile data. Does that disable VoLTE? I do know that when I reenable mobile data calls still don’t always complete, even after one or more power cycles and I also sometimes get an “unapproved device” text. I have also had cases where one number reliably answered but another land line with a hardware answering machine which never answered until a friend called it for me and it did. I tried that number later with my Librem 5 and it finally did answer.
I know there are people daily driving a Librem 5 and I want to know how to avoid the problems I am having and whether dislpad DTMF should work after a call has been answered.
Can’t believe no one tried to help this guy when he posted…
DTMF never works for me in my work office building. Hell, voice only works sometimes, even though I have 3 or 4 bars and it shows 4G. I assume this is due to many huge metal hangars and many aircraft radiating all over the spectrum. I can walk across the parking lot to another building (away from the hangars and ramp) or drive a couple of hundred meters down the street and voice and DTMF are fine. I must say though that even when DTMF works, there is no audio feedback (I can’t hear the tones). It’s not about the service I’m connecting to, it is a good strong signal with no multipathing or interference.
I’m pretty sure AT&T (AweSIM carrier) has shut down 3G in my area. I am reluctant to experiment because of the nature of the text message as described in “2.” in message #1. I have an ereader that could download books over 3G that stopped connecting over a year ago. In any case, my L5 has never dropped down from 4G to 3G, although maybe that is attempted when mobile data is disabled, with VoLTE left enabled, as described in message #1. That is, I can not make calls on my L5 when mobile data is disabled, which is extremely annoying.
Thanks. I don’t think interference was the problem. However, I tried again, and now it works. I have no idea what changed. Last August I tried in a number of locations and it never worked and I pretty much gave up until now.
From what I’ve read, DTMF audio feedback has never worked on the Librem 5. Fortunately the dialpad entry box shows which keys have been pressed.
It is depressing to read in the other recent threads that DTMF in the digital world is so complicated and problematic. It has been rock solid on POTS for many decades. One place I call has switched to an AI based voice recognition system that is terrible even when line quality is good. It has been my experience with systems that use both voice recognition and DTMF that DTMF works when the line quality is so bad that even a good voice recognition fails.
The thing is … DTMF was designed expressly for carrying digital-like information over an analog audio channel. Once the analog audio channel is replaced by a digital channel, the whole thing makes no sense. You would never design such a thing if starting from scratch today but we are of course stuck with it for a long time to come.
I would guess that that is a purely local software issue but I don’t know whether the phone software or the modem software is supposed to produce the feedback. However an argument can be made that audio feedback is broken security and having no audio feedback is more secure.
(If you dial your PIN on a phone that gives true DTMF audio feedback and someone nearby records the sounds then they can decode your PIN offline using software. A talented musician can probably decode your PIN in real-time without any technological assistance.)
To be honest, about the only thing that I use IVR for on the Librem 5 is accessing the MNO-provided voicemail. And it “just works”. So I never really gave DTMF on the Librem 5 much thought until now.
I understand that your topic has been hijacked (which I have now tidied up). My questions were all directed at