In my experience, UK networks are entirely unfussy about what sort of device you have, so long as it conforms to the relevant standards. VoLTE and MMS support are likely to be more variable than support for basic calls, SMS and data.
I will have to have another try at making an account on source.puri.sm in order to contribute to the Wiki.
In the meantime, here are the details of my personal experience:
Location
Provider
Bands provided
Modem
Calls
VoLTE
SMS
Data
Notes
UK
Three
GSM: No UMTS/HSPA+: 2100 (B1) LTE: 800 (B20), 1800 (B3), 1400 (Not supported by modem), 3400 (Not supported by modem)[source]
In practice, according to Cellmapper.net, almost all Three cell sites seem to operate on bands 3, 1 and 20, with 3 the most common, followed by 1, and 20 the least common. Where other bands are used, they seem to be in addition to these main bands, so modem compatibility is a non-issue.
BM818‑E1
Yes
Yes*
Yes
Yes
Data, SMS and 3G calls all work flawlessly.
MMS not tested with latest software but probably the same as ID mobile as they appear to use the same underlying MMSC.
*I had VoLTE enabled all the time and found it worked fine for me, but see note about VoLTE on ID Mobile, which might also apply to Three as it’s the same physical network (not tested).
UK
iD Mobile
Same as Three UK
BM818‑E1
Yes
Yes*
Yes
Yes
Data, SMS and 3G calls all work flawlessly.
MMS is a work in progress. After inputting the carrier’s settings, I can currently receive MMS messages fairly reliably but I can not reliably send MMS messages. I need to investigate logs and report a bug when I find the time to do so.
For some reason, the operator’s name appears as i" instead of iD on the Librem 5, but this does not seem to affect operation. Again, I need to report that as a bug at some point.
*I have VoLTE enabled all the time, and it works fine for me almost all the time. This has remained consistently the case, except that, one year ago, I discovered at least one specific geographic location where the phone would not ring for incoming calls when using VoLTE, making it seem like I was ignoring calls and breaking outgoing calls. I had to switch to 3G in that location. [forum post] It’s possible the experience may have improved since then, as I haven’t tried making or taking a call in that location recently. VoLTE still works fine in the places where I normally use it.
Looking on Cellmapper.net, I see:
Vodafone mostly uses bands 1,3,7,8 and 20, which are all supported by the BM818-E1.
O2 mostly uses bands 1,3,8, 20 and 40, which are all supported by the BM818-E1.
EE mostly uses bands 1,3,7,20, which are all supported by the BM818-E1.
Since Three, Vodafone, Orange and EE are the underlying network infrastructure for all other UK mobile networks, I conclude that, while I have not tested all the networks, the Librem 5 with a BM818-E1 modem should be able to connect to almost any 2G, 3G or 4G network in the UK, in almost any location that has a signal for that network.
This is not specific for L5. I live in one of these spots (in Kuala Lumpur) with low signals and experience the same on a Samsung mobile (my L5 not yet arrived). The caller gets the message that my phone is “busy”.
I was describing a different situation, in which the caller heard a “ringing” tone to indicate that my phone was ringing, even though it was not. This was something I confirmed with the caller afterwards, when we met up. However, re-reading my old forum post on the topic, I see that I was unsure at the time about whether or not my phone had actually rung for the incoming calls I’d missed. So perhaps it did ring and I simply failed to hear it, meaining this would have been less of an issue than I remember it being.
Yes, the ringtone is generated by the network (not your phone). In my case the network provides a “busy” signal (as if I’m already talking to someone else). My caller told me:“you where busy the whole morning”…
Note: In my place the phone fails back to 2G. Also, there was no registration in my phones “missed calls” list.
I was looking at the table again and I realised that the information I provided is now out-of-date. As far as the compatibility between the Librem 5 and the iD Mobile network goes, MMS works both ways now and I haven’t noticed any VoLTE problems recently.
The network itself has been a bit unreliable recently, but that doesn’t seem to be anything to do with phone compatibility.
For the record, I think this was still a misunderstanding of what I was trying to say. There are no circumstances where it is correct for the caller to hear a ringing tone without my phone indicating to me that I have an incoming call.
If the network cannot make my phone ring, then it should put the caller through to my voicemail or at the very least play a busy tone or a recorded message. That’s how phones work here. Ringing tone means the phone you are calling is ringing. Everyone knows and expects this.
Hearing a ringing tone, callers would reasonably assume I was either ignoring their call, or I didn’t hear it but I would see it in my missed calls when I next looked at the phone. They would not assume the line was busy or my phone was unreachable, because a ringing tone is not used in those situations.
The fact that the caller heard a ringing tone, while I saw and heard nothing at my end, was unquestionably a failure of either the phone or the network. But this is all academic as it happened a long time ago and I haven’t knowingly experienced it since.
Not disagreeing with what you are saying but the current behaviour of your phone network could be construed as an unnecessary privacy leakage. Should someone be able to know that you are on the phone if you have not authorised that? (In other words, for a flexible phone like the Librem 5, you could legitimately choose different behaviour.)