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 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.