Does Librem 5 have VoLTE certification on Ting/T-Mobile?

[Euclid33]

I’m ready to order a Librem 5 today but before I do so I’d like to be confident that phone calls and SMS would work on my network provider. I live in New Jersey, USA. My network provider is Ting, which is an MVNO that uses T-Mobile’s GSM infrastructure.

Ting uses LTE bands 2, 4, and 12 (per https://www.frequencycheck.com/carriers/ting-gsm-united-states). All of these bands are supported by Librem 5’s BNM818-A1 modem.

VoLTE support in hardware and software PLUS VoLTE “certification” from the carrier are required these days, unfortunately.

I have two simple yes or no questions which I cannot find answers for:

1. Does the Librem 5’s hardware and software support VoLTE?

2. Does the BM818-A1 modem that comes with Librem 5 have VoLTE certification with Ting/T-Mobile? (Ting says they don’t have the answer to that question, they implied that I should ask Purism–see their post from July 1, 2020 here: https://help.ting.com/hc/en-us/community/posts/360027576294-Librem-5-does-Ting-support-).

Thanks!

[steve]

I’m using one via tracphone on T-Mobile. T-Mobile’s site says it’s supported entering the IMEI number for the modem, so I believe it is certified with them.

However, I’ve had trouble with VOLTE (when enabled):

1. When VoLTE is enabled you get no ringing feedback when calling someone else (your phone rings for incoming calls of course).
2. Sometimes the calls just don’t seem to go through for specific numbers. I don’t know why.

Still have 2g in my area so I use that for calls.

[amarok]

See @Kyle_Rankin’s comment (he’s the CSO for Purism):

VoLTE support progress

For what it’s worth, I have been testing out VoLTE over T-Mobile networks by enabling the VoLTE mode on the Librem 5 modem (which is disabled by default right now). Once enabled, I can successfully receive calls over 4G. Unfortunately when I attempt to place calls, the carrier disconnects them, sometimes after the other side rings, sometimes before. When in this mode I have to go into modem settings and tell it to be 3G only and then I can place an outgoing call. This leads me to believe that …

@Euclid33

• Does the Librem 5’s hardware and software support VoLTE?
• Does the BM818-A1 modem that comes with Librem 5 have VoLTE certification with Ting/T-Mobile? (Ting says they don’t have the answer to that question, they implied that I should ask Purism–see their post from July 1, 2020 here: https://help.ting.com/hc/en-us/community/posts/360027576294-Librem-5-does-Ting-support-).

1. Hardware: Yes / Software: Yes, but not yet enabled in the UI, as they’re still working out the kinks.

2. Checking a Librem 5’s IMEI (BM818-A1) on the T-Mobile BYOD compatibility page indicates it’s approved. (This modem is commonly used in automobile systems.) T-Mobile doesn’t really have to specifically whitelist a phone (although the other networks do, I believe). As long as it’s compatible, they’ll activate it.

You might also want to check the following:

Will my existing SIM card work? What countries and networks will be supported?...

https://www.frequencycheck.com/carriers/t-mobile-united-states?c_id=3019349

P.S. You could also check this map (zoom way down to your frequented areas, then click on the 4G icon at bottom right), to see the reported tower coverage in those areas, to see how the frequencies used by the L5 and by T-Mobile match up:
https://www.nperf.com/en/map/US/-/85.T-Mobile/signal/?ll=44.59046718130883&lg=-96.72591384065053&zoom=4

[Euclid33]

Thank you, @steve and @amarok! I’m a bit concerned about what Kyle_Rankin said about outgoing calls. If Librem 5 + T-Mobile in USA does not have reliable outgoing calls on VoLTE, then I cannot move forward with ordering the phone. (What the phone can and cannot do on 3G is not relevant given that all the major carriers are phasing it out in favor of VoLTE.)

My must-haves in a phone are few:

1. Phone must use free software and answer to its owner (not FAANG or anyone else)
2. Receive calls and text messages reliably on my network
3. Make calls and send text messages reliably on my network

It seems that Librem 5 checks items 1 and 2. I will wait it out until I can have all 3. I don’t think these 3 items are too much to ask from a $800 phone.

[steve]

Though it feels a little wrong saying this on a Purism forum. The pinephone I have worked fine with VOLTE using mobian. It also worked fine checking all of those boxes.

Niether support mms, so if you need that I believe ubports on the pinephone supports that.

It does have it’s own annoying quirks (like the mute botton does nothing).

[Euclid33]

Hi, steve. Don’t feel dirty–information wants to be free

I appreciate all the valuable information. I have been watching both Librem5 and Pinephone for a few years. I’d rather support Purism if they can manage to satisfy my short list above. I will wait another year or so, then will move ahead with Pinephone if Librem5 is still not checking all three boxes.

Happy hacking!

[irvinewade]

@steve

The pinephone I have worked fine with VOLTE using mobian.

The Pinephone has a soldered on modem (Quectel, IIRC) that is completely different from the currently available modem module for the Librem 5 (Broadmobi).

Why VoLTE on the Librem 5 works with some mobile network operators and not with others, works in some scenarios, not in others, well that’s all the fun of debugging. I’m sure Purism will get there in the end. Patience is a virtue.