2G, 3G, or 4G on Librem 5

I just reviewed the video demonstration of a phone call being received on a Librem 5. It looks good. Kudos to Purism and to all of the developers who made that demonstration possible. But I do have one concern.

I have never seen the 2G icon show up on any phone that I have ever used. I have seen the 3G icon show up. Typically the 4G icon is there. I can imagine that Purism might really want that 4G icon to be there for their demonstration if it were possible. A non-phone-call part of the demo does briefly show a 4G icon on the phone, before returning to the phone with the phone call on it, at which point the 2G icon returns. Kudos to Purism for being honest. But if their showpiece demo features a 2G icon, I am inclined to see that as a likely disclosure that there are problems with 3G and 4G on the Librem 5. I would like to be wrong in making this assumption. Does anyone here know why that video features a 2G phone call?

Good question, I know the pinephone can call over 4g

Without VOLTE, you can’t make a call with 4G.
Try with your actual phone, even if you use a 4G connection, the phone will switch to 3 or 2G as soon as you start a call.

As the 2 modems proposed for the L5 have less supported band than usually used SoC in smartphone, in some case 3G band will be not supported.

So apparently, the Librem 5 does not support 4G and in some areas will not work with 3G. Is Purism planning to openly disclose this any time soon? I still want to keep my pre-order either way. But it would be nice if this is true, if Purism were to disclose it themselves openly. Some people will not do the research, may not see the video, or may not notice the significance if they did see that 2G icon.

You said yourself you saw the 4G icon. I do believe there are those who have tried to get VOLTE working on their L5s, but as I recall the results were inconclusive.

This is confusing.

Are you talking only about voice calls? Are you talking only about data calls? Are you talking about both? How are you categorising VoLTE?

As @Torrone says or implies above, there is no such thing as a 4G voice call, and VoLTE is the “workaround” for that i.e. a way of using the greater aggregate bandwidth available from 4G for making calls.

Prising the necessary information and support for VoLTE out of the relevant players is probably a future battle.

As presumably none of us has an actual phone to play with, we can only really speculate. If you want an official statement from Purism as to what the current state of VoLTE is and what the future plans are for VoLTE, you would need to ask Purism.

Just for fun:

  • Lack of VoLTE (if that is the case) could be a blessing in disguise, if it pushes more people into more secure calling options.
  • If you have a VoIP provider, you can presumably make insecure phone network calls via that mechanism.

Someone in Pine64 forum seems to got Verizon VoLTE to work on the Pinephone on Debian Phosh and Modem Manager:


any good GUI would let you manually choose between 2G,3G or 4G as 5G is not an option for now (phew!)

it’s probably a good idea to have your phone on manual network selection and network mode than auto for the battery sake … otherwise the phone will keep searching and choosing for you the newer technology …

my bb-q10 stays firmly on 2G most of the time when i have my network-radio-ON and if i set it to auto it immediately jumps to 3G or 4G or the in-between naming-conventions as they are called

it’s been discussed already here in the forums …

I’m not familiar with the underpinnings of calls, but from my testing 4G data works fine. Once a call is placed or received, the connection drops down to 2G or 3G.


It looks like hackersgame has some good information for us. If the data is 4G, that should suffice. I used a verizon reseller for a few years and never had better than a 3G connection there. I noticed no degradation anywhere I went within the verizon network that way. In my mind, 5G is not significant. At 5G frequencies, the moisture in the air causes significant range limitations. So if you are very close to a tower, you might get insanely fast internet speeds. Otherwise, you get 4G which is good enough for me.

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Happy to hear that data does support 4G.
What would be the advantage of voice calls over 3G or 4G?

I am guessing that as the major carriers move toward 4G and 5G, that 2G and 3G towers might become fewer and further between. If this is the case, you may not be able to make calls in those areas if you only have 2G and 3G. For 2G and 3G, the data connection is slower than 4G.


2G is less securely encrypted than 3G or 4G (and creates other sec problems) but takes less power and IoT doesn’t need all the bandwith. 2G and 3g are being phased out globally (in some places it has been done, other operators do it in about 1 to 5 years). 4G will be around for a long time still. 5G has a bit less range/penetration than signals used in previous standards and thus they are going to need more towers, so yes, fewer indeed, in comparison as well.

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unless data connection moves to the star-link satellite sub-orbit mesh-network … i’d rather not encourage having microwave canons pointed at us …

The advantage of voice over 4G is

  • you can carry more calls (advantage to the carrier, not you, but that could have flow-on benefits to you) and/or use higher quality audio
  • 3G will in the future be phased out (switched off) and the frequencies potentially used for other things (but that would be some years away) so hopefully we’ve got VoLTE working by then

Do we know that the Librem 5 will not support VoLTE, or is that an assumption?

If the modem/baseband module supports VoLTE, then it might come “for free”. (As mentioned by @tg_gpm in another thread.)

The PLS8 module supports VoLTE, but I can’t find a good datasheet that says whether the BM818 module supports it. I’m hopeful that it does.

It might not have occurred to Purism that people would be looking for a 4G icon in their demonstrations. If they knew people were looking for a 4G icon and wanted to demonstrate it, they would still have to find a physical location where the cellular network tends to put calls through on 4G.

Even if a phone supports calling over 4G, the network doesn’t necessarily prioritise its use. Where 2G and 3G remain available, networks tend to push voice calls onto them, because it’s an efficient way to use the spectrum until they are able to get rid of 2G and 3G and reallocate the spectrum to 4G and 5G.

I don’t think you can safely assume that the older technologies will use less power. Depending on the local conditions and how much you’re using the data connection, the opposite may be true. Though that doesn’t overturn your basic point: set it to whichever one is the least power-consuming.

It’s a mistake to think that 5G implies high frequencies. In the short to medium term, yes, 5G will be mostly deployed at high frequencies, because those are the bands that aren’t already being used for the older standards. They are the low-hanging fruit.

But in the long term, as more people get 5G-capable phones, network operators will be able to reallocate an increasing proportion of their lower frequency spectrum for use with 5G instead of for 2G, 3G and 4G. When that happens, people will start to experience longer-range 5G signals.

I hope so, too, but I’m still not 100% confident that it will.
I think it’s high time that some of the early adopters share their experience, there should be at least someone with the early adopter hardware out there who could.


No, we don’t.

Only if the provider in that location also supports it and they are compatible.

In the case of the modem, it is possible that a future firmware update will add the support (if it’s not already there). Or maybe that will never happen and one would be looking to replace the modem.

All just speculation.


It is my understanding (and I could be wrong about this) that 5G is deployed only in the higher frequency ranges because it offers and thus requires much more bandwidth per user. The available amount of spectrum increases exponentially as you go up in frequencies.

My understanding is that initially 5G will be deployed in frequencies that are similar to what 4G is already using today. In the future 5G will be deployed in much higher frequencies. In the future of the future 5G may be deployed in insanely much higher frequencies.

As you say, there isn’t major benefit in deploying 5G in frequencies that are similar to those already being used today because there is only so much bandwidth that you can eke out of a given frequency (the bandwidth being proportional to the frequency, all other things being equal). My understanding is that the choice for 5G today is motivated by constraints of existing hardware.

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