The Crowdsupply page tells us the Pocket Reform has support for an M.2 key B WWAN slot for a 4G/5G/LTE modem. And it says: Alternative to smartphone (data or VoIP only).
Update #8 says: Originally, we intended Pocket Reform to be usable as a music player and to make (voice) calls.
What prevents one from making or receiving 4G voice calls akin to a smart/dumbphone? Is it the apparent absence of a microphone? And if, would a bluetooth headset be sufficient to support making 4G calls?
The Pocket Reform seems much similar to a Librem 5 hardware-wise. The Librem 5 is capable of making/receiving voice calls.
What makes you think that the Pocket Reform cannot be used to make voice calls?
o The specs says data or VoIP only
o There seems no mention of a microphone in the specs or elsewhere
o Update #8 says intended to make voice calls, implying that is not the case anymore.
I honestly thought I mentioned all of this in my OP.
I think update #8 is just not well phrased. It uses past tense because that was the intention back when the pocket was initially brainstormed. But the ability to do voice call was never axed. There is no reason why the pocket should not be able to do voice calls with a bluetooth headset for example.
Actually, wait… When you say “voice call” you mean via voice over ip, right? You do not mean calls to the cellphone network to a regular phone number, right?
Ah no, I mean traditional 4G calls using phone numbers.
Ah okay good i asked.
No, those will not be possible. The pocket reform is not a smartphone but just a very small laptop with a modem. So it will work the same way as when you attach a modem to your laptop. When you do that you can make voip calls (because you have internet via LTE) but you cannot make phone calls to a phone number.
Hence my question: what does actually prevent one from making/receiving 4G calls?
The Librem 5 is a very small laptop without a keyboard and with a modem. It is really very similar to a Pocket Reform from a hardware perspective.
The difference is the modem and how it is connected to the rest of the hardware. For example, if you ever had a USB LTE modem that you connected to your laptop and you started sending AT-commands to it to do voice calls you will either see that the modem itself forbids to do those (as it was built to provide internet to a PC and not to make phone calls) and if it works, you will not be able to send or receive audio because those are not connected to the relevant parts of the modem. In the Librem 5, the audio obviously is connected in the right way and the modem is chosen to support this. Maybe there is a way to hack this in on the Pocket but as far as I know there are no plans to do this right now.
Maybe @mntmn can confirm this.
Thanks a lot for your reply. That makes sense. Being able to make/receive phone calls would make the Pocket Reform quite irresitible to me …
In the latest revision of the Pocket Reform motherboard I am now connecting the modem slot’s PCM lines to another SAI (digital audio) port of the i.MX8MPlus. Let’s see if it’ll do something useful.