That’s a really excellent thought. Those slipped my mind because I had been searching for add-in modules designed for laptops etc.
On one hand, something like a Qualcomm 315 5g modem-on-a-chip looks great. On the other hand… There are so many reasons these are hard to mess around with. Not just in terms of datasheet access and NDAs, but regulatory. Creating legal RF devices is expensive, which is why you see entire modules to provide stuff like WiFi and Bluetooth.
Legalese side note, in the US, the FCC has separate classification tiers for intended radio transmitters like WiFi and Bluetooth radios than it does for incidental transmitters like digital logic. A purely digital device (like a Framework laptop mainboard) can be exempt from certification, and then you just add a WiFi card that e.g. Intel has already gone through the trouble of certifying. I think as long as the resulting system doesn’t change the behavior of the WiFi card as certified and cause harmful interference, the mainboard doesn’t need certification even if it’s sold with the module installed.
See also: Raspberry Pi moving from WiFi chips and full-board certification in the Pi 3 and Zero W to the module-in-a-can WiFi used on every Pi since then.
This isn’t even touching the electrical engineering side. Or the software side, writing drivers for embedded cellular radios that a carrier will allow onto its network… Yikes.
@Josh_Cook would love to hear/see some details on how you fit it and got it working!
$100+ is nothing compared to the premium you typically pay for a laptop with integrated 4G/5G if you can even find one!
The way I did it with my 5th gen Lenovo X1 was to find the manual for installing the optional 4G kit, took the part numbers from there, found the parts on Ali Baba, ordered them and installed it myself.
But of course, the Lenovo X1 was already designed to fit a 4G modem, had an external port for inserting the SIM card, and channels for the wires and dedicated areas for the antennas. Which is why I’m curious about how you handled all these details.
Here’s how the packaging is set up in my Lenovo X1 Carbon - clearly designed for 4G from the start, not an afterthought (antennas at the corners, come with shielding, dedicated SIM card tray in the back):
Just double-checking, I mean an expansion card not using the WiFi slot, I can’t exactly go into detail due to NDA, I’m just waiting on when the actual module I’m planning on using will become available.
A single SMA mounted antenna takes up a lot less room than an external dongle. An antenna shouldn’t extend any further out than the power cable you probably have plugged in does, while a dongle would be several inches long.
I just started designing a LoRa expansion card and my plan is to have an SMA mount. It should also be possible to have a chip antenna for backup. I will have to look deeply into the FCC requirements - hopefully Semtech’s certification extends to boards built with LoRa ICs, but I don’t know.
That’s rad, Josh! Let us know whenever your mysterious partners go public with this project!
To be honest, I don’t think a redesigned mainboard made to be able to accept an M.2 LTE card would be breaking compatibility that much. You might not be able to use Wi-Fi anymore, but from what I have read from this thread, having an LTE card would be better anyway. It may be a bit of a ways off, but it may be the best option. Correct me if I am wrong though; this is my first reply to this thread, and I am also not as knowledgeable with this in particular as the rest of you seem to be.
Can someone explain to me how servicing an LTE modem would work? How do I register it and pay fees to the cell tower companies to turn it on? I’m pretty confused about this.
You get a SIM from the provider you want. Then activate the SIM through whichever option the provider offers, often it’s a page on their website. Usually you can find the option(s) by googling “[service provider] activate” or “[service provider] activate sim”. It varies from provider to provider, if in doubt, contact their customer service and ask about activating a laptop LTE modem.
Often you have to enter a IMEI number when activating a SIM. This is the device’s identification number and will be found on your modem and / or on the box or paperwork.
Once in a while, a provider might not accept IMEI numbers that aren’t on some “whitelist” they have. You can often work around that by using an IMEI from a different device. This works because the SIM is the primary way a device shows it’s authorized, service is attached to the SIM. For example, if you put the SIM in a different device, the service comes along with it (assuming the device has the radio bands and technology to support that service provider).
I never had to provide an IMEI to activate the SIM. PIN, yes, but not IMEI.
Generally, you will be asked for PIN (in countries like Germany or Poland) or it will just work (UK). Sometimes you might need to provide an APN; the provider’s page should help you there. Sometimes, before you can do anything, you would need to register your SIM with some form of official ID (Germany, Switzerland, Norway, Poland, …)
Yeah, this is built into Linux when you use something like nm-connection-editor, it’ll choose the APN for you automatically. Windows is a bit more jank in this regard, had some issues when testing my LTE module before since Windows wasn’t configuring the APNs for my vendor correctly.
Can you share some info on this? I’d love to follow the news on it.
It’s possible their perspective is from the states. Here in the states the primary carriers traditionally blocklisted any device they did not endorse.
I’ve read the mobile carrier situation is a lot more consumer friendly in the UK so while it may be unlikely you encounter that situation, it is always possible.
I believe it is also possible the carrier could detect the IMEI of the device, for example if you activated through a mobile phone instead of a web page which I know some carriers offer as a means to activate a sim.
So, good news and bad news; I’ve found an USB application, the bad news is, it’s pretty expensive (~350-450) and I’m not exactly sure about it’s dimensions.
That does indeed look like a pretty good option. If one were to break out the innards and 3D print an enclosure to turn it into a Framework expansion card, that would be an awesome little 5G package.
