Hi! I’m looking for some purchasing advice on LTE modems like the one in the below picture
I’d like to be able to receive calls, texts and use mobile data from my Linux-based OS. Any suggestions? I heard that modems with voice support are somewhat difficult to find and that Linux support is very hit or miss
Is there a reason you would not use VoIP (plus a normal LTE hotspot)? Nobody has really taken telephony on PC seriously for like a decade+, which is why both hardware and software support is very lacking. There’s just no money to be made in making USB modems anymore.
VoIP is too expensive where I live compared to normal plans, and are also often blocked by services I’d like to sign up for.
I wonder why you would do this. Please don’t if you believe this would be more secure than using a sim in your phone. It really is not.
Then prob. you better go for a standard smartphone? It receives calls and SMS and could be used as wifi hotspot. Use USB thethering if you want.
Or do you have a essential use case for this setup?
Phones are more expensive and have to be replaced more often than something like this, my phone is eol and I’d like to replace it a device that is cheaper, doesn’t/cannot spy on me and that won’t be e-waste in a few years.
It also seems to be more secure than using my phone in its current state. Even if a device like this is “evil”, it doesn’t have microphones, and I can probably operate it safely by passing it to a VM if I feel the need to be extra careful.
Worst case scenario with a device like this (I think) would be to have an adversarial device that has about as much access to my internet data as my ISP and/or carrier, which is not that awful. A phone if compromised can do way more damage.
if you have an EOL phone you have a lot more to worry about than the sim card residing inside of it. There are will be easier ways to get access to your device in that scenario.
Phones need to be replaced now about once in 7 years with current updates on new phones. This seems pretty acceptable to me. Your comparison is rather wrong (sorry) as your usb stick will probably not be even receiving updates and might even be unpatched the moment it ships to you.
Only if you buy a flagship device that’s brand new, and even a used Pixel 8 which is not even current gen costs around 15x~ more than the USB modems with support for voice in my country. Buying a random new phone that has 2~3 years of support is more cost effective (costing between 3~4 USB modems on average) and may offer decent security but also very bad privacy as DivestOS no longer exists. I can’t justify investing that much money on a device that will only see very light use.
Maybe but it’s probably not that bad, as you pointed out the risks of running a eol phone are much higher.
Yeah so i would safe the money spend on such USB device and buy a newer phone lol. That makes more sense.
Yes I’ll go ahead and save up for about a year or go into debt to buy something that costs about 5x the minimum wage and that will only be used for calls, text, and whatsapp. Sounds like a great plan /s.
Unless, do you actually think that it’s better to buy a random new device full of OEM spyware and just use that instead? I’m thinking that there are way less risks associated with potentially outdated firmware from the dongle. Am I wrong? (I’ll quote myself)
(I already consider the ISP/carrier to be potentially adversarial, so doesn’t change much probably)
Not really, but keep us posted if you find anything to buy, because I looked a bit more into this and I really don’t think anyone makes these at all anymore. Voice (VoLTE) capable ones, I mean. If you only need data and SMS that should be no problem.
My knowledge is very limited so can’t get into details, but in order to make and receive calls your device do need to be able to register with your carrier.
Set aside what applications you can use to actually make and receive SMS and phone calls (which I don’t know of any, and I didn’t spend time searching for it), with 2 / 3G phasing out, you really need VOLTE / VONR / VOWIFI for making calls. However, all three protocol require your carrier to support your specific model / variant. You might want to do a bit more research before pulling the trigger.
Speaking of the USB modem itself, most options are made by unknown Chinese brands, which is a huge red flag in terms of product quality, product support cycle, software safety and reliability. Not mentioning the chance your carrier would support VOLTE / VOWIFI / VONR on those modules is very slim.
The security of modern smartphones are also generally better than PCs (with a possible exception of ChromeOS).
Base on the above reasons, I would suggest you invest on a pixel phone, or Fairphone if you want to physically remove camera / microphones, etc., and keep them for 7 (Google) - 10 (Fairphone) years.
I am quite curious in your threat modelling process, as I couldn’t follow your chain of thought.
You’re right. It sucks. Thanks!
Maybe my best bet then is to get some ancient Android device for cheap and perform surgery on it to remove all sensors/mic/speakers, and maybe use KDE connect to receive calls on PC.
If you are only using the phone for making and receiving calls/sms, it might even be reasonable to just install lineageOS to your current device if possible to stop any passive spying and treat it like a dumb phone + hotspot. I don’t think the security of the software would matter much in that case since you wouldn’t be storing any sensitive data on it or introducing risk by installing apps/browsing the web, unless you have a very high threat model.
Yeah, the problem are the mics/camera/speakers/sensors; since it’s not that old it might be trickier to remove everything but I don’t know, I still need to do more research on the matter.
What threat exactly are you worried about? Not installing any 3rd party apps and using LineageOS would stop any passive surveillance. In theory the OS itself could be compromised from the beginning or someone could plant spyware on the device, but the former is relatively unlikely and the latter implies a pretty high threat model. If you are motivated to do it by all means go for it, but for most people there is probably no need.
kernel exploits, most lineage roms run eol kernels with unpatched vulnerabilities
To be frank, if you use it for nothing more than a hotspot and a dumb phone (i.e. phone calls and SMS), you should be totally fine unless your imminent adversary(ies) is a state (which using mobile services would be very unwise).
I found this WWAN card for LTE: Quectel EM12-G. It’s not USB but can be bought with an adapter from AliExpress, it supports VoLTE and is a global model. I could also plug it directly to the WWAN port on my Thinkpad.
From my research it should work with carriers in my location, though it’s a bit expensive (almost the price of an entry-level phone) so I’m not 100% sure that it’s worth it.
From this thread from purism forums, they were able to initiate voice calls with it albeit with audio issues that may or may not also happen on my hardware.
This is what annoys me.
I just need to make a connection to the service (with a modem). I already have a mic and compute power with my desktop/laptop to do the conversion from analog sound to digital signal (as opposed to needing to use a separate computer in the form of a cellphone), I just need to connect to the provider’s network.
I cant believe it is sort of difficult if not impossible to do these days. The modem hardware is so much tied to the main hardware that it takes special hardware like Pixel to separate the baseband to the motherboard.
This way if the modem device is already no longer supported by the manufacturer, you can replace it modularly like an aging GPU or CPU.
I wish Framework would also enter this 5G/LTE modem market.
