Questions about completely removing the cellular modem

[user0]

I have absolutely no trust in cellular service in the USA.

Three corporations (Verizon, AT&T, and T-Mobile) own and control all cellular service here. They have been caught illegally selling location data and ordered to stop, and then they were caught continuing to do it anyway and have faced no consequences. The Snowden leaks revealed that deals were made between the US government and these corporations. They are required to do certain surveillance work for the government agencies that are legally barred from doing so themselves, and in return they are granted immunity from legal repercussions for surveilling the public.

And so, I have no use for the cellular modem in my Librem 5.

I had originally thought that I should keep the cellular modem in case I ever needed to call emergency services, but recent events have shown that calling emergency services in the USA can result in unnecessary interactions with violent police officers armed with deadly weapons. I can no longer think of a single instance in which it would be safer to call emergency services than not. Handling emergencies myself and/or with the help of family, friends, and neighbors is the safer option.

With that said, I am curious about the implications of completely removing the cellular modem from my Librem 5, rather than simply having the killswitch set to always block it from powering on.

So I have some questions:

1. Has anyone working at Purism tested a Librem 5 without any cellular modem installed?

2. Is the Librem 5 designed to be fully functional without the cellular modem?

3. Will the Librem 5 eventually be able to wake from sleep for notifications from encrypted texting and calling apps and the alarm clock without the cellular modem being powered on or installed?

4. Could removing the cellular modem cause the Librem 5 to be warmer or cooler when in use?

5. What should be used to make the antennas stay in place and not rattle around (tape, glue, or something else)?

6. With the cellular modem removed, does the cellular killswitch do anything (good, bad, or neutral)?

7. If the cellular modem is removed, can the cellular killswitch be used to disable Lockdown mode while keeping the other two killswitches set to block WiFi/Bluetooth and Cameras/Microphones? (this could enable offline map access with GPS and other sensors)

8. Is Purism still considering a non-removable cellular modem for the next version of the Librem 5? (if so, please reconsider)

9. Has Purism considered selling a variation of the Librem 5 that does not have a cellular modem at all (still capable of encrypted internet texting and calling with a built-in earpiece)?

Thanks.

[matt2]

I cannot answer all of your questions at this time, but I have removed the cell modem in a birch model and I can make calls using SIP:

Librem 5 camera software

These were taken with just the torch light with the new white balance preset from the merge request above: [phone-birch] That was the birch model. Because most of Purism’s stuff is black (which is why I included the green and blue circuit boards), and black does not test white balance that well, I also took this picture: [book-ahggtt2c] I used the auto setting for most parameters. I probably could have dialed in a few things better.

I was testing the color balance on the built-in LED in that picture with another Librem 5.

When the kill switch is turned on, the modem is indistinguishable from being physically removed. This is a common use case, so I expect that the rest of the phone should work as normal. The cell modem’s firmware settings may be out of date if you ever put it back in, but maybe there will be a published procedure for fixing that at some point (currently you have to e-mail support to do this). Purism has said to put the kill switches in the off position (which is basically the on position in more basic terms) when updating the phone for this reason, but the updates seem to skip over the absent cell modem just fine.

[fsflover]

@user0

• If the cellular modem is removed, can the cellular killswitch be used to disable Lockdown mode while keeping the other two killswitches set to block WiFi/Bluetooth and Cameras/Microphones? (this could enable offline map access with GPS and other sensors)

Yes, this should indeed work.

[matt2]

Something to consider is a need for medical services, although I am not sure if that guarantees who does or does not show up when you call 911. If your phone never leaves the area, you could research the direct number for medical services for your area. VoIP should let you reach that. Of course, you would have to have WiFi service from where you are calling. So plan your home’s indoor and outdoor WiFi coverage accordingly.

Something to consider as a backup, VoIP providers for residential service force you to enter your home address for E911, which would work without a cell modem.

[Gavaudan]

And the fire department.

[matt2]

Also good to add, although in the case of fire, relying on VoIP is more risky, unless the phone also connects to the neighbor’s WiFi. Hopefully the smoke detector’s sensor type is the correct type for the type of fire that you have so that you can get an early exit. Because once the electrical breakers that the Internet service is on or the WiFi access point is on trip (assuming that you do not have UPSs on both), or the wires providing power or communication melt, VoIP is not going to be an option. Also, you need the usable WiFi coverage to extend to where you want to be safely standing during the fire. I am not sure how fire affects the propagation of WiFi signals, so the reach of the signal might not be the same during a fire. That is just pure speculation on my part, but I do know that the ionization from fire does some things to capacitive sensors.

[carlosgonz]

Well the Librem 5 it running the Modem in a alcatraz JAIL, so carrier do not have 100% access, but some. Moreover let is wait the libre firmware to L5 to improve this modem to security,safe.
Same JAIL too for Blobs firmware.
Purism GNUSTAR!

[irvinewade]

@user0

Could removing the cellular modem cause the Librem 5 to be warmer or cooler when in use?

Compared with the kill switch being used to switch the modem off, I would expect no difference in power consumption or thermals - but I suppose that is something that you could easily measure in order to verify.

@user0

Is Purism still considering a non-removable cellular modem

^{[citation needed]}

Obviously there are some of your questions that only Purism can answer. (You should really number your questions.)

@user0

I can no longer think of a single instance in which it would be safer to call emergency services than not.

I think that depends on the kind of area you frequent and the circumstances related thereto. If you visit, for example, a national park where there is mobile signal coverage but most definitely no WiFi, I can certainly envisage scenarios where calling emergency services will be A Good Thing™. You won’t be able to summon help from family, friends or neighbours - so you would be relying on a) keeping them informed of your planned movements and b) hoping that they react appropriately to rescue you (without calling emergency services) once they realise that something has gone wrong for you.

Slightly undermining my own point, there was a recent case in the US where a family died while out walking because they were unable to call emergency services (due to crap signal - but “crap signal” is guaranteed if you have taken the modem out).

In my own country your approach would be a bad trade-off: the countryside is more dangerous than emergency services. But, all good, everyone is free to make decisions for him/herself.

[user0]

@matt2

I cannot answer all of your questions at this time, but I have removed the cell modem in a birch model and I can make calls using SIP

Thanks for the info. That’s good to know.

@matt2

The cell modem’s firmware settings may be out of date if you ever put it back in, but maybe there will be a published procedure for fixing that at some point (currently you have to e-mail support to do this).

I have actually had the cellular killswitch set to block (or kill) the cellular modem since I received the Librem 5. When I receive the new SparkLAN WiFi Module that I ordered, I am going to remove the cellular modem for good. Thanks again for the info on this.

@matt2

Something to consider is a need for medical services, although I am not sure if that guarantees who does or does not show up when you call 911.

At this point, my trust is gone. Calling emergency services is a gamble that I’m not willing to take.

@matt2

assuming that you do not have UPSs on both

I do have UPSs for all of my important networking equipment (router, access points, swtiches, etc.).

@Gavaudan

And the fire department.

This is what I meant by asking family, friends, neighbors for help. If there was a fire in my neighborhood, my neighbors would call the fire department directly (located very closeby). For all medical emergencies, it makes far more sense to drive or be driven to the nearest medical facility (also very closeby).

@irvinewade

Compared with the kill switch being used to switch the modem off, I would expect no difference in power consumption or thermals

I was thinking that maybe a disabled cellular modem may act as a heat sink and that an empty pocket of air could become warmer than it otherwise would be. I also don’t expect to notice a difference, just thinking of the possibility and wondering if it is safe. It seems safe, so I will be removing the cellular modem when I receive my new SparkLAN WiFi Module soon.

@irvinewade

[citation needed]

I remember seeing a post on this forum in which someone from Purism mentioned that this was an option they were considering. I don’t remember which forum post off the top of my head, but it was probably about the Fir batch. I’ll try to find it and edit this post or make another one in response if I can.

@irvinewade

I think that depends on the kind of area you frequent and the circumstances related thereto.

Yes, I am only talking for myself. For all emergencies I can imagine, I would likely be in the company of others that themselves have cellular phone service. If absolutely necessary, others could make calls on my behalf, but I don’t find that likely to happen.

@irvinewade

In my own country your approach would be a bad trade-off: the countryside is more dangerous than emergency services.

Yes, this issue depends on the country. Obviously in the USA, there is a vast network of violent police officers armed with deadly weapons and little to no consequencies for publicly executing civilians. For the time being, that will always be something to factor in to emergency situations and whether that risk is worth it.

[user0]

@irvinewade

[citation needed]

@user0

I remember seeing a post on this forum in which someone from Purism mentioned that this was an option they were considering. I don’t remember which forum post off the top of my head, but it was probably about the Fir batch. I’ll try to find it and edit this post or make another one in response if I can.

I can’t seem to find the post that I remember. I may be misremembering, but I thought that someone from Purism like @Kyle_Rankin or @nicole.faerber mentioned internal discussions about this in a post in 2022. I think the context was that it would be easier for Purism to sell Librem 5 with non-removable cellular modem to intelligence agencies and similar entities that may require that. Like I said, I could be misremembering.

[irvinewade]

@user0

easier for Purism to sell Librem 5 with non-removable cellular modem to intelligence agencies and similar entities that may require that

It seems to me that that would really get away from the spirit of the Librem 5 i.e. making it impossible to remove also makes it impossible to upgrade.

And for one intelligence agency up against another … there is no such thing as non-removable. Right? I mean with the resources of a nation state, unsoldering a grid array and then using a suitable machine to solder on a replacement module (with compromised firmware) is doable?

Let’s not forget that some of these damned modules support Firmware Over The Air (FOTA), in which case it may not be necessary to mess around with removing modules. So you need to tame that first.

But, sure, if Purism can sell enough phones to intelligence agencies to justify creating the Librem 5 TLA Edition, go for it.

[irvinewade]

@user0

others could make calls on my behalf

Isn’t that unethical? That is to say, you are avoiding the risk of summary execution by not having a mobile phone and instead relying on someone else to take on that risk on your behalf. But we digress …

[user0]

@irvinewade

Isn’t that unethical? That is to say, you are avoiding the risk of summary execution by not having a mobile phone and instead relying on someone else to take on that risk on your behalf.

What I meant is that I wouldn’t necessarily stop someone from calling emergency services in cases of fires or similar events, but I also wouldn’t request that others make such calls on my behalf. If I have a medical emergency and family, friends, neighbors cannot or will not assist me in getting to a medical facility, then so be it. I can’t imagine that such a situation would be likely to happen, but I’d rather deal with it myself or die trying than to summon my own execution.

[Gavaudan]

It makes sense (sort of, I have to squint my brain) why you wouldn’t want to call the cops, but I don’t understand why you’d refuse to call for an ambulance or fire dept. Sounds like needless endangerment to me.

Also I wouldn’t advertise a refusal to call the cops to anyone who can identify you, it would make you a target for crime. Then if someone sees it happening they’re going to call the cops and send them your way anyway.

[user0]

@Gavaudan

I don’t understand why you’d refuse to call for an ambulance or fire dept. Sounds like needless endangerment to me.

I don’t feel the need to pay a monthy or yearly service fee for an activated SIM card that will go unused for the majority (or entirety) of my life. Everyone’s living conditions are different. If there is a fire emergency in my neighborhood, I know that a neighbor would immediately call the fire department. There’s no need for me to also have that ability, in my personal situation. Calling an ambulance would result in an unnecessary bill (I live in the USA), and there are plenty of friends, family, and neighbors that could drive me to a medical facility if I couldn’t do so. I have typically been the driver for others.

@Gavaudan

Also I wouldn’t advertise a refusal to call the cops to anyone who can identify you, it would make you a target for crime.

I consider this account to be annonymous, and this isn’t the sort of conversation that I spark up with strangers, but I understand your concern.

[Gavaudan]

@user0

I consider this account to be annonymous, and this isn’t the sort of conversation that I spark up with strangers

Right, but you may tell friends who tell friends and so on and eventually someone knows who shouldn’t.

Either way, I get where you’re coming from. Here’s hoping it doesn’t bite you in the ass.

[irvinewade]

And regardless of the opinions being expressed here, let us know how it goes from a technical point of view. I don’t think anyone expects you to have a problem after the modem has been removed but only you can confirm or refute this.

[user0]

1. After removing the cellular modem, my Librem 5 works just as it did with the cellular modem disabled using the killswitch.

2. Yes, it appears that the Librem 5 is designed to be fully functional with or without a cellular modem installed.

3. @dos answered this question saying that “resuming from suspend is completely unrelated to whether you use the modem or not” and recently made a post listing what there is still to be done for suspend to work properly. and I hope that my use-case is included. While I never got an answer on this, I think that the Librem 5 will eventually be able to wake/resume from sleep without a cellular modem for notifications from non-cellular applications (alarm clock, instant messaging, etc.). (Edited to emphasize that this question has been answered by @dos)

4. I have not noticed any difference in temperature after removing the cellular modem from my Librem 5.

5. The antennas are actually firm enough to hold their position without rattling around, and there is a small piece of foam on the inside of the plastic cover that is designed to hold them onto the cellular modem. With the cellular modem removed, the foam holds them in place and prevents them from making any noise.

6. With the cellular modem removed, it is safe to use the cellular killswitch, as described in answer 7.

7. Yes, without a cellular modem installed, the cellular killswitch can be used to enable/disable Lockdown mode. Since there is no Lockdown mode icon (yet?), you can swipe down from the top of the device to display the quick settings in order to see whether Lockdown mode is enabled or disabled. The rotation button toggles between Portrait and Landscape when Lockdown mode is enabled, and the rotation button toggles between On and Off (auto-rotate) when Lockdown mode is disabled. Using the cellular killswitch to disable Lockdown mode allows games and other applications to use accelerometer, gyroscope, and other sensors in offline mode without needing to enable the cameras/microphones. I don’t think there is any way to download maps for offline use yet, but once that feature is added, offline GPS navigation will also be possible.

While I was removing the cellular modem from my Librem 5, I also upgraded to the new SparkLAN Wifi card, and I love that I can do all of this to my phone.

[irvinewade]

Thanks for reporting back.

@user0

I love that I can do all of this to my phone.

Exactly right. One of the concepts is that you own your phone. You get to decide what goes in your phone, whether that’s taking out the cellular modem or putting in a WiFi card.

[dos]

@user0

While I never got an answer on this, I think that the Librem 5 will eventually be able to wake/resume from sleep without a cellular modem.

It is already able to resume without a cellular modem (via buttons, USB-C, RTC, …). Do you have some specific wakeup source in mind?