Missing 4G only mode toggle in the SIM settings

oci3o

Hey all,

Not sure if I've missed something from recent release notes (I've quickly checked the last 5 or so release notes), I've done a fresh setup of my GOS setup, however I've noticed in Settings > SIMs > SIM, I no longer have the option to force 4G only mode?

I'm on the most recent stable build, but I'm not seeing it inside the options?

Phone is a Pixel 9 Pro XL with a physical SIM.

Thanks

itsjpb

oci3o LTE is a subtype of 4G, and as such i imagine the 'LTE only' option is a different title on the same function

oci3o

itsjpb It used to be a separate option, so you'd have a list of modes such as 4G and 5G only mode, 4G only mode etc, but it seems to be missing lately.

wizoatk

oci3o

Something changed and now some carriers can hide this option.

You should be able to change the preferred network type with the *#*#4636#*#* dialer code and then selecting Phone information v2 (or Phone information). Or you could try an app like ForceLTE.

oci3o

wizoatk Just forced it using the way you suggested, thanks :)
Not sure why its not an option in the settings however.

wizoatk

oci3o

The simple answer is that you and your chosen carrier have a difference of opinion about what options the end user should have access to. The SIM options UI is dynamic. For example on my primary phone, two out of three SIMs still have the preferred network option in the Settings UI. The third SIM has that option hidden. That same behavior exists on Stock OS. It's not obvious where GOS will end up in either the short or long term with respect to specific carrier overrides.

GrapheneOS

wizoatk This won't work correctly. It doesn't save it in a way that's as persistent as the normal setting. Using an app isn't going to work properly and should not be done.

GrapheneOS

oci3o GrapheneOS is meant to ignore carriers disabling support for changing the cellular network mode but the feature was recently lost due to changes to how we implement device support. It has been added back for the next release. The change you made in the debug menu isn't going to persist properly and will get reset.

r134a

GrapheneOS Might i borrow some of your knowledge that is somewhat relates to this topic?

Yesterday i've came accross an app (Privacy cell, which indicated within the app that a device connected with 4g isn't secure from stingray IMSI mitm attacks, and while connected with 5g it claims the device is 'secure' against stingray IMSI attacks.

I've already found part of the answer here, that neither 4g and 5g aren't 'secure' against IMSI catchers, but the paper is dated 2 years back:
https://arxiv.org/abs/2405.00793.

I'm mostly in airplane mode with WiFi-calling routed through VPN.
For the times i need to connect to cellular towers, unless 5g is/becomes significantly more secure than 4g, i'd prefer staying on 4g only as i believe in general the triangulation 'range' is significantly 'less accurate' than 5g, depending on environment etc (urban, city, ...)

What is the case as of date? And what would be your recommendation for me or people like me with a threat model u can derive from my writing?

Thank u

de0u

r134a For the times i need to connect to cellular towers, unless 5g is/becomes significantly more secure than 4g, i'd prefer staying on 4g only as i believe in general the triangulation 'range' is significantly 'less accurate' than 5g, depending on environment etc (urban, city, ...)

Is there detailed information about the degree of the difference?

r134a

de0u Very good question, admittedly this is an assumption i made based on reading about this separated over several years. It was quite a search to find a single source that could motivate that claim.

I believe these 2 papers could motivate that claim:

https://pmc.ncbi.nlm.nih.gov/articles/PMC9268850/
https://arxiv.org/html/2209.01183v3

Disclaimer, i'm not a RF engineer, so my assumption could be based on interpreting data wrongly because lack of some specific terminology etc.
I believe these papers could motivate the claim i made, however someone more knowledgeable about this specific topic reading these papers could perhaps prove otherwise. In that case i guess i ride Cunningham’s law.

de0u

r134a I believe these 2 papers could motivate that claim:

https://pmc.ncbi.nlm.nih.gov/articles/PMC9268850/
https://arxiv.org/html/2209.01183v3

I glanced at the abstracts. To my eyes those both appear speculative, discussing things that carriers might do someday (one of them mentions 6G).

Even though there may be solid theoretical reasons why 5G localization could be much more precise and may be in the future, personally I would not conclude that there is a "significant" difference in current networks (my hunch is that the difference at present is very close to zero).

r134a

de0u i still believe that 5G networks have higher base station density and more accurate timing information, thus yielding higher location precision, in a nutshell.

When i have some more time i'll try to research it some deeper, perhaps papers that performed tests on 4g specifically and 5g specifically, so they can be compared.

If i find something, i'll post it here.

de0u

r134a I still believe that 5G networks have higher base station density and more accurate timing information, thus yielding higher location precision, in a nutshell.

As long as we're discussing beliefs, my personal belief is that a lot of 5G carriers emanate from a pre-existing 4G cell site, with part of the site's frequencies refarmed from the one protocol to the other. Over time, for sure, the plan is to add more/denser cell sites using the higher frequency bands, but that takes more time and money than refarming some of a site's spectrum to provide some users faster download speeds some of the time.

r134a When i have some more time i'll try to research it some deeper, perhaps papers that performed tests on 4g specifically and 5g specifically, so they can be compared.

If i find something, i'll post it here.

Great!

r134a

de0u I've found this paper:
https://pmc.ncbi.nlm.nih.gov/articles/PMC10504288/ which performed a test on a deployed 5g Vodafone network in Milan, Italy, and concluded that it is possible to localize with an accuracy of approx 8-10m.

I didn't read it fully though, just skimmed through it fast. On first glance the paper doesn't really compare it to 4g standards, so it is not clear from that specific paper if there is a significant improvement.
if i come across a test on the 4g network that concludes it's possible to localize down to say 50m at best, would that suffice to conclude its a 'significant' difference?

Probably9857

r134a if i come across a test on the 4g network that concludes it's possible to localize down to say 50m at best, would that suffice to conclude its a 'significant' difference?

If so, would that conclusion also apply to the actual locations and networks where you use your device?

r134a

Probably9857 If so, would it be reasonable to expect from me to perform these tests on all locations and networks i use my device, periodically, to be able to answer that question?

At the time, perhaps or perhaps not, depending on location. As time goes on, gradually, probably so.

de0u

r134a I've found this paper:
https://pmc.ncbi.nlm.nih.gov/articles/PMC10504288/ which performed a test on a deployed 5g Vodafone network in Milan, Italy, and concluded that it is possible to localize with an accuracy of approx 8-10m.

What I see there (admittedly based on a fast read):

At present 5G does not localize to 8-10 meters,
The researchers propose some techniques that someday might localize to that precision.
I think the techniques involve active participation (computation) on the device. If so, then involuntary precise localization by carriers is not part of that picture.

Ladida

oci3o

Yes exactly