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Did 5G kill the IMSI catcher?

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Re: Did 5G kill the IMSI catcher?

#91

Post by elric »

1oooqooq wrote: post #19
lxgr wrote: post #3

I've always been wondering: Is there a SIM card configuration flag that allows telling the phone to never even attempt an attach using a given technology? This would allow leaking identifiers (at the cost of greatly reducing roaming coverage, at the moment), attaching to spoofed networks (for 2G, which does not have mutual authentication) etc.

if you pay the google tax for a pixel, you get a convenient 2G toggle. if you don't have an extra $400-900 and buy a cheaper android, you get to dial # #4636# # (hn screws asterisks, look it up) them go into phone info, select each sim radio and change the drop down (and hopefully you know all the standards by all names to make the right choice. hint 5G is NR there)

Is there a name for those ##number## codes? It's been years since I had to use one of them to fix some random issue on a phone.

Re: Did 5G kill the IMSI catcher?

#92

Post by ryukoposting »

donnachangstein wrote: post #45
buckle8017 wrote: post #40

Earlier quoted context omitted.

Verizon has actually deployed mmWave 5G fairly widely.

Sprint deployed WiMAX (remember that?) fairly widely, lot of good that did them. mmWave is as dead as dead. The cellular Betamax. iPhone 16e (the everyman's iPhone) doesn't support it, and neither did the SE before it. VZW will be converting those base stations into birdhouses in 5-7 years.

"Cellular Betamax" would suggest someone knowingly used it, and a handful of people actually liked it and committed to it.

Re: Did 5G kill the IMSI catcher?

#93

Post by vv_ »

flotzam wrote: post #88
vv_ wrote: post #83

Earlier quoted context omitted.

If you force 4G and 5G only, you are likely to lose access to mobile calls. VoLTE interoperability is still lacking, and this issue is unlikely to be resolved without intervention from a standards organization mandating interoperability and default settings. Unfortunately it will only get attention when somebody can't do an Emergency Call.

Emergency calls bypass the network restriction. I don't see it documented for GrapheneOS, but https://source.android.com/docs/security/features/cellular-s... states 'Android allows users to disable 2G at the radio hardware level on any device that implements the capability constant, "CAPABILITY_USES_ALLOWED_NETWORK_TYPES_BITMASK". This stops a device from scanning or connecting to 2G networks. Note: Emergency calling…

I guess it makes sense as Emergency Calls are highly regulated.

It still applies for normal calls though. I guess this is why major smartphone operating systems do not allow you prevent 2G/3G registration.

Re: Did 5G kill the IMSI catcher?

#94

Post by est »

flotzam wrote: post #71

> The only simple thing you can do, that can have an effect, is to set your network priority to 5G-SA – but most phones don’t support this feature. 'add support for "5G only" and "4G or 5G only" modes in addition to our existing "4G only" mode' - https://grapheneos.org/releases#2025022700

for android phones, type `*#*#4636#*#*` in dial, you can choose phone network.

btw 4636 means INFO.

Re: Did 5G kill the IMSI catcher?

#95

Post by maxsilver »

NavinF wrote: post #43
jorvi wrote: post #26

Earlier quoted context omitted.

5G beamforming is not that accurate a proxy signal, and mmWave is phone vaporware, instead only significantly used for point-to-point connections. Line-of-sight requirements make it dead in the water for anything else.

> mmWave is phone vaporware Is it? I've definitely seen "5G UW" show up on my 15 Pro Max in the bay area. Att and Verizon are slowly expanding mmWave

"5G UW" is good service, but it's not usually mmWave. It's primarily mid-band stuff, usually Band n77 (3.7ghz C-Band)

It's usually good, but that's primarily because Verizon is going a good-ish job (in Michigan, at least) of deploying it densely in smaller neighborhood/urban cell sites (2x to 3x site density over traditional PCS-spaced cell towers). It's basically Verizon's version of what Clear was supposed to be doing with WiMax.

Notably, C-Band is not mmWave. mmWave bands start at like the 24.2ghz+, way way higher up the spectrum band.

If your phone reads "5G UW", there's like a 95% chance you aren't on mmWave, you are on n77 / C-Band / 'mid-band'.

Re: Did 5G kill the IMSI catcher?

#96

Post by maxsilver »

wtallis wrote: post #69
cyberax wrote: post #52

Earlier quoted context omitted.

mmWave is going to be useful in places like stadiums or large arenas, though. It works wonders in these kinds of applications. WiMAX never really worked well at all.

Stadiums are pretty much the only place where mmWave in phones makes sense. For the other 99.99% of usage, it's an expensive power-hungry extra radio that doesn't work. mmWave 5G is mostly a sunk cost for Verizon, and largely irrelevant to everyone else.

> Stadiums are pretty much the only place where mmWave in phones makes sense.

And Airports, and Parks, and Ampitheateaters, and Malls, and Theme Parks...

mmWave isn't a general solution, sure. But mmWave is great for anywhere crowded enough to benefit from a DAS setup, and there are a lot of DAS setups around.

Re: Did 5G kill the IMSI catcher?

#97

Post by huslage »

lxgr wrote: post #58
huslage wrote: post #54

Earlier quoted context omitted.

Correct, your phone needs to actually re-connect between the two networks. It's a whole new session and you can't handover between 5G SA and 5G NSA/LTE networks. There are some configurations that make this not much of an issue, but technically they are totally different networks.

You can definitely hand over sessions between 5G and 4G (and by extension 5G NSA, which essentially is 4G from a signaling point of view).

It's not a handover in the sense that you're actually creating a second connection to a different network. It's more akin to roaming than a handover.

Re: Did 5G kill the IMSI catcher?

#98

Post by adithyassekhar »

est wrote: post #94
flotzam wrote: post #71

> The only simple thing you can do, that can have an effect, is to set your network priority to 5G-SA – but most phones don’t support this feature. 'add support for "5G only" and "4G or 5G only" modes in addition to our existing "4G only" mode' - https://grapheneos.org/releases#2025022700

for android phones, type `*#*#4636#*#*` in dial, you can choose phone network. btw 4636 means INFO.

>btw 4636 means INFO.

I've been doing that all these years and never thought of that! You learn something new everyday. For people who don't know, it's T9 dialing.

Re: Did 5G kill the IMSI catcher?

#99

Post by dfc »

vv_ wrote: post #77
jeroenhd wrote: post #6

Criminal IMSI catchers are pretty much dead, but with the aid of carriers law enforcement can still use similar technology even with full standalone 5G networks. I don't know how often unauthorized IMSI catchers are used in the wild, but I doubt it's a relevant percentage of the total amount of IMSI catchers out there. Thanks to mmWave and beam forming, 5G allows operators to practically track you down to the exact c…

> Furthermore, depending on how willing the firmware of your modem is, the signal used to transfer GPS coordinates to the carrier for emergency response situations can also be triggered remotely by carrier hardware. It should be feasible for an operator to issue a command to the (e)UICC (SIM) in the phone to fetch the current location from the modem and send it back via SMS. At least this was the case for a relativel…

What command command can you send to the UICC to get the location? I did not think any phones honored those requests from the SIM.

Re: Did 5G kill the IMSI catcher?

#100

Post by taneliv »

elric wrote: post #91
1oooqooq wrote: post #19

Earlier quoted context omitted.

if you pay the google tax for a pixel, you get a convenient 2G toggle. if you don't have an extra $400-900 and buy a cheaper android, you get to dial # #4636# # (hn screws asterisks, look it up) them go into phone info, select each sim radio and change the drop down (and hopefully you know all the standards by all names to make the right choice. hint 5G is NR there)

Is there a name for those ##number## codes? It's been years since I had to use one of them to fix some random issue on a phone.

USSD and MMI, see for example https://en.wikipedia.org/wiki/Unstructured_Supplementary_Ser... . On a quick glance the references did not seem to list what codes are usually available, so just search "ussd code list" or similar.
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