Mobile phone location tracking via cell towers - 4G vs 5G

Privacy Questions
1

Are there any privacy implications for mobile phone location tracking of using 4G vs 5G?

Let’s assume I’m using a phone which doesn’t report my position (derived from GPS, wifi triangulation, etc) to someone like Google or Apple. My location is still being tracked by the cell network because my phone is connecting to nearby cells and the phone identity is tied to my identity.

My understanding is that 5G cells are geographically smaller than 4G cells, so does this mean that if I have a 5G-capable phone and a 5G-capable SIM, the cell location tracking narrows my position down more on 5G than on 4G?

Does it make a difference if I set my phone to use 4G only even if it and my SIM are 5G-capable? Or if I deliberately use a 4G-only SIM or stick with a 4G-only phone?

Does it make a difference if my mobile network provider is using 5G StandAlone vs 5G Non-StandAlone?

As 5G becomes more prevalent, will the same smaller 5G cells also be used as 4G cells and thus the possible privacy advantages of 4G will reduce?

Does anyone have any figures for the precision of tracking based on 4G and 5G cells?

2

I would recommend watching this recent video by The Hated One. It’s quite informative and addresses most of your questions.
The TLDR is:
A) Yes, 5G cell towers are more dense and therefore can determine your location more precisely, especially in urban areas.
B) Yes, in 4G-only mode, your phone will only communicate with 4G cellular radios except when making emergency calls.
C) It is unlikely that non-urban areas will ever have dense enough coverage to greatly improve tracking precision from what is possible with 4G, which is already quite precise. Lower frequency 5G will likely be used in these cases.
D) It is briefly mentioned in the video I posted, but my understanding is that 4G is somewhere in the 10-100 meter range, obviously varying wildly depending on the density of cell towers. 5G, on the other hand, may (in some circumstances) be accurate down to sub-1 meter.

3 Likes
3

Mobile phones use time division multiplex access (TDMA) to access their towers. At least they did for 2G, 3G and 4G and I believe they still do for 5G. This means they need and have accurate timing for a round trip signal between the phone and the cell antenna. (Actually more than just TDMA as they also use frequency division and, I believe, code division as well. But for distance from cell antenna the TDMA portion is what we need to consider.)

Because time is distance (based on the speed of light and radio waves) they know the distance from the cell antenna to your phone very accurately.

An exception to accurate distance is in rural areas: They assume a maximum distance and if you are beyond that then the TDMA time slot wraps around and they think you are much nearer the tower than you really are. In urban and suburban environments you won’t run into that issue so they have accurate distances.

If you are visible to only one antenna which typically has a 120° coverage they will know what arc you are on (general direction and distance from antenna). If visible to two cell antennas they will know one or two possible locations for you. If visible to three or more cell antennas they will know your location very accurately, often to within a few feet/meters. Close enough that if you call emergency services they will know exactly where to respond.

So it doesn’t really matter if you are on 4G or 5G, they know where you are.

Again, exception for very rural areas where you phone is only visible to one cellular antenna as they know only the general direction and their time slot may be off by some multiple of the maximum assumed distance. In that case you could be miles from where they think. This is a problem search and rescue teams deal with all the time.

Also, 5G is just the over the air protocol. The actual frequency bands they use affects the coverage and the data rates. The higher the frequency used the smaller the coverage and the higher the data rate. When 5G was released there was bandwidth allocated at much higher frequencies for it but nothing stops the cell companies reusing the older frequency allocations. Cell companies can use the new higher frequency allocations in urban areas to service more people and/or provide much faster speeds. But in suburban and rural areas they may use 5G protocols on the frequencies former used for 2G, 3G or 4G service and get about the same coverage area as the old service they replaced.

1 Like
4

Thanks, both of you.

I had seen that Hated One video mentioned but hadn’t watched it as I thought it might be a bit click-baity or extreme based on the title. I’ve now watched it though.

I am a bit shocked to find that 4G can track me so precisely. I could have sworn I’d heard figures like quarter or half-mile accuracy mentioned in the past in urban areas. Are the figures you’ve both mentioned relevant even when the phone is not actually making a call? I suspect they are, given that data is “always on”. (I almost never make standard phone calls, preferring messenger apps via a data connection instead.)

Can anyone recommend a trustworthy write-up on mobile network privacy issues? I could ask some follow-on questions here, and I might do, but it would be good if I could do some background reading first. (To take one example, I see in the comments on the THO video various contradictory claims about whether airplane mode does or doesn’t turn the radios off and what the phone broadcasts. I don’t particularly trust random comments on YT videos, but presumably there are some facts here and it would be nice to know what they are.)

I believe 2G still works in my country, although 3G is either dead or dying. Could I evade the precise location tracking of 4G by using a 2G-capable SIM and restricting my phone to 2G? I appreciate I wouldn’t get anything like usable data, but it would let me make and receive standard phone calls in emergencies and maybe (following THO’s suggestion) I could use public wifi for less urgent stuff. Based on OldGuy’s post, maybe even 2G is subject to the same triangulation though.

5

2G (GSM for most of the world) uses TDMA and so can determine the distance between the phone and the cell antenna too.

Data on or off makes no difference. Making a call or not makes no difference. The timing measurement is at a RF interface level. If the phone is showing any bars the cell provider’s antenna knows the distance.

And if you are not in airplane mode, even if you have no bars the phone is still trying to connect to a mobile network and you don’t know how far it has gotten and might have the timing detected with insufficient signal to noise ratio to actually allow calls or data.

Basically, your phone is a tracking device. If you want to carry it around with you and not be tracked you need to do as the fellow in the video and disable all phone capabilities. In the case of the video he has no SIM and leaves it in airplane mode.

1 Like
6

Don’t worry about cellular tracking. When you get to that threat model anyway you shouldn’t be using phones or staying in anywhere that has modern infrastructure (even in rural areas) due to CCTV cameras and other surveillance tech.

Also remember that you might not have a phone with you but your companion might not be savvy enough to understand the situation you are in and bring a phone without you knowing.

3 Likes
7

5G is more secure than 4G, though a little bit less private.

8

Yes, mmWave can get your position down up to a few centimeters.

9

Thanks guys! I don’t like what I’m hearing, but better not to be living under a false but comforting illusion, I guess.

Don’t worry about cellular tracking. When you get to that threat model anyway you shouldn’t be using phones or staying in anywhere that has modern infrastructure (even in rural areas) due to CCTV cameras and other surveillance tech.

I think I get where you’re coming from, but I’m still not comfortable just letting this go.

Yes, “they” can track me via CCTV and so on and that (IMO) sucks. But it doesn’t feel like we’re quite at the point where this is absolutely automated yet - it feels like something that mostly requires effort (some sort of explicit investigation is underway) to collect footage (some of which may come from private CCTV) and analyse and collate it. It’s also not something I can really do very much about, short of wearing one of those fancy weird face masks or similar.

But I can control whether I voluntarily walk around with a tracking device which provides sufficient accuracy for some company to say things like “hmm, SteveR seems to be visiting that new bar down the street a lot” and adding this to my advertising profile, or my medical records.

It’s one thing for me to be unavoidably monitored by CCTV and the like, another to cooperate and hand my precise location on a plate with watercress round it not just to the authorities but also to the mobile networks and anyone they care to sell that data to.

When I was under the impression I was being tracked to within a quarter mile or so, it didn’t feel too bad. Statistically I could be linked to events being investigated (protests, crimes, whatever), which I didn’t like but could accept. What I really don’t want is to feel that I am being tracked down to the individual businesses I visit and so on, entirely automatically, and by commercial entities trying to profile, manipulate and influence me.

I’m going to have to think about this. I am reluctant to give up the convenience of always-on data, but now I know how precise even the 4G tracking is I may be forced to accept some inconvenience. I’ve had some lurking thoughts along the lines of “it is not healthy for me to feel I must have my phone with me at all times and be in contact 24/7” anyway, so maybe this will be the kick up the backside I need to re-evaluate this.

I don’t know if it needs saying here, but just for what it’s worth: I don’t have anything to hide, my real-world life is even more boring and conventional than my on-line life, but I utterly resent being tracked despite that.

3 Likes
11

Did you ever hear of nitro phone. You oughta check it out. They have more than just phones. I’m new on this journey but if I’m not mistaken they have companies out there that aren’t your regular cell network. I’m not at that point yet but I’m learning as much as I can before we move.

12

Geofencing warrants can be an issue, that I can definitely understand, and it can drag you into surveillance.

I have this impression that you are driving and since you are driving already and technically should not be using your phone, consider having a Faraday cage container of sorts inside your car during your commute.

If I may derail the conversation a bit, how do you deal with the license plate readers?

1 Like
13

NitroPhones are just rebranded Pixel devices that come with GrapheneOS.

4 Likes
14

Or just turn on the airplane if you’re using a properly secured phone.

4 Likes
15

Did you ever consider that some people might want a device like that. One that is already set up. You act like that’s a bad thing. I see no reason for your comment except that you didnt think to suggest it to the OP. . I thought it was pretty cool that a company took the time to build these phones with privacy in mind that are fully functional out the box.

Some people might be concerned about the same things you are but don’t where to start. But they heard about it and sometimes thats all it takes.

1 Like
16

Saying they took the time to build the phones with privacy in mind is a stretch. A 50% markup is blatantly predatory, especially considering they’re just using off-the-shelf phones with GrapheneOS installed. They’re taking advantage of consumers who want the benefits of GrapheneOS but either don’t know how simple it is to install by themselves or don’t want to deal with it.

3 Likes
17

You could look at THO sources listed under the video mentioned by @phnx . There are 18 and one of those could give the info you seek.

2 Likes
18

Thanks all.

@LukewarmNinja - I will check out the sources on the THO video - I didn’t notice that there were any before.

@Lukas - airplane mode is definitely on my list of things to consider now. I don’t want to go too extreme and I am not actively trying to hide, so I’m wondering if there’s some kind of better compromise before I resort to that. For example, if I got a prepaid cash SIM (which I have held off on because it’s considerably more expensive than a contract for my specific requirements), that might break the link as far as non-statistical commercial surveillance goes - although I’d perhaps need a new cash-paid phone too. The authorities (and the mobile network) would be able to statistically infer that the new phone+SIM were mine given they spend most of their time in my house, so I wouldn’t want to be carrying this phone+SIM with me while out committing crimes. But I suspect that this statistical link wouldn’t be good enough for anyone to attach my movements to my real identity for advertising purposes and general commercial profiling. So it might be enough to avoid the really annoying and intrusive daily surveillance as long as I’m not actually of interest to law enforcement.

@HauntSanctuary - I actually use public transport and walking most of the time. I hadn’t even thought about it, but I agree that license plate readers would be a big concern if I were driving and would mostly make any attempt to avoid cell tower based tracking futile.

@Cntrygirlatheart - Thanks for the link. NitroPhone looks a bit outdated though, the Pixel 4a is no longer supported by Graphene or receiving Google security updates. I had a look over the page to see if they said anything specific about avoid cell tower tracking via some clever technique or alternate mobile network, but I missed it if it was there.

2 Likes
19

I understand that it’s certainly comforting to view it that way, but I am afraid it simply isn’t true. It’s generally trivial to establish such a link. I recommend reading this recent article by Joseph Cox. Although it is about location tracking, not cellular tracking, the implications are effectively the same.

In all fairness, that link is outdated, and they do sell the most recent Pixel devices flashed with GrapheneOS. Though I won’t provide a link out of principle.

Anyone considering a NitroPhone should really take a look at the official GrapheneOS web installer here. It really can be installed by anyone with no technical knowledge.

2 Likes
20

@phnx - thanks, but unfortunately that link seems to be for paid subscribers only. Could you give me a brief summary? From the bit I was able to read for free, it does look rather like something only a relatively “dedicated” adversary is likely going to do - not that it’s necessarily incredibly difficult, but it isn’t at quite the level of triviality that makes it natural for commercial profiling. The abortion context here suggests there is either a legal or moral angle motivating whoever is doing this correlation. Obviously I haven’t read the full thing though, so I appreciate I could be wrong.

Point taken with the NitroPhone. I am a cheapskate and technically inclined enough to install Graphene myself, so I would never pay for their service anyway, regardless of my views on it. But it’s at least nice to see they have kept up to date.

21

Sorry, that was an oversight on my part. Basically, this is location data that is being sold commercially by data brokers. So while in this case it’s a tool being used for warrantless tracking by LE, there is nothing stopping other interests from purchasing the data. All they would have to do is check the location of the device at night (a feature built into the software the article is about) to de-anonymize the individual.

The EFF has a good (non-paywalled :wink:) article about the Myth of Anonymous Data. To quote that article, “One study from 2013 found that researchers could uniquely identify 50% of people using only two randomly chosen time and location data points.”

To be clear, I’m not opposed to the service they offer, but rather to the fact that their prices are highway robbery.