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Observing my cellphone switch towers

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Re: Observing my cellphone switch towers

#81

Post by dylan604 »

hansor wrote: post #39
masklinn wrote: post #27

Earlier quoted context omitted.

> How do i do this myself now? As the essay notes, it's through TelephonyManager on Android. On iOS it used to be possible through CoreTelephony private APIs, but I think Apple cracked down on these a few years back and either removed them entirely or locked them down behind entitlements, as they were getting abused by analytics frameworks.

There are plenty of free android applications showing you your local cellular info with CID LAC, CI etc. For example "Signal strength" APK. It's just matter of time until you will find one with logging and export ability. You can always write it down with pencil :)

Naw, this is HN, so it'd be more like take a screen shot, upload to some ML tool you cooked up in a weekend that OCRs the data, loads it into a NoSQL database with the cotnent presented in the latest fad JS framework using Lamda functions or some other cloud hosted CI/CD blue-green deployment to support both users.

Re: Observing my cellphone switch towers

#82

Post by dTal »

qb2021 wrote: post #53

At this one industrial customer I visit every week for a full day, my Verizon cell phone date/time time will suddenly change back by 19 years, six months, and some days (I don't have the exact value). This has been going on for almost a year. My pet theory was that law enforcement turned on a stingray nearby back in 2020, it came up with a default date of 1/1/2001, and has been running ever since. Steel building with…

Could it possibly be because the time is being set from GPS, somewhere in the stack? The 19-and-a-half year offset is spot on.

https://en.wikipedia.org/wiki/GPS_week_number_rollover

Re: Observing my cellphone switch towers

#83

Post by Kipters »

qb2021 wrote: post #53

At this one industrial customer I visit every week for a full day, my Verizon cell phone date/time time will suddenly change back by 19 years, six months, and some days (I don't have the exact value). This has been going on for almost a year. My pet theory was that law enforcement turned on a stingray nearby back in 2020, it came up with a default date of 1/1/2001, and has been running ever since. Steel building with…

Happened to me too, but maybe worse: two minutes behind

This was when SMS were still widely used, so that made for very messed up chats since received messages carried the correct timestamp

Re: Observing my cellphone switch towers

#84

Post by vbsteven »

gtsop wrote: post #57
vbsteven wrote: post #20

On a related note, this same mechanism can be used as a fallback for GPS to determine device location. I have worked on an IoT device with builtin SIM in the personal alarm space. Often when a device is indoors no GPS fix can be found, but the GSM module can report all celltower ids in range with signal strengths. These can be used to triangulate the device location. Google has an API for this where you can pass celt…

> I have worked on an IoT device with builtin SIM in the personal alarm space Are there any resources to that project? Comercial or free?

It was a commercial project for a client I cannot link. Nothing exotic though. Just a little smartwatch-type device with soc/mcu/gsm/gps, 1 button and a led display.

It only had 2G which is already retired in some countries and I don’t know if they’re doing an 3/4/5G refresh.

A fun space to work in though. A space where a small bit of tech can save lives and where tracking is actually helpful.

Edit: but stressful as well. As bugs in the code or platform can lead to people in distress not getting the help they need.

Re: Observing my cellphone switch towers

#85

Post by vbsteven »

Zenst wrote: post #44
kqr wrote: post #36

Earlier quoted context omitted.

> I assume this is one of the many things Google is doing with their fleet of Streetview cars. ...and Google services-enabled Android smartphones. Source: I have used a single access points in many locations across the country in a relatively short period of time. When there's no GPS fix, Google always thinks I'm where I just was. (And there are no Streetview cars in some of these locations.)

Or your Wifi MAC gets tagged by a streetcar at one location, you move and google still things your at the old location. Had that, they even have way to feed that back iirc and was able to get that updated without a driveby of a streetcar. Note this was over ten years ago and WiFi density has increased.

It can still easily happen in 2021 simply by moving an existing WiFi AP to a new location where the WiFi space isn’t crowded.

Re: Observing my cellphone switch towers

#86

Post by bogomipz »

This was a good read. I laughed out loud when I read the notes column of their cell technology matrix which listed Mr Drummond and Gordan Gecko for 0G and 1G respectively.

I can also highly recommend the book "High Performance Browser Networking" by Ilya Grigorik referenced by this post. Although it's almost 8 years old most of is still very relevant. Although it would be wonderful if he would update it to reflect changes in TLS and 5G.

I also really liked the layout and fonts on this person's site. It has an almost 'zine aesthetic. Very easy on the eyes. Does anyone know what they might be using to produce this?

Re: Observing my cellphone switch towers

#87

Post by drvdevd »

hansor wrote: post #38

It's quite hilarious seeing bunch of skilled and intelligent hackers being excited regrading process known as "Handover" :) It is well known, and well documented in every single book in subject... Worth to mention that there are 3 types of handovers: - Intra-relations: user can be switched between various cells at same tower. - Intra-relations but with handover to lower technology (let's say when 4g is not available[…

The most interesting part of this article IMO is how the author built handover visualizations with unprivileged code and explained what was exposed in the API on Android vs iOS that was needed to do this. And they're quite good.

Re: Observing my cellphone switch towers

#88

Post by vbsteven »

hansor wrote: post #38

It's quite hilarious seeing bunch of skilled and intelligent hackers being excited regrading process known as "Handover" :) It is well known, and well documented in every single book in subject... Worth to mention that there are 3 types of handovers: - Intra-relations: user can be switched between various cells at same tower. - Intra-relations but with handover to lower technology (let's say when 4g is not available[…

Handovers can exist on a higher level as well. 10 years ago there were calling apps that could handover a WiFi VoIP call to the gsm network (not using voip but actual gsm) when the WiFi goes bad and later switch the same call back to WiFi.

Re: Observing my cellphone switch towers

#89

Post by efraim »

the8472 wrote: post #47
heelix wrote: post #45

Something like this would make it pretty easy to spot one of those stingray devices, I bet. Cell towers tend to stay put, so mapping out an area would go quick. Were a new 'tower' show up in an odd spot -- there may be shenanigans at hand.

the GPS location is reported by the tower, so nothing is stopping a mitm device from spoofing that too

The location is taken from an online database based on cell id. It's not clear where most of them get their data but services like wigle and mozilla use crowd sourcing of signal strengths so they might be a bit off. Not as accurate as the ones in the article I would think.

Re: Observing my cellphone switch towers

#90

Post by [deleted] »

bogomipz wrote: post #86

This was a good read. I laughed out loud when I read the notes column of their cell technology matrix which listed Mr Drummond and Gordan Gecko for 0G and 1G respectively. I can also highly recommend the book "High Performance Browser Networking" by Ilya Grigorik referenced by this post. Although it's almost 8 years old most of is still very relevant. Although it would be wonderful if he would update it to reflect ch…

[deleted]
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