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0 pointsChuckNorris892y ago0 comments

The question is how accurate is cell tower triangulation?

0 comments

It depends on the area. In very dense areas, it can be more accurate than you expect. It's also possible that they triggered a GPS response that told them rather precisely where the phone is.

I'm only speculating, of course.

Summershard2y ago

A few years ago, when I was studying, my friend and I did a project on that in Xamarin. It took us two evenings, and the accuracy was 300 meters at worst, and 30 meters at best. It's worth noting that this was in a larger city.

So, if two students can achieve even 30 meters accuracy in two days, big telecom corporations will certainly do better in a few decades.

EDIT: By the way, it wasn't only triangulation but also signal strength change analysis. It wasn't as serious as it sounds, there are formulas already made for calculating that.

autoexec2y ago

In the past, ~1 mile. One of the complaints people had about 5G was that it could make it much more accurate. Accurate enough to find a house or someone's location with it. It works because 5G needs towers all over the place to function.

adamparsons2y ago

Did the friend park the car out the front of his house, with a license plate that would have been shared by the sister? In the suburbs you don’t need to be overly precise, do a drive by and stop at the house with the car?

singleshot_2y ago

E911 says the PSAP has to be able to get within 100m iirc

trollied2y ago

Phones don’t just use triangulation. Modern smartphones will also use GPS (A-GPS).

miohtama2y ago

This is about asking the cell network where the phone is. This is not about asking the phone where the phone is.

JohnFen2y ago

I think the question was "how did the phone company know the location", and GPS may be part of the answer.

In the US, E911 requires all phones to be able to report their physical location. Phone companies may use this ability to respond to police location requests. I don't know one way or another, but it seems likely.

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mcpackieh2y ago

They won't use that if the GPS / "Location" service is turned off. But the cell network still knows where you are anyway, within ten meters or better. The FCC asks for z-axis accuracy within 3 meters; good enough to determine what floor of a building you're on (for E911 purposes.) 5G Rel 17 can supposedly locate people within a meter.

j / k navigate · click thread line to collapse

0 comments

JohnFen2y ago

It depends on the area. In very dense areas, it can be more accurate than you expect. It's also possible that they triggered a GPS response that told them rather precisely where the phone is.

I'm only speculating, of course.

Summershard2y ago

So, if two students can achieve even 30 meters accuracy in two days, big telecom corporations will certainly do better in a few decades.

EDIT: By the way, it wasn't only triangulation but also signal strength change analysis. It wasn't as serious as it sounds, there are formulas already made for calculating that.

autoexec2y ago

adamparsons2y ago

singleshot_2y ago

E911 says the PSAP has to be able to get within 100m iirc

trollied2y ago

Phones don’t just use triangulation. Modern smartphones will also use GPS (A-GPS).

miohtama2y ago

This is about asking the cell network where the phone is. This is not about asking the phone where the phone is.

JohnFen2y ago

I think the question was "how did the phone company know the location", and GPS may be part of the answer.

1 more reply

mcpackieh2y ago

j / k navigate · click thread line to collapse