tracking prepaid cell phones

Archie D Bunker

A friend of mine claims that prepaid cell phones can be tracked by the authorities very easily since they send a signal when they are being charged, which enables the cellular provider to triangulate the phone's location if asked to by the authorities, based on the cell sites used to carry the signal when the phone was being charged.

he is not too sure about the details, and I couldn't find any proof for this.
Anyone knows anything about this?

aidan_walsh

All phones send and receive signals that can be triangulated, it wouldn't work too well as a phone without it.

celticbest

aidan_walsh wrote: »

All phones send and receive signals that can be triangulated, it wouldn't work too well as a phone without it.

+1

funkyjebus

sure they can do it. but they need your number first. i hope by charged you dont mean battery charge,if so i think your friend is misinformed or winding you up. for more info see the wire (season 3, afaik is the one about trackin mobiles)

MarkR

The phone would need to be turned on, charging doesn't come into it.

http://www.snopes.com/crime/prevent/cellping.asp has some info on it.

Archie D Bunker

Thanks for the replies, I think I see what got my friend confused - he thinks the phone can be triangulated while charging the battery (when the phone itself is off).
From what I know, while a phone is on, the location can be triangulated even if there is no conversation in progress. I don't know of any way to triangulate the location while the phone is off and charging though.

Solair

If you're phone's off, it's off. It's effectively dead to the world, there's no way that anyone can track it unless they've installed some kind of secret spy devices inside or something!

If your phone's on, including on stand-by, it regularly checks-in with the network to find the strongest signal, and also so that the network knows where to route calls when it needs to call you / send a SMS etc.

If you've ever noticed that a mobile generally rings pretty much immediately when you call it, maybe just slightly less immediately than a landline, this is because the network knows which cell and transmitter to contact instantaneously.

However, if a mobile's been off or out of coverage, you might notice a long silent pause or, on some eircom exchanges a 'bebebebe' routing tone, while the GSM network seeks the phone out.

Basically, the network always knows pretty much where you area and it can be narrowed down with some degree of accuracy using triangulation (as described above).

So, basically you're not entirely anonymous when you use your mobile.

If you're using a phone with GPS, there are protocols in the network for sending your exact location when you call the emergency services .

All calls to 112 or 999 will locate you using the GSM network (As per an EU directive dating back to 2003). AFAIK, some handsets will also transmit your GPS location.

This kind of thing is incredibly useful if you're in trouble and need help.

Also, remember that iPhones, Blackberries, Androids, Nokia smart phones etc may transmit your GPS location to various services. Check the T&Cs of each app you install and make sure you're not sending out your geographical location if you don't want to be.

Apple's new T&Cs seem to allow for wide use of GPS location for advertising etc.