posted on Jul, 27 2014 @ 03:46 AM
I thought I'd try and give a bit more of a technical answer seeming people are assuming triangulation is based on 'masts'. I don't mean this in a
bad way, but it sounds very movie-ish, along with questioning if your SIM can be tracked when not in a phone.
The SIM one is easy, no it can't. The current versions of SIMs being used don't have a power source, could that change? Possibly but how many people
are really carrying a SIM just to insert in a phone for a short period of time?
It's also worth nothing what a SIM's purpose is - Subscriber Identity Module - that's its name if you want to read up on Wikipedia... Knowing its
name probably makes more sense, it provides access to the network and its services. For those in the UK that have a BSkyB subscription, your viewing
card is an old version of a SIM card.
Triangulation - this is technically possible but you're not connecting to masts. A mast is just a structure that may have a Base Transceiver Station
(BTS) on it, the reason I pick up on this is just so you know a a BTS can be anywhere, a building for an example.
So a very brief explanation, when you power your phone on, its job is to connect to a BTS, register on the network and provide the services you're
entitled to. One of these is finding you the best phone signal. As Americans are probably more likely to know, these are part of a cellular network
(they call them cell phones). A BTS runs on a specific frequency which they have purchased. (in the UK back when Gordon Brown was chancellor of the
exchequer, he decided on 5 companies could operate 3G networks - other mobile offerings would use these networks).
However, a BTS can only accept a finite amount of connections, so you need another cell on a different frequency, which means cells are shrinking to
increase their capacity.
Why is this important? Well, modern technologies allow you to utilise more than one cell (Dual Cell - HSDPA). So you are establishing connections with
multiple cells. Each cell or, BTS has a BSC - Base Station Computer. This isn't always at the BTS and BTS's can share BSCs. The important, or
interesting part is, there is a VLR - Visitor Location Register, this basically holds the information about what BST you're connected to.
It can also hold dBi information from your phone, this is essentially how your phone decides where the best signal is coming from. From this you could
calculate an estimated distance, use enough rating for enough BTS and you could get a decent set of coordinates.
The above was geared towards the original question of a more simple phone, granted it's not going to be using DC-HSDPA, however that was more to
demonstrate multiple cells.
More modern phones, your iPhones etc start to pull in a lot more. Google came under fire when it was discovered their street view vans were also
capturing data for wireless networks. So if your house has a WAP - Wireless Access Point, the data you're sending to and from that with your various
devices can be captured.
Now this isn't particularly difficult, most wireless chip-sets have the ability to go into 'monitor mode' which allows you to just sit and watch
This is what they were doing, exactly why they were doing that and saving the data, who knows we can only speculate. Though the reason they were
wanting WiFi information is to provide a poor-man's GPS. So when you're on the street it can calculate your position by local access points.
You also have GPS as mentioned and various other sensors which can simply transfer this information.
To give you an idea of how trivial this is, years ago when I was a student I used an Android phone and tablet to create a tracking device. It was
course work and I designed it around a monitor for the elderly. Anyone with some fairly basic programming abilities could do this, I was able to take
accelerometer information and decide if that person was moving, I could tell if they had their phone on charge etc etc, this was also syncing with a
database whenever it could connect and all actions were timestamped.
The user would have no idea this was happening.
Oh and unregistered phones are almost certainly flagged, and it's not too difficult to create a pattern of locations. So if you are planning on doing
something illegal and relying on your phone, never turn it on in your house or even home town, never buy a top up card within your town etc etc. These
are all things that can be tracked and again, trivial for a computer to spot a pattern and work out what area you live in.