RAC locates you via your mobile?

On those new RAC TV adverts it says they can locate your breakdown using your mobile phone. How do they do this? Is this only if your on certain networks? How come just the RAC do this and not the AA?

Reply to
Tony S
Loading thread data ...

Any mobile can be traced by anyone, provided the owner has agreed to it. it is just a selling point for the rac

mrcheerful

Reply to
mrcheerful

I think it is done by using three mobile phone masts. They test the signal strength from each mast, and then they can predict roughly where you are between them. I think it's accurate to within a few meters.

Reply to
petermcmillan_uk

probably not even that. How do they know whats blocking the signal? Could be a row of buildings on one side, and empty fields on the other.

Reply to
barry

... or even if they haven't agreed to it, for some agencies. A certain Serb was lucky to avoid being blown up a while back when a missile was dispatched to where it was thought he was (on the 'phone). As far as I know, the location is done by triangulation. Location is likely to be more useful in rural locations than urban, seemingly.

Reply to
Chris Bacon

AFAIK they use signal timings not strength to triangulate, so should be effected too badly by the environment.

CPS who were one of the original innovators of the idea suggest their basic product has an accuracy of 300m-3km (depending on number of cells within range etc.). Newest product improved to around 250m, although I'd expect better in the heart of a city with plenty of masts within hailing distance:

formatting link
Just about useful if you've broken down on a motorway and can't remember the last junction you've passed. But not as accurate as walking to the nearest emergency phone box, and quoting the number on the post.

IMHO completely useless if you are on a B road in the middle of the countryside, but makes for nice marketing gumph.

I often see triangulation of mobiles being quoted as miraculously accurate even by the mainstream press. Is this a Hollywood invention?

Reply to
Rufus Addis

The message from "Joe" contains these words:

Yeah, but by the time they're that close they can hear the pinking.

Reply to
Guy King

Multipath distortion, innit? But unless the location arithmetic has improved a lot from the accuracy achievable when I last looked, that would have to have been quite a large missile.

Reply to
Sam Nelson

In the latest Orange cinema ad (Daryl Hannah's) our hero claims, through clenched teeth, that someone could be located `if they had GPRS on their phone'. Does that make sense? Does it help? If so, how?

Reply to
Sam Nelson

The message from snipped-for-privacy@ssrl.org.uk (Sam Nelson) contains these words:

There is impending legislation in the US to make all new mobiles be intentionally radiolocatable. It may even be here now. IIRC it includes a stand-by mode instead of turning off so that it can be woken up by a suitable signal. Obviously this takes a lot less battery power than the phone itself transimitting its position all the time to cellmasts - it just waits till interrogated then talks at full power for as long as it can.

Reply to
Guy King

It can be very accurate if the phone is asked by the network to report sinal strengths back to the network.

Clearly the network knows approximately where the phone is by which cell/sub-cell/sector the phone is in, and what other cells can 'see' it, but if the network then asks the phone which cells it can 'see' including other-network cells, then an accuracy of better than 50m is achievable.

Provided the precise location of the cells is known...

Think of AGPS as provided by Three.

Reply to
Paul Cummins

petermcmillan snipped-for-privacy@yahoo.com reckoned that...

It's nowt to do with signal strength, it's a parameter called "timing advance" which is measured. Accuracy is reasonable but improves in line with the number of transmitters covering the point being calculated. The technique is called "cell site analysis" and was most recently/infamously used to help convict Ian Huntley.

formatting link

Reply to
Jon

In message , Jon writes

However in this instance the police were very lucky. I believe the evidence was limited to which cell Jessica's phone signed off to rather than a measurement of timing advance etc. By some fluke Jessica's phone used the Burwell transmitter rather than Soham's, and combining that information with the known route the girls took, they were able to identify accurately which areas had a "blind spot" to the Soham transmitter. Details and a better explanation here:

formatting link
Had they not known roughly where the girls were, or had the phone signed off to Soham instead of Burwell the mobile cell site analysis would have been limited to pretty much "within 2km of Soham".

Reply to
Rufus Addis

I remember software for the Nokia 6600 which would tell you where you were in the world, and change profile depending on whether you were. Useful :)

Reply to
Marc

Do you mean metres..? I don't have 100 meters on my car dash ;-)

Ivor

Reply to
Ivor Jones

Did you mean GPS..? Many American mobiles now have GPS (satellite nav) circuitry built in, apparently it's a requirement for 911 (emergency) calls or something.

Ivor

Reply to
Ivor Jones

No, the advert is referring to the 'Find where you are' service on Orange World. Just an advert for an Orange service I'm afraid Ivor!

Tariq

Reply to
xycom1

Yup, radio triangulation - hardly a new concept - are they only just starting to utilise this to some decent sort of advantage?

Reply to
AstraVanMan

It's done off the timing, not the signal strength

On a good day if you're lucky

Their positions very well known

Reply to
Duncan Wood

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.