Hi,
On Apr 27, 2010, at 5:38 AM, "Peter Gutmann (alt)" <pgut001.reflec...@gmail.com
> wrote:
GPS tracking units that you can fit to your car to track where your
kids are
taking it (or *cough* other purposes) have been around for awhile
now. It's
interesting to see that recently the sorts of places that'll sell
you card
skimmers and RFID cloners have started selling miniature GPS jammers
that plug
into cigarette-lighter sockets on cars (general-purposes ones using
internal
batteries have been around for awhile). In other words these are
specifically
designed to stop cars from being tracked.
(Some of the more sophisticated trackers will fall back to 3G GSM-
based
tracking via UMTS modems if they lose the GPS signal, it'll be
interested to
see how long it takes before the jammers are updated to deal with 3G
signals
as well, hopefully while leaving 2G intact for phonecalls).
Just wondering, why wouldn't GPS trackers use 2G to determine the
location?
And, also, does it even need a cell service subscription for location
determination, or is it enough to query the cell towers (through some
handshake protocols) to figure out the proximities and coordinates?
Peter.
Thanks,
Pawel.
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