At 12 Jun 2008 23:59:08 +0000 Larry wrote:
> Right, thanks. If GPS could do what Sellphone vendors want....GARMIN,
> not
> them, would have already been doing it.....and they're not because it's
> physically IMPOSSIBLE.
My Nemerix-based iBlue BT GPS does a pretty good job indoors- the first GPS
I ever owned that worked inside my house.
But even forgetting that, there are more ways than just GPS to locate a
cellphone- you just seem to get worked up over semantics. Take tower
triangulation, for example-think of it like a lower-quality backup for GPS,
much like GPRS is a lower-quality backup for 3G. This allows cellphones to
use tower location where/when GPS doesn't
work (indoors, prior to first fix after cold starts, etc.) Sure, it isn't
true "GPS", but if it quacks like a duck...
And Garmin WOULDN'T be doing THAT unless they build a nationwide two-way
radio network to receive signals from their GPS units and estimate their
position based on triangulation and timing like the cell companies can.
Why shouldn't cell companies leverage their positioning info as an
augmentation of (or substitute for) "real" GPS, particularly when the Feds
make them do it for E911 anyway?
> Now, I CAN see the sleazy sellphone bastards bullshitting the customers
> with some GPS app that gives them the lat/long of the towers, which does
> have a GPS receiver in them because it is where the TIME set on your
> sellphone display comes from. Look at a cell near you closely and you'll
> see a little white dome antenna down on the building or near the base of
> the tower feeding a small coax into the building. That's a GPS antenna,
> just like the ones on someone's yacht.
>
That's only part of it- the cell company knows via timing exactly how far
from a tower a phone is. Armed with that information, fairly accurate
location of phones with NO on-board GPS (like iPhone the First) is possible
with cell carrier intervention (which even makes the claims of "GPS" being
"added" to v1 iPhones with the 2.0 upgrade possible, if you'll stretch the
definition of "GPS" to include ANY location method.)
WiFi makes it even easier- before the iPhone/iPod Touch/Google WiFi stuff,
a little clown outfit called Navizon (
www.navizon.com) has been offering an
app for WinMobile (and jailbroken iPhones!) for over a year that uses a
community-created WiFi/cell location database contributed to by GPS-enabled
phone users (that frankly worked better in Manhattan for me last week than
my BT GPS did!)
Technical Specs of iPhone 3G posted
Linear Mode
