[OSM-talk] Good deal on Garmin GPS unit

[Christopher Schmidt]

On Thu, Jul 06, 2006 at 05:49:41PM +0100, Nick Black wrote:
> On 7/6/06, Christopher Schmidt <crschmidt at crschmidt.net> wrote:
> >
> >On Thu, Jul 06, 2006 at 09:59:28AM +0100, Jon Stockill wrote:
> >> Nick Black wrote:
> >>
> >> >RE GSM/Sirf II - I stand corrected!  I've emailed Sirf to see what they
> >> >have to say about it, but it does seem to mean that the chips *can* be
> >> >used with GSM signals.  I don't think that this is A-GPS though.
> >>
> >> ISTR there's a requirement in the USA for newer 3G phones to be able to
> >> provide a position when an emergency call is made - this could be why
> >> the manufacturers are pushing this chipset, since it actually has a
> >> chance of being able to provide a fix while indoors. When used in this
> >> way it's not unreasonable to assume that the GSM cell data will be used
> >> to help with GPS positioning.
> >
> >As far as I know, the requirements for location are only triangulation
> >based, under the E911 legislation, and have been completed for several
> >years.
> 
> 
> E911 legislation originally required that from October 2001, all wireless
> service providers in the USA should be able to locate a user with an
> accuracy of 100m in 67% of cases and 300m for 95% of cases.  The method used
> was not specified - triangulation, dead-reckoning, GNSS etc were all good.
> A-GPS (GPS reception augmented by correction signals broadcast via GSM
> towers) emerged as the front runner.
> 
> Chris: Has this now been implemented in the US?  Six months ago it was going
> to be six months until the E112 legislation came into force and we all had
> A-GPS enabled cell phones in Europe.  Very little sign so far...

I believe that as of about a year ago, all the providers had gotten E911
up and working. Of course, that means nothing to you as a user of the
cell phone -- there's no way to get that information *out* unless you're
an emergency call center, and even those can't get it sometimes. 

Some of them were earlier than other -- I think the E911 legislation
originally said something like mid-2004, which was failed at, and pushed
back by some carriers, until last year, but at this point, I think it's
all up and running.

-- 
Christopher Schmidt
Web Developer