maemo.org - Talk - View Single Post - Why aGPS in N810, iPhone ?

darius2	2008-09-03 , 13:29
Banned \| Posts: 57 \| Thanked: 2 times \| Joined on Jul 2008	#5

Originally Posted by ragnar

You're mixing up a couple of things, hopefully accidentally. AGPS is not a chipset like Sirf, it's a way to assist the selected chipset with cell signals. Many SIRF based solutions also use AGPS additionally to improve performance. iPhone is using the Broadcom chip and AGPS.

http://seekingalpha.com/article/4774...ps-partnership

Or:
http://artoftheiphone.com/2008/06/10...-assisted-gps/
"The main advantage of Assisted GPS (AGPS) for the iPhone is that it will allow the iPhone’s GPS to operate in weaker signal conditions and determine positioning quicker than most standalone GPS receivers. AGPS also helps save battery power by handing off some computational duties to an assistance server and by allowing iPhone users to turn GPS off and on with less inconvenience."

I don't buy such explanation.
There is a number of fast fix, strong signal gps enabled PDA, cell phones, already on a market.
AGPS means exactly what it means.
No intelligent Sirf III or better fast fix, strong signal chip installed
so assistance required.

To get a fix on my Motorola A1000 AGPS in non-assisted mode
it took sometimes one hour or more.
Assistance server like Skyhook for iPhone is database of geocoded cellular base stations, wifi spots, basing computions on a triangulation algorithm (signal level received).

As I can use my $100 full gps car navigation on the go to get fix in
15-20 sec I still see no reason to implement old solution like agps
into new product.

Just enter into Google search : cell phone + Sirf III
to see, AGPS has gone, as an alternative solution in times, Sirf III chip was not available.

Darius