Still not sure, does iphone 3 have real GPS ?

[wyx2000]

From what I read , Iphone 3 doesn't have GPS which rely on satellite. That is why company like TomTom sell GPS software for iphone with a special iphone holder with GPS chips in.

But then what is NavUSA? it can be just installed on iphone to use.

I am very confused, does iphone have GPS chips in?

 

[TEG]

With the exception of the Original iPhone (EDGE), the iPhone includes AGPS, which is just like regular GPS, with additional information coming from Cellular and WiFi triangulation. I believe the TomTom adapter is just a holder with additional GPS units for better accuracy.

TEG

 

[Intell]

The iPhone 3G, 3Gs, and 4 all have real GPS. Even though it is aGPS, it is the real thing.

 

[seajay96]

TomTom's car dock uses an antenna and receiver with a higher sensitivity and a clearer view of the sky than the iPhone by itself and can also be used with iPod Touch and even the iPad (with a dock extender).

It also has a built in speaker for better turn by turn announcements.

It works great, but is far from necessary to get your iP3 to do real GPS navigation.

 

[rusty2192]

Since it is Assited GPS, I think it's even better than a traditional GPS receiver. It can find a signal a lot faster due to using the cell signal as a guide. This is especially handy when you move a large distance between turning it off and on. The trade off is less accuracy, but for driving, do you really need to know if you are on the centerline or in the ditch?