5 ms·

Even with the 3G model the GPS chip isn't a "true" GPS chip. It's Assisted-GPS, and probably pretty unreliable without a 3G connection, just like the iPhone.

• chaosmachine 17y ago
  Assisted GPS is true GPS plus faster initial position finding (that's the "assisted" part). Anyone who's owned a hand-held GPS can tell you it takes a few minutes to find your initial location, especially if you've moved location since the last time you turned it on. An AGPS system uses hints from cell towers to get a rough idea of where you are. This significantly lowers the time required to get a lock. http://en.wikipedia.org/wiki/Assisted_GPS http://en.wikipedia.org/wiki/Assisted_GPS So, yes, it will function without a 3G signal. The problem, however, is that when you're out of 3G range, you won't be able to download Google Maps data. So, if you need maps when you're out in the middle of nowhere, you'll probably want to buy the TomTom app, or one of the other "real" GPS apps.
  • gaius 17y ago
    Anyone who's owned a hand-held GPS can tell you it takes a few minutes to find your initial location Yes, this is because a current (within the last few hours) version of the almanac (current status of the GPS constellation, which satellites are active etc) and ephemeris (more-or-less where everything is expected to be) needs to be downloaded. It's slow from satellites but quick via 3G.
  • wooster 17y ago
    I sell offline mapping iPhone apps. The GPS chip in the iPhone sometimes works (in open fields, clear view of the sky) without assistance, but often does not where standalone units would. This may be a software problem. Core Location has a tendency to give up pretty easily, whereas a standalone unit would keep trying as long as you wanted it to.
• bmalicoat 17y ago
  Didn't this little thing get killed off during the 3G announcement? A-GPS > GPS. Same GPS chip but uses other data to quickly get a general location so you aren't waiting for satellites without any knowledge of your location.