What's "Assisted GPS" used for???

Discussion in 'iPad' started by iBighouse, Mar 16, 2012.

  1. iBighouse macrumors 6502a

    iBighouse

    Joined:
    Mar 11, 2012
    #1
    I see from the tech specs on the apple site that the 4GLTE model of the new iPad has "Assisted GPS". What does that really do?

    Are all the location services that I currently have on my iPhone 4S, like knowing where I am on a Google Map, and for things like "Find My iPad" still fully functional if my iPad has a Wifi connection???

    I guess what I'm asking is does the iPad still use some kind of global positioning locator if one doesn't buy the 4G model, or is it simply showing you your location based on the wifi hotspot location? Is one more accurate than the other for your iPad's actual location???

    I doubt very much I'll be needing 4G service and think the wifi model might work just fine for me- but don't want to limit the ability to use features.
     
  2. VaughnA macrumors newbie

    Joined:
    Nov 3, 2006
    #2
    Assisted GPS uses information from the Cellular system to help get a faster location from the GPS in poor coverage areas. A gps locks faster when it knows the approximate area that it is located in. The cellular system can tell the phone its approximate location and the GPS locks faster and with more accuracy.


     
  3. seajay96 macrumors 6502

    Joined:
    Jun 26, 2010
    #3
    Not really, the GPS receiver in the iPhone and iPad are physically located on the cellular service circuit board. So, if your iPad is WiFi only, you will not receive a GPS signal. Assisted GPS only means it boosts the signal acquisition speed and accuracy using cell towers. With WiFi only, you'll get WiFi triangulation but it's not nearly as accurate.

    BTW, if location services are important to you, you can by the 4G model but you don't need to subscribe to data services to make the A-GPS work.
     
  4. johndoe588 macrumors regular

    Joined:
    Apr 27, 2007
    Location:
    Upstate New York
    #4
    The "assisted GPS" of the 4g models means the iPad uses cellular or wifi information to get an idea of position, letting the GPS receiver function locate you more quickly. The 4g models, like the 3g ones before, have actual GPS receivers. The wifi only versions do not, but still do a pretty good job of locating you using cell towers or wifi.
     
  5. iBighouse thread starter macrumors 6502a

    iBighouse

    Joined:
    Mar 11, 2012
    #5
    Wow, that was all great info and fast. Thanks everyone. What kind of accuracy difference are we talking about between a wifi triangulated location and an actual A-GPS determined location? 10 feet? 100 feet? 200 feet?

    And, you don't need to pay for Data Usage to use the GPS receiver on the 4G model??? The GPS receiver works on Wifi????
     
  6. Gav2k macrumors G3

    Gav2k

    Joined:
    Jul 24, 2009
    #6
    Wirelessly posted (iPhone 4s: Mozilla/5.0 (iPhone; CPU iPhone OS 5_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B179 Safari/7534.48.3)

    No the gps chip receives its information from satellites not wifi or cell towers. So you don't have to have data available.
     
  7. deeddawg macrumors 604

    Joined:
    Jun 14, 2010
    Location:
    US
    #7
    With GPS you can use turn by turn navigation software like NavFree GPS that loads the maps locally.

    I haven't really used the wifi only much so in the little I've played with it the Maps app located me to within a couple houses. GPS showed whether I was at the front window or the back window.

    No, you do not need to be subscribed to data. Works on wifi or off of wifi (if everything is stored locally as with a navigation app). GPS chip listens to the signals from the orbiting GPS satellites.
     
  8. poloponies macrumors 68030

    Joined:
    May 3, 2010
    #8
    The GPS works from a network of dedicated satellites (it seeks input from three nearby satellites which transmit their location and a synchronized (between the satellites) time signal. Because the length of time for the signal from each satellite differs, the receiver calculates the triangulated location that you're in). You can access the satellite signals independently of cellular data but you still need map data to be loaded onto the device, otherwise your location will not be readily identifiable to you.
     

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