The difference between standard GPS and A-GPS

June 25, 2007 by  

One of the big news in the new Nokia N95 firmware seems to be the added A-GPS (also known as assisted GPS) feature, which basically “is a technology that uses an assistance server to cut down the time needed to determine a location using GPS. It is useful in urban areas, when the user is located in ‘urban canyons’, under heavy tree cover, or even indoors.


Yes it’s an ugly drawing but you get the picture huh?

What does this mean? Well a standard GPS like the one you have in your car, boat or even in your Nokia N95 (with todays firmware) need to synchronize with at least 3 satellites to calculate your position (yes it’s simple math; Pythagoras theorem anyone?). They also need a clear line-of-sight, which basically means no GPS positioning indoors, in tunnels and sometimes not even in your car (if your GPS device isn’t positioned very near a window). Assisted GPS devices are similar to fleet tracking systems because both use cell phone towers for receiving signals.

The Nokia A-GPS system uses an assistance server (Mobile Location Server) via your cellular network. The server either knows or learns the position of your closest cell phone tower and uses this to calculate your exact position. The server has more processor power than your cellphone/GPS and thus makes the calculations faster. The tower positions are also stored in a database for future use making everything work faster and smoother as the system learns new tower positions. This also enables you to use your GPS device indoors.

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15 Responses to “The difference between standard GPS and A-GPS”

  1. Nokia N95 firmware changelog, v12.0.013 at Simply Symbian on July 7th, 2007 01:17

    […] A-GPS support included (quicker at receiving and locking GPS signals) […]

  2. Warranty Void » Blog Archive » Assisted GPS on Nokia N95 on July 9th, 2007 09:54

    […] what some bloggers have speculated, AGPS does not use cellphone network based positioning. Hey, you all […]

  3. GPS Passion on July 12th, 2007 07:59

    Nokia N95 update is a GO!…

    The long awaited firmware update (v12.0.013) to the Nokia N95 phone has arrived, installed and tested by several.
    You can get it HERE at Nokia
    Only looking to the GPS part of this update, the reactions are quite positive overall. I don’t own a N…

  4. Nokia N95 firmware unofficial changelog, v12.0.013 at Simply Symbian on July 19th, 2007 14:51

    […] A-GPS support included (quicker at receiving and locking GPS signals) Enable using Tools > Settings > General > Positioning > Positioning Server & define the access point you want. […]

  5. Nokia N95 official change log v.12.0.013 at Simply Symbian on July 20th, 2007 14:09

    […] up and it seems we’re looking at some major upgrades. Some new features have been added, like the A-GPS I wrote about earlier, but also the new HSDPA (3.5G) indicator on the top left corner, as well as some improvements on […]

  6. scott on October 7th, 2007 13:37

    when you install new crappy software it wont let you reinstall tomtom. be careful. if anyone knows how to bypass this, I would be most grateful, or indeed how to get it back to version 11. thanks

  7. q10min on February 28th, 2008 13:22

    the GPS is complely free …,but how about the A-GPS?

  8. Dario Soltani on February 29th, 2008 14:50

    the A-GPS consumes data traffic, if your carrier charges you for data traffic you’ll have to pay some for the a-gps functionality.

  9. GPS Passion » Nokia N95 update is a GO! on March 27th, 2008 17:17

    […] Little more on this subject: N Series WOM World Nokia Discussion Board Simply Symbian tells how A-GPS works […]

  10. vijay aptec on October 11th, 2008 08:44

    most of the peoples using the GPS in the world, so this option much better in the mobile

  11. anoop on May 7th, 2010 02:16

    i jst want to know whether E90 communicator is having gps and A-gps support.and also how good is the gps in E90 communicator.also tell me clearly the difference between GPS and A-GPS,for both ,the service is paid or free of charge.

  12. Kunal on July 20th, 2010 10:48

    Yes, A-GPS uses the GRPS to download the data and it is chargable.

  13. ravindar on January 18th, 2011 06:38

    does Samsung I5800 Galaxy 3 has AGPS or gps?

  14. ranjith on April 17th, 2011 10:47

    which is faster AGPS or gps………?.

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