Cell location Question

Discussion in 'iPhone' started by AndroidfoLife, Apr 24, 2011.

  1. AndroidfoLife macrumors regular

    Mar 27, 2011
    So I was wondering when I dial 911 on a cellphone does it access my GPS to route me to the nearest dispatch or does it go by my area code.
  2. The Californian macrumors 68040

    The Californian

    Jan 17, 2009
    Surfers Paradise
    Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_2 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8H7 Safari/6533.18.5)

    It uses your the cell tower you're connected to.
  3. RafaelT macrumors 65816


    Jun 9, 2010
    Lakeland, FL
    Pretty sure it actually is based off of the cell tower you are connected to at the time.

    The 911 system, while it has made some great progress in the last 10 years is not that advanced.
  4. Daveoc64 macrumors 601

    Jan 16, 2008
    Bristol, UK

    Using GPS would be very complicated (and in some cases impossible), as there would need to be some way for the 911 agent (or other emergency service around the world) to communicate with your phone, tell it to find its location using GPS and then report that back to the agent on the phone.
  5. Stealthipad macrumors 68040


    Apr 30, 2010
    Might be both but the tower you are currently connected to is recorded and maintained by the carrier for months for law enforcement purposes. GPS would only enhance your fix.:)
  6. kdarling macrumors P6


    Jun 9, 2007
    First university coding class = 47 years ago
    As it can take up to six minutes to get a location fix, it goes by the tower first.

    However, in many parts of the USA you still might get connected to the State Highway Patrol instead of a local E911 center. They will ask where you are and direct your call appropriately.

    There have also been cases where the tower was in one jurisdiction, but the emergency was in another, and that caused deaths because of delays figuring out location and the correct response agency.

    So Mobile E911 RULE #1: always state your location first. And your cell number. They might not have either and if your call gets dropped, they might not know how to call you back.

    In addition:

    • A phone doesn't have to be currently activated to make E911 calls.
    • The phone is allowed to use any compatible carrier, whether you have an account with them or not.

    Interestingly, with CDMA carriers like Verizon, that's what happens automatically: the network asks the phone to use its A-GPS and give back either raw data or its position. This is done over an internal network control channel, and does not use the internet like most A-GPS implementations.

    GSM carriers locate the phone using towers alone, which is not as accurate.

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