Does the iPhone’s GPS work solely on satellite signal?

Posted: 5th August 2012 by Jacky Yong in Computers
Tags: , , ,

This is a question that has been bugging me for a long time, since my Nokia 5800 days. On my Nokia, the GPS function works very well, but that was when it was used as a normal phone. But when I changed to an iPhone, I wanted to keep the 5800 as a GPS device, since I thought that it can work independently from my service provider. The GPS took ages to lock, if it even locks at all. I begin to suspect that normal GSM signal also help in determining your location.

Here using my iPhone, I do a simple test. I turn off wifi and turn on airplane mode (no GSM signal from Maxis). Then I tried to locate myself using my Garmin. Here’s a screenshot:

Searching .....

Searching …..

It took me ages to get a location lock. Note the airplane icon on the top left, indicating airplane mode. Then I turned on GPS, and guess what?

Ready to Navigate

Ready to Navigate!

It’s confirmed, turning GPS on alone is not enough for GPS to work. It also depends on either GSM signal or wifi. I tried turning on wifi (I am using a YES modem), and it also can lock my location too!

Now I know …..

EDIT : Reader Darren reported that this is the same for the iPad 3 as well. In airplane mode, GPS does not function. When airplane mode is off, GPS works, even without a SIM card. Thanks Darren for the info!

  1. Snoopy says:

    Most phone GPS system is using AGPS…

  2. Jacky Yong says:

    Yeah, no wonder …… 😛

  3. Darren says:

    In airplane mode, GPS is not functioning.
    But normal mode, GPS is functioning even without a SIM card.
    Tested on iPad 3 without any SIM card to act as a normal GPS running Garmin.

  4. Jacky Yong says:

    Hey thanks for the heads-up! Does this mean that it only works on GPS signal? I assume that you are not in any wifi range right? Let me update this info into my post 😉

  5. Darren says:

    Yup, I can confirm that whenever airplane mode is enabled, no GPS at ALL!
    Maybe this is because of the GPS chip/function is built inside GSM chip…

    I use my old iPhone 3G as iPod Touch to read texts (without any SIM card inside). I spent days to find out why my GPS is not working (I enabled airplane mode to kill phone background service), when I accidentally disabled airplane mode, the GPS function is working!

    All the way while I’m driving I’m referring to the GPS, of course no WiFi, I even turned it OFF.