Question about iPhone's fake GPS and EDGE

Discussion in 'Jailbreaks and iOS Hacks' started by aspenboy, Aug 31, 2008.

  1. aspenboy macrumors member

    Joined:
    Jul 31, 2008
    #1
    I have a unlocked iPhone that I'm using on AT&T's system without a data plan. When i'm out and about, and use google maps to find my location, it doesn't seem to be able to locate me. Is EDGE required to use the cell towers for the iphone to locate itself? I was thinking that since I am using AT&T and my phone has 5 bars in many locations, it could "see" the towers but use them to find the location, but it doesn't. I understand it shouldn't download the google maps, since that requires a data plan, but sometimes i've preloaded maps and it doesn't find the location on the loaded map.

    Based upon my experience, I figure it won't work, but I thought I'd ask anyway.

    thanks,
     
  2. Chundles macrumors G4

    Chundles

    Joined:
    Jul 4, 2005
    #2
    If you have an iPhone 3G then it's not fake GPS, it's real GPS. It has a GPS antenna in the phone.

    A data connection is required to download the map data to the phone. Pre-cached maps can be used.
     
  3. aspenboy thread starter macrumors member

    Joined:
    Jul 31, 2008
    #3
    sorry I didn't make myself clear in the original post. I have an original iPhone (not 3G) and don't have an EDGE data plan. Just cellular access on the AT&T network and WIFI. When I'm on Google maps, I don't seem to be able to get a location for myself, even if I've precached a map of the area i'm in.
     
  4. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #4
    In his/her defense, if the iPhone is unlocked, it's probably not 3G. ;)

    I'm confused though about what you're doing... are you out using a WiFi connection? If you don't have EDGE availability and you're not on a WiFi access point, Google Maps should not be doing much for you. I haven't really tried tests like having it locate me when I'm on a map I've already downloaded and yet I've walked off the EDGE grid, but... yeah, I don't think you'll get anywhere this way.

    It should be able to locate you off of WiFi, but again, unless you're also legitimately connected to that wifi so you can use it as a data source, how are you going to use Google Maps?
     
  5. equlizer macrumors regular

    Joined:
    Aug 12, 2008
    #5
    There is no GPS antennae inside the phone:rolleyes: The Iphone 3g has A-GPS (assisted) which goes off cell towers just like everything else on your phone.

    I bet you $1000000 that your gps will not work if you put it in airplane mode:D
     
  6. Ntombi macrumors 68030

    Ntombi

    Joined:
    Jul 1, 2008
    Location:
    Bostonian exiled in SoCal
    #6
    You're confusing two different things.

    No, GPS won't work in airplane mode, but that's because airplane mode turns off all the radios and receivers in the phone.

    But it IS real GPS. A-GPS is assisted by first using the cell towers to tell the GPS where to look (I'm not using the official terminology, but that's what it does), but GPS antenna does get information from satellites. It is "REAL."

    In case you want to know what you're talking about, go here.
     
  7. Asha'man macrumors newbie

    Asha'man

    Joined:
    Jul 15, 2008
    Location:
    Atlanta, GA
    #7
    If you have a 1st generation iPhone, then the semi-gps-like feature built into google maps is entirely based on cellphone tower triangulation. In order for that to work, the phone needs to get a little bit of data from the tower (the tower knows where it's located, your phone doesn't). Without a data plan, you may not have a path to get that data. I can't say for sure, but it certainly seems probable that you won't get location services with your setup.

    As for the 3G A-GPS phone, it does have a genuine GPS receiver (which is more than just an antenna). The A-GPS logic uses data from the cell tower to help speed up getting a lock, but it's perfectly capable of locating you when no towers are around. (Getting map data, on the other hand, require some form of net access.)
     
  8. 127079 Guest

    Joined:
    Sep 20, 2007
    #8
    Hi,

    I have this same issue as well... Was with a Mac Genius yesterday and they say it is a firmware issue and should be fixed in the next firmware update..|They went through a bunch of questions on where google maps (not locate me) works postcodes and when was last time it worked and sent it to the engineers..The genius also offered me a replacement if I wished to prove it is a firmware issue.

    ren

    ps:we even went outside and tried to locate our selves but to no luck ( he has a 1st gen iphone non 3G)
     
  9. JPIndustrie macrumors 6502a

    JPIndustrie

    Joined:
    Mar 12, 2008
    Location:
    Queens, NY
    #9
    Hahaha. I love everyone rushed to defend their jesusphone 3G, when he wasn't even talking about it.

    From what I've read - the iPhone does not use triangulation - a user from another forum named 'XFF' has a better explanation:

    So, since it seems to be relying on GSM signals, not necessarily GPRS or EDGE, theoretically you may not need a data plan to use Locate Me. HOWEVER, it would be useless without a data plan anyway as while the cellular signal may be sufficient to give your phone location data, without a data plan, google maps cannot load the maps and track your location.
     
  10. aspenboy thread starter macrumors member

    Joined:
    Jul 31, 2008
    #10
    Thanks for those who answered.

    I think I had it already figured out, but thought it might be useful to get confirmation. For example, last weekend I went for a bikeride across san francisco. I precached maps of SF by scrolling around the city when I was at home (in the East Bay). So I could scroll around the map even when I wasn't connected to the internet (WIFI or EDGE). Occasionally, when I had WIFI access, google maps was able to locate me on the map. Since I don't have a data plan, it didn't work locating me when there was no WIFI around. The main question was whether or not having cellular access should be sufficient to locate me and the last response gave me the answer, that data not just cell phone access is required to send the tower ID to actually locate the phone on the map.

    It'd be nice if I could get location data, without a data plan but I can get a contract-free data plan with my Pay as you Go plan from the TUAW post:
    http://www.tuaw.com/2008/05/13/tuaw-hands-on-trying-out-the-20-month-contract-free-unlimited/
     

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