iPhone Field Mode (what AT&T uses for signal strength)

Discussion in 'iPhone Tips, Help and Troubleshooting' started by gregbenj, Jul 31, 2008.

  1. gregbenj macrumors member

    gregbenj

    Joined:
    Jun 28, 2006
    #1
    Putting iPhone in Field Test Mode allows user to assess signal strength numerically. Field Test Mode also allows user to assess cell tower information, etc through an iPhone interface. Basically, this is the tool that AT&T uses to evaluate area coverage. How do I know? After writing Steve Jobs about my poor coverage, AT&T sent a team to my house and showed me this diagnostic tool -- though they couldn't improve my coverage.

    When Field Test Mode is activated, the signal bars are replaced by a dBi reading. Around a tower, the reading should be lower (i.e., less negative). It depends on the specs of the tower, but for me, they told me that I should get a -50 reading when near a tower. Gradually the signal will get more negative when you are farther from the tower (unless another tower is picked up). For my situation, AT&T told me that when the reading was around 100, signal strength is poor. (The 100 is not displayed as negative because there is only enough room for three characters.)

    To access Field Test Mode, go to phone icon, then to keypad and dial *3001#12345#*call. Not sure if this number will appear on the bill, but I doubt it. To Exit, just hit the home button.

    What are everyone's readings at home? Can anyone else figure out the information give from the other tools that are included?
     

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  2. Interstella5555 macrumors 603

    Interstella5555

    Joined:
    Jun 30, 2008
    #2
    I'm in...I'm not sure all the numbers you're looking for (those sub-menus are for telecom experts apparently) but I'm getting -75/-77

    Also interesting to note that this doesn't come up as an outgoing call....
     
  3. gregbenj thread starter macrumors member

    gregbenj

    Joined:
    Jun 28, 2006
    #3
    ya i'm -92 to -107 at my house. I've been dropping calls like crazy. This might just be the numerical data that makes me switch back to verizon :(
     
  4. benflick macrumors 68020

    benflick

    Joined:
    Jul 11, 2008
    Location:
    Cincinnati, Ohio
    #4
    its not just for att, i tried on cincinnati bell, i got -89 and it didnt bill me
     
  5. benflick macrumors 68020

    benflick

    Joined:
    Jul 11, 2008
    Location:
    Cincinnati, Ohio
    #5
    its not just for att, i tried on cincinnati bell, i got -89 and it didnt bill me
    :)
     
  6. bmms8 macrumors 68020

    Joined:
    Dec 19, 2007
  7. ImARockStar macrumors newbie

    Joined:
    Jul 29, 2008
    #7
    -81 at my work but im at full bars so what does that mean. Also on edge as of now due to no 3g.
     
  8. gadgetdad macrumors 6502a

    gadgetdad

    Joined:
    Sep 10, 2007
    Location:
    On my iPhone
    #8
    -77 at work for me.

    Any other cool numbers to dial up?
     
  9. Kris B.. macrumors member

    Joined:
    Jun 10, 2008
    #9
    Ya, I have full bars as well and am getting like a high 80- 90 reading, wtf?
    Also I've noticed that when locked and I press the sleep wake button it appears i have full bars but once unlocked it drops randomly to 3? Is that normal due to the network or something.
    PS this doesn't just happen at my house it happens all the time
     
  10. macduke Suspended

    macduke

    Joined:
    Jun 27, 2007
    Location:
    Central U.S.
    #10
    Did this trick last summer.

    -71 at home here.
     
  11. in2muzikk macrumors newbie

    Joined:
    Oct 17, 2008
    #11
    -87 to 113 alternating with NO SERVICE at work (Hollywood, CA 90038, which shows up as "strongest 3G signal" when looking at AT&T's coverage map). Phone alternates between Edge and 3G, but is mostly on Edge.

    -89 to 113 alternating with NO SERVICE at home (West Hollywood, CA 90069, which is just inside the border of "strongest 3G signal" and adjacent to "strongest Edge signal" when looking at AT&T's coverage map). Phone is most always on Edge.

    Driving back and forth along Fountain Blvd. between La Cienega and Highland Ave, -90 to 101 with occasional reductions to -71 or so near major intersections (had this reading at Fairfax). Phone shows Edge most of the time, but occasionally switches to 3G.

    I'm getting dropped calls in all of these areas. I cannot receive a call at work, when I say "Hello" several times there's nothing on the other end. When I call back, the call always connects however. Using firmware version 2.1 and AT&T has also replaced the SIM card, but no change in results. :confused:
     

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