iPhone 4 iOS 4.1 beta, dB to bar mapping exposed

by Justin Horn on Jul 15th, 2010 @ 1:49 pm


While the software update obviously does not and cannot address the design of the antenna itself – or make the drop from holding the phone any less – it does change the way the issue is perceived among users. The result is that most iPhone users will see fewer bars disappear when they hold the iPhone 4 in a bare hand. The side effect is that the iPhone now displays fewer bars in most places, and users that haven’t been reporting signal in dBm will time see the – perhaps a bit shocking – reality of locations previously denoted as having excellent signal.

Interestingly enough, Apple has indeed changed the heights of bars 1, 2, and 3. They’re taller, and the result is that the relative heights are no longer linear, but rather a tad exponential looking. It’s a mind trick that Apple no doubt hopes will make the signal look better. If the bars are taller, they must denote stronger signal, right?

Even with Apple’s “magicalness”, they still can’t fix hardware issues with software alone.

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View 3 Comments
Antenna Issue, iOS 4.1, iPhone 4


  1. ok then
    July 15th, 2010 3:53 pm

    If you read the Apple’s press release correctly they are using AT&T’s formula for bar indication. I think it’s kind of unfair to say that Apple is trying to make the signal look better than it is. They’ve simple adopted AT&T’s code to reflect AT&T’s network. Why they hadn’t done this before is beyond me but irrelevant to the accusation you’ve made.

  2. 2.
  3. Justin Horn
    July 15th, 2010 4:05 pm

    What they are referring to hear is not the number of bars or the signal, but making the lower bars taller graphically. This way it tells your brain, taller bars equal better signal.

    Has nothing to do with AT&T.

  4. 3.
  5. Bryan
    July 19th, 2010 1:29 am

    Or to make these smaller bars more visible. Whatever way you want to spin it.

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