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Late last month, Anandtech detailed the signal strength drop-off experienced by iPhone 4 users when bridging the antenna gap at the lower left corner of the device, mapping how the "bars" of signal strength shown on the device correspond to actual signal levels and how holding the phone in various positions affected that signal under iOS 4.0.


160322-signal_strength_rescaling.jpg


Anandtech has now followed up with a test on Apple's iOS 4.1 beta released yesterday that includes changes to how the visual "bar" indicators correspond to actual signal strength. Anandtech has also confirmed that the changes in today's iOS 4.0.1 update have the same effect.
The results are conclusive - Apple has dramatically changed the signal strength to signal bar mapping in iOS 4.0.1 and the iOS 4.1 beta, making the dynamic range not only much broader, but the range values for each bar much wider. The range of signals that correspond to bars three and four are the same width, and bar two is only slightly less.

The cutoff value for two bars to one bar remains the same, but every other value has increased. The result is that the worst case drop of 24 dBm no longer makes all the signal bars disappear, but rather two.
Notably, Apple has adjusted the bar scale such that the lowest bar remains visible at a signal level down to -121 dBm, significantly lower than the -113 dBm limit in iOS 4.0. Anandtech's report claims that voice and data transmission on the iPhone 4 remained intact all the way down to -121 dBm, bolstering Apple's claims of increased overall sensitivity and reception with the iPhone 4's design.

The report claims that Apple's changes are doing away with a cover-up of AT&T's poor network coverage in many areas and will likely result in some confusion as customers see fewer number of bars than they are used to. The fact that Apple has also increased the heights of the lower bars alongside the change to the mapping of actual signal to bar display appears to be a ploy to somehow makes things appear better than they are, with the subtle, but baseless, suggestion that taller bars imply better signal.
The new signal strength visualization in iOS 4.0.1 is simply going to be more honest with iPhone users. Whether that's going to result in customers confused about why their phone performs "worse" after the update or simply get really mad at AT&T remains to be seen.
Regardless, many observers are expecting to hear more about Apple's response to the signal issue at the company's press conference scheduled for tomorrow. While the company's changes to the signal strength mapping and display may offer a more accurate representation of cellular coverage in a given location, it does not yet address the actual drop in signal seen with the iPhone 4's antenna design.

Article Link: Apple's Signal Strength Display Changes in iOS 4.0.1 and 4.1 Detailed
 

ijen0311

macrumors 65816
Jul 4, 2009
1,108
33
I liked my old, lying bars better. They looked complete. There, I said it. :eek:
 

zxcvb

macrumors regular
Sep 14, 2008
107
0
if bar display is the only change of new IOS , it's not worth time to do the update.
 

VenusianSky

macrumors 65816
Aug 28, 2008
1,290
47
So they increased the dB range for one bar. So before, if I got -119 dB, for example, it just went to No Signal. But now, I will have signal at -119dB. Is that correct?
 

JPark

macrumors 6502a
Jun 5, 2006
662
158
They're gonna get a ton of complaints from people who's reception "just got worse all the sudden." Just like those folks who complain that their plants are dying because of the 1 hour less sunlight when we switch to Daylight Savings Time.
 

reckless2k2

macrumors 6502a
Jul 10, 2008
525
0
Hhhhmmm....I don't think AT&T is going to be too happy about this. It totally seems like they are loosing the deal.
 

alectheking

macrumors 6502a
Mar 9, 2010
584
28
I'm not upgrading till tomorrow and most likely won't even pull the trigger till 4.1. I'd rather have my jailbreak
 

appleguy123

macrumors 604
Apr 1, 2009
6,863
2,541
15 minutes in the future
They're gonna get a ton of complaints from people who's reception "just got worse all the sudden." Just like those folks who complain that their plants are dying because of the 1 hour less sunlight when we switch to Daylight Savings Time.

Do they really complain about that during dst? I hope for humanity that people are not that stupid.
 

Piggie

macrumors G3
Feb 23, 2010
9,117
4,016
Forgive my ignorance :)

But can't we just have a number rather than trying to represent things in bars?


If 100 was the strongest signal the phone could ever receive and zero was when the call was dropped due to not enough signal to maintain the connection.
 

ijen0311

macrumors 65816
Jul 4, 2009
1,108
33
I wonder if the "more bars in more places" commercials will have some slope to them now? :confused:

:D
 

nwcs

macrumors 68030
Sep 21, 2009
2,722
5,262
Tennessee
I have no problem with a slightly taller bar for the lower signals. Personally, I think they should all be the same height and you merely count rather than the cutesy idea of graduated height.
 

jayducharme

macrumors 601
Jun 22, 2006
4,534
5,982
The thick of it
I just completed the 4.0.1 update. Interestingly, there doesn't seem to be much change except for the bars' appearance. I still have 3 bars, as I had before. But this was interesting: I held the phone with my usual grip and (with a case on) my signal gradually dropped off to one bar -- and then rose back up to three. Previously, the phone wouldn't recover.
 

Tyre

macrumors regular
May 23, 2010
143
0
Baltimore, MD
I have no problem with a slightly taller bar for the lower signals. Personally, I think they should all be the same height and you merely count rather than the cutesy idea of graduated height.

Absolutely, or better yet how about a percentage value from 1-100? No counting, just an immediate answer.
 

potaco

macrumors regular
Mar 12, 2010
152
4
The new signal calculating formula was developed and recommended to Apply by AT&T. I'm sure AT&T is fine with Apple using their formula.

Except Apple has been lying to their customers about their actual signal. This change "fixes" that lie, but does so by making people think that AT&T is worse than previously shown (in an attempt to defer blame about the iPhone 4 antenna problems away from Apple).
 
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