Apple Releases iOS 4.0.1 with Cell Signal Patch

| News

Apple released iOS 4.0.1 for the iPhone and iPod touch on Thursday with the promised signal strength bar patch. The update includes a new signal bar algorithm that Apple claims is more accurate along with redesigned bar graphics intended to make it easier for users to see.

Apple previously said the formula is uses to calculate cell signal strength is inaccurate and shows artificially high signal strength on the iPhone 3G, 3GS and 4. In an open letter, the company promised a fix was on the way.

The update is available via Apple’s iTunes application on the Mac and Windows, and is available for free.



was it released for the iPod touch ? I wonder what signals does it calculate smile ?


Just to be clear: this is a Cell Signal indicator patch, not a cell signal patch. The supposed software “fixes” for the iPhone 4 that update the radio controller software (“baseband”) are included in 4.1, which has been released to devs for beta testing.


Installed the patch. My iPhone seems snappier!

(Actually it doesn’t, but I couldn’t resist.)


At almost 580MB I suspect it’s more than just a patch to change the way the bars are calculated.


I suspect it?s more than just a patch to change the way the bars are calculated

Do your own research then wink In an OS X update, you only download what has changed and the OS intelligently places things where they belong. Because of the way that iPhone software updates work (aka the way all of the anti-hacking code checks work), the entire base OS has to be wiped and re-uploaded from a newly encrypted file onto the iPhone OS partition. This means that when you do a simple update such as this 4.0.1 update, you still have to download an entire copy of iOS 4 again, it’s just repackaged in a sense.

Obviously that would make no sense for something like OS X because nobody wants to download 5GB update files. However since iOS is only(?) around 500MB, Apple has made these “hotfix” bite size upgrades impossible. The primary reason (in my well-researched opinion) for this behavior is that Apple doesn’t want hackers to be able to easily install their own custom “updates” to the device, such as unlocking programs and Google Voice apps.

A more easily observable fact that proves this without having to research the partition and checksumming schemes of iOS is that the same 500MB “update” file that you downloaded can also be used as a “restore” file to completely wipe your iPhone and reinstall the OS.

In iOS 4.1 for iPhone 4 however, there is a new version of the radio controller software (called the baseband). I have not tested this new baseband on my iPhone yet, so I don’t know how much of an actual difference it makes, but 4.1 should at least make a theoretical difference if not an actual one, unlike 4.0.1, which uses the exact same baseband as 4.0.

Edit: I hope I don’t come off as a smug nerd here, I’m just trying to help and educate smile


Well, I’m gonna install it on my Touch. My battery life can’t get worse, so what the hell. It’s worth a shot. I’ll post any results in the thread I started in the forums.


Update: So much for that. Must be only Gen3 iPod Touch’s. It says mine is up to date.
Oh well. Back to airplane mode…

Lee Dronick

Last evening I installed it on my iPhone 3G. I live about 800-900’ from a AT&T cell tower and previously my iPhone showed 5 bars and now it shows 2. My wife also has an iPhone 3G that does not have iOS 4 unstalled and it shows 5 bars. No difference in calls, just a difference in bars displayed.

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