Does iOS 4.0.1 make a difference?

Last Thursday, just before Apple called a press conference to address concerns with the iPhone 4’s antenna, the company issued its promised 4.0.1 software update. The release didn’t offer new features, and it didn’t change anything about the controversial antenna, but it did alter how bars are displayed on the handset’s signal meter. CNET has spent the last few days testing the update to determine what it means for you. But before we get to our findings, a bit of background is necessary.

Apple iPhone 4
Josh Miller/CNET

The back story
Apple first promised the update on July 2, 2010, in response to reports from users and reviewers (CNET included) that the iPhone 4 was dropping bars when people covered a gap in the phone’s antenna with their hands. In a statement, Apple said it was “stunned” to learn the bar drop was caused by an incorrect display of the phone’s true signal strength.

Due to this incorrect formula, users in low reception areas were mistakenly seeing an additional two bars of reception. “Users observing a drop of several bars…are most likely in an area with very weak signal strength, but they don’t know it because we are erroneously displaying 4 or 5 bars,” the company said. Apple then promised that the forthcoming update would adopt AT&T’s recently recommended formula to more accurately display the signal strength, and would enlarge the first three bars to make them easier to see.

Making sense of it all
After the release went out, we heard from many CNET users who were confused about how iOS 4.0.1 would change their user experience. And to be honest, we didn’t know what to expect when we first got it either. So to find out how the update affects everyday usability, we took two iPhone 4s–one had the update and one did not–and compared the number of displayed bars in 10 places in San Francisco. We chose three locations with historically Average reception (two to three bars using the old standard), three places with poor reception (no coverage to two bars), one place with good reception (no more than four bars) and three locations with Excellent service (a full five bars).

In four of the ten locations tested, the unaltered iPhone 4 displayed more bars than its updated sibling. In four other places, however, we saw no difference. And most interestingly, in two of the three locations with the poorest reception, the updated iPhone displayed more bars than the handset without the update.

How we did it
To conduct the tests, we held the handsets in identical positions in the chosen locations and took screenshots at the same time to record our observations. We also tried (up to three times) to place a call. To exclude any interference from attenuation or the “death grip,” we made sure not not to cover the antenna gap.

Though the number of bars isn’t the best measure of true reception–Apple still hasn’t told us why it removed the Field test App–we used bars in this comparison because the update was specifically designed to change them. Also, the signal strength meter is the measure on which users rely most. We understand that other variables may be affecting reception, and that even two phones with the update can show a different number of bars simultaneously, but we wanted to discover if iOS 4.0.1 did what it promised.

Editors’ note: In all screenshot images, the updated iPhone 4’s signal meter is above that of the handset without the update.

Location 1

Where: Intersection in Financial District during afternoon commute
Typical reception: Excellent
Updated iPhone 4: 5 bars
Unaltered iPhone 4: 5 bars
Could we make a call? Yes for both phones