Apple responds to criticism of iPhone 4's mobile reception

Apple Inc today issued an open letter on the subject of mobile reception strength in iPhone 4, in response to criticism of the recently launched smartphone’s antennae design.

It follows a week of public debate across the internet, as disgruntled iPhone 4 users claimed that human skin contact changes the electrical properties of the antennae. Dozens of videos demonstrating the issue have been posted to YouTube.

The iPhone 4 has its antennae on the outside of the phone, rather than the inside, and the problem is compounded by the position being at the base of the unit rather than at the top. The logic behind this is to minimise radio output near the user’s head, which in turn enables a device to more readily pass safety testing by the US Federal Communications Commission (FCC).

Companies offering iPhone accessories, such as silicon cases and covers, have reported increased sales, as a thin layer of a synthetic material minimises the problem. Apple itself offers Bumpers, which are bright-coloured silicon bands that wrap around the frame of the iPhone 4, although at £29 they are not cheap.

However, Apple’s letter states that the problem is not due to the antennae design; rather, Apple claims that the problem is due to the formula used in the iPhone software to calculate signal strength.

Apple’s conclusion is that this has resulted in iPhones incorrectly reporting signal strength.

The letter states: “We have gone back to our labs and retested everything, and the results are the same: the iPhone 4’s wireless performance is the best we have ever shipped.”

The following is the “Letter from Apple” press release in full.

July 2, 2010
Letter from Apple Regarding iPhone 4

Dear iPhone 4 Users,

The iPhone 4 has been the most successful product launch in Apple’s history. It has been judged by reviewers around the world to be the best smartphone ever, and users have told us that they love it. So we were surprised when we read reports of reception problems, and we immediately began investigating them. Here is what we have learned.

To start with, gripping almost any mobile phone in certain ways will reduce its reception by 1 or more bars. This is true of iPhone 4, iPhone 3GS, as well as many Droid, Nokia and RIM phones. But some users have reported that iPhone 4 can drop 4 or 5 bars when tightly held in a way which covers the black strip in the lower left corner of the metal band. This is a far bigger drop than normal and as a result some have accused the iPhone 4 of having a faulty antenna design.

At the same time, we continue to read articles and receive hundreds of emails from users saying that iPhone 4 reception is better than the iPhone 3GS. They are delighted. This matches our own experience and testing. What can explain all of this?

We have discovered the cause of this dramatic drop in bars and it is both simple and surprising.

Upon investigation, we were stunned to find that the formula we use to calculate how many bars of signal strength to display is totally wrong. Our formula, in many instances, mistakenly displays 2 more bars than it should for a given signal strength. For example, we sometimes display 4 bars when we should be displaying as few as 2 bars. Users observing a drop of several bars when they grip their iPhone in a certain way 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. Their big drop in bars is because their high bars were never real in the first place.

To fix this, we are adopting AT&T’s recently recommended formula for calculating how many bars to display for a given signal strength. The real signal strength remains the same, but the iPhone’s bars will report it far more accurately, providing users a much better indication of the reception they will get in a given area. We are also making bars 1, 2 and 3 a bit taller so they will be easier to see.

We will issue a free software update within a few weeks that incorporates the corrected formula. Since this mistake has been present since the original iPhone, this software update will also be available for the iPhone 3GS and iPhone 3G.

We have gone back to our labs and retested everything, and the results are the same: the iPhone 4’s wireless performance is the best we have ever shipped. For the vast majority of users who have not been troubled by this issue, this software update will only make your bars more accurate. For those who have had concerns, we apologise for any anxiety we may have caused.

As a reminder, if you are not fully satisfied, you can return your undamaged iPhone to any Apple Retail Store or the online Apple Store within 30 days of purchase for a full refund.

We hope you love the iPhone 4 as much as we do.

Thank you for your patience and support.


Earlier this week, Apple announced that it had sold over 1.7 million iPhone 4 units by the end of Saturday 26 June 26, three days after its launch.

The device features FaceTime video calling; Apple’s new Retina display, which the company claims is the highest resolution display ever built in to a phone; a five megapixel camera with LED flash; HD 720p video recording; Apple’s A4 processor; a three-axis gyro and an estimated 40 per cent longer talk time courtesy of an improved battery.

The software on the phone – iOS 4 – finally makes multitasking possible, a long-standing user request, introduces Folders, an enhanced version of Mail, deeper Enterprise support and Apple’s new iAd mobile advertising platform.

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