So, Apple have published a press release addressing the infamous iPhone 4 reception issue:
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 donâ€™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.
Weird. I imagine that signal-strength calculation is a difficult algorithm to crack, and subject to a large degree of uncertainty — just as power calculation and runtime calculation are difficult algorithms to crack — but it's a little odd that Apple would get this wrong and fail to fix it before now. The press release claims the error has been around since the original iPhone launched, which makes me thing the software issue is a relatively minor one. Obviously signal degradation is a real problem on the iPhone 4, though not nearly as widespread and devastating as some make it out to be. As Apple mention in their press release, this is an issue that affects all mobile devices; and although I'd wager that signal strength on the iPhone 4 is measurably more affected by the placement of one's hand relative to the antenna given it's unique design (which seems to more than make up for any degredation, but probably makes the signal strength prone to prominent fluctuations) it certainly doesn't look like a faulty product. Anyway, it looks like the imminent software update is one part bug fix, one part fig leaf and probably all unnecessary but at least it should cool the hysteria a little.