Apple recently released iOS 4.0.1 to the public and iOS beta 4.1 to the development community, with the most noticeable changes being in the signal strength indicator. What do these changes really mean to the iPhone owner?
Quite literally, it means less bars in more places. As seen in the graphic above, an iPhone running iOS 4.0 showed 5 bars the majority of the time. Very rarely did it display 1 or 4 bars, and it almost never showed 2 or 3 bars. When comparing it to the new figures, we can see a definite change. For example, an iPhone with a -92 dBM signal would show 5 bars if it was running iOS 4.0, while iOS 4.0.1 would only show 3. This may cause an uninformed iPhone 4 owner to think they "lost" a bar or two in signal strength after the upgrade when the change is truly only cosmetic. It is also worth noting that the minimum signal strength required to show one bar has been lowered. This is because Apple claims that the iPhone 4 can still operate with a signal strength as low as -121 dBm.
Another thing you may notice is a change in how the bars are displayed. The lower bars are all noticeably taller with the updated OS. Apple made this change for "visibility" reasons, but one could argue that they are just trying to make the bars seem more "optimistic."
While none of these changes will make the phone work any better, Apple argues this will help iPhone owners to get a more honest understanding of the signal strength on their iPhone. Judge for yourself; iOS 4.0.1 is now available through iTunes.
[Source: Anandtech via MacRumors]