Cell Phone Reception Explained: What The Bars Mean

By Matthew Braga

Spotty reception? Missing bars? Measuring signal strength is harder than you think. Underneath the GUI, here's what the numbers mean.

There's been much confusion recently when it comes to how exactly cell phone signals work. Reports that the iPhone 4 is suffering from subpar wireless reception has thrown the internet into a frenzy, with some suggesting we're simply not holding the phone correctly. Now, it seems the issue may actually lie with the phone itself — but not where you think. AnandTech is reporting that it's not necessarily the iPhone's construction that's hindering your phone calls, but the way it measures reception, fooling users into thinking the situation is worse than it really is.

As you can probably guess, this can cause problems when trying to accurately measure reception.

Obviously, you'd wonder why the iPhone wouldn't measure signal in a more linear fashion, where the decibel value for each bar is equal. The problem with this approach is that it becomes harder to diagnose a weak signal. The decibel range for five bars of reception is so large because precise measurement in such an area is less important than in areas with poor reception. The iPhone makes it easier to tell how bad your reception is in low-strength areas, but skews the measurement in places with improved coverage.

RF Signal Tracker for Android. 

Whether changes to the way the iPhone 4 measures reception will actually fix reported issues remains to be seen. Regardless, the results are an interesting look at the way cellphones handle signal strength, and with any luck, might actually result in more accurate data in the future.
Update: Believe it or not, Apple actually sent out a press release this morning, admitting what we've known all along — the iPhone has reception issues. But it's not in the hardware. Apple says the unnatural drop in reception is a direct result of the iPhone misreporting signal strength, and that the "big drop in bars is because their high bars were never real in the first place." That's the conclusion we came to, but whether more accurate measurement actually "fixes" the problem remains to be seen.

Images via Flickr user low-grade, AnandTech, androiddevelopmentproject.