iPhone Screen Shots: Call Failure

Has this ever happened to you?

The dreaded, inevitable "Call Failure" screen.

Note the signal strength indicator.

It is a numeric indicator, rather than a pictographic icon. That’s how signal strength is indicated – with a negative number. The lower the number (closer to zero), the stronger the signal. The higher the number (further away from zero), the weaker the signal.

Put another way, signal strength is actually measured as signal loss. To illustrate, it makes sense that the closer you are to someone whom is speaking in a normal tone of voice, the easier it is to hear them. The further away you are from someone whom is speaking in a normal tone of voice, the more difficult it is to hear them. The scientific measure of signal strength – as shown measured in this screenshot – measures how much loss of the original signal’s strength has occurred.