I don't understand that numeric reading..
It's just the actual signal strength measurement.
The lower the number (in other words, the more negative) the worse the signal, and the higher the number (less negative) the better.
Anything above -80 is good, and would be considered full bars Anything below -110 is bad, and would be considered maybe 2 bars/dots or less.
For example, a signal number of -105 is considerably worse than a signal of -70. You?ll generally find that anything close to -105 or lower is fairly bad reception, while anything above -80 is usually good, and if you tap the number signal it?s usually shown as full bars. The full range of the signal numbers extends from -40 to -120, with -130 being a nearly impossible number to see because it means no reception, and -40 would be about the strength you?d get being right alongside a cell tower. Technically, the number goes all the way to -140, but you will almost never see that because it basically means there is no signal to speak of, and most users will see -120 or -130 before it switches over to the ?No Service? indicator instead.
Mine shows -102 most of the time inside. That's 3 bars. I walk out my door a few feet and it improves to -88 to -92. That's 4 bars. Something in my house is interfering with the signal. I go 1 mile down the road and it's -80, 5 bars. I can change it back and forth from dots to number by tapping on it.