Could Not Activate Cellular Data Network

iPhone 5 Error message: Could not activate cellular data network

Ever had this problem?

You’ll notice one other thing about the display on the iPhone.

As you look atop the image, you’ll see numbers instead of the “bars” used to display signal strength. The number -103 is a numerical signal strength indicator, which the proper, and only way to indicate signal strength.

Just in the case you’re not aware of the technical aspects of signal strength, or what the number means, signal strength is measured as a loss.

The number itself is a numerical indicator that measures dBm, or decibels per milliwatt, and may also be referred to as a “S meter.”

In other words, a perfectly strong signal has no loss (zero loss). That is to say, 100% of the signal being sent is being received. A signal of lesser strength would be -30. And yet, comparatively, that would be a strong signal. As shown here, a signal strength of -103dBm is not a powerful signal, and compared with a hypothetical signal strength of -30dBm would be nearly three times weaker.

A signal strength of -103 has an effective power of 5.0118723363 e-14 watts. Numerically expressed, that would be -0.37631850167.

A signal strength of -30 has an effective power of 0.000001 watts. Numerically expressed, that would be 0.000001.

Notice the difference between the numerical expression of the effective power of the two numbers. One is NEGATIVE, while the other is POSITIVE.

For some comparison, an ideally strong received cellular signal strength is -10dBm, whereas a typical GPS signal is nearly -130 (-127.5dBm).

The measurement scale is a logarithmic one. That is to say, that a doubling of one number (for example, 3) which is 6, is the same power value as doubling 10, which is 20.

And yet, the distance between 3 and 10 (which is 7), is NOT the same distance between 3 and 6 (which is 3). But because the distance between 3 and 6 is double, the distance between 10 and 20 (which is 10) is expressed as having the same value.

If you’re not mathematically minded, not to worry. I’m just trying to explain logarithms – the relationship one number has to another. More specifically, it is the answer to the question “how many times must a number be increased in order to get to another number?”

Anyway…

Think of signal strength this way: The higher the negative number, the weaker the signal.

Pretty easy, eh?

Oh… and how to get that numerical signal indicator, instead of seeing the crappy, useless “bars”?

That’s for another entry.

Until then…