By using a key combination, a BlackBerry user can convert the cellular and wifi meter bars into numbers. This allows for more accurate testing of cellular and wifi strength. Heck, now the BlackBerry actually has a free wifi signal meter included.
Users are very familiar with the bar meters used to demonstrate the signal strength of the wifi and cellular networks. However, for testing and debugging, seeing the actual numbers instead is much more helpful.
To see the actual signal strength numbers on your BlackBerry device:
1. Hold down the alt key
2. Type the following keys NMLL
3. The cellular and wifi meters will now be converted to numbers.
4. Repeat the key combo to return the numbers to graphs.
Any greater than -80dBm is excellent strength. The scale is based on a logarithmic scale so don’t let the negative numbers fool you. -40dBm, for example, is practically perfect coverage.
Anything less than -100dBm and you probably will not have coverage.
I enjoyed enabling this feature and then walking around my house to find the areas of good and poor signal strength.