I don't often feature vendor newsletters, but this morning I got this newsletter from B&B Electronics, in Ottawa IL.

http://links.bandbelectronics.mkt1781.com/servlet/MailView?ms=MzkwMDczMzIS1&r=NTgwMzEzOTYzNwS2&j=MTM3MjM0OTgyS0&mt=1&rt=0

The two definitions of packet sniffers are great, but the best of the newsletter is the link to "The Ten Commandments of Wireless Connectivity" also on their site. This is a great read, and very valuable information.

I offer just the first one here, to whet your whistle. The rest you will have to read on B&B's website.

1. Thou shall know thy dBm and recall thy high school logarithms.

Radio Frequency (RF) power is measured in milli Watts (mW) or, more usefully, in a logarithmic scale of decibels (dB), or decibels referenced to 1 mW of power (dBm). Since RF power attenuates as a logarithmic function, the dBm scale is most useful. Here are some examples of how these scales relate:

1mW = 0dBm 2mW = 3dBm 4mW = 6dBm 10mW = 10dBm 100mW = 20dBm 1W = 30dBm   Visit B&B Electronics for the next nine commandments.

A 2-fold increase in power yields 3dB of signal. A 10-fold increase in power yields 10dB of signal. A 100-fold increase in power yields 20dB of signal.