According to the CWNA website, RF technologies represent about one quarter of the CWNA exam. This includes learning how to apply RF math concepts like Watt/ Milliwatt, Decibel (dB), and gain / loss (dBm and dBi) to calculate WLAN power at the transmitter, between transmitter and antenna, and emitted by the antenna (EIRP). Although power conversion formulas include logarithms, the CWNA exam won't test your understanding of logarithmic functions -- instead, you'll use "rules of thumb" like this one: +3dB doubles the watt value; -3dB cut the watt value in half. In short, you'll only be required to demonstrate that you understand how WLAN components combine to determine RF power output and relationships between associated units of measurement.
This was first published in May 2005