Frequency
As previously mentioned, an RF signal cycles in an alternating current in the form of an electromagnetic wave. You also know that the distance traveled in one signal cycle is the wavelength. But what about how often an RF signal cycles?
Frequency is the number of times a specified event occurs within a specified time interval.
A standard measurement of frequency is hertz (Hz), which was named after the German physicist Heinrich Rudolf Hertz. An event that occurs once in 1 second is equal to 1 Hz. An event
How Does the Wavelength of a Signal Concern Me?
Because the wavelength property is shorter in the 5 GHz frequency range, Wi-Fi equipment
using 5 GHz radio cards will have shorter range and coverage area than Wi-Fi equipment using
2.4 GHz radio cards.
Part of the design of the wireless LAN includes what is called a site survey. Part of the
responsibility of the site survey is to determine zones, or cells, of usable signal coverage in
your facilities. The 2.4 GHz access points will provide greater RF footprints than the higherfrequency equipment simply because of the wavelengths of the two different frequency signals. More 5 GHz access points may have to be installed to meet the same coverage needs
that are achieved by a lesser number of 2.4 GHz access points.
Inches: wavelength = 11.811/frequency (GHz)
Centimeters: wavelength = 30/frequency (GHz)
that occurs 325 times in 1 second is measured as 325 Hz. The frequency at which electromagnetic waves cycle is also measured in hertz. Thus, the number of times an RF signal cycles in
1 second is the frequency of that signal.