THOMSON Gateway Configuration Manual page 16

IEEE 802.11b/g wireless Ethernet operates on the 2.4 GHz band, IEEE 802.11a operates on the 5 GHz band.
The following illustration shows the different ISM bands.
U-NII band
U-NII stands for the Unlicensed National Information Infrastructure. The FCC has made 300 MHz of spectrum
available for U-NII devices that will provide short-range, high speed wireless digital communications. The U-
NII band includes following bands:
>
U-NII 1 band or U-NII indoor (5.15 - 5.25 GHz)
>
U-NII 2 band or U-NII low (5.25 - 5.35 GHz)
>
U-NII 3 band or U-NII ISM ((5.725 - 5.825 GHz)
What is antenna diversity?
Antenna diversity is a function included in most WLAN equipment that has two antennas.
In simple terms, diversity monitors the signal from each antenna and automatically switches to the one with
the better signal. The user usually has no control over this function.
Use of directional antennas
The wireless coverage area should be fit to the desired area. Directional antennas can be used at the
perimeter directing their broadcasting inward. Some APs offer attenuation levels to be set via their web-
based setup utility.
10
Introducing Wireless Networking
f (MHz)
f (MHz)
Chapter 1
E-DOC-CTC-20060609-0001 v2.0