Frequency Ranges
33
2.3
Frequency Ranges
WLAN uses the frequency range around 2.4 GHz in the ISM
band or, alternatively, the frequency range at 5 GHz.
2.4-GHz Frequency
Band
In the 2.4-GHz frequency band WLAN works in the same
range as Bluetooth, microwave devices and various other
devices like some cordless telephones, radio-controlled
toys, garage-door openers and video bridges. This means
that interference may occur within WLANs operated in the
vicinity of such devices. Generally the only adverse effects
are to the transmission rate; aborted connections and da-
ta losses are rare.
WLAN in the 5-GHz frequency band is subject to less inter-
ference, as these radio frequencies are used much less of-
ten.
In the 2.4-GHz frequency range the European regulation
authorities have designated 13 channels for WLAN.
A channel can have a bandwidth of 20 MHz (throughput
up to 130 Mbit/s) or 40 MHz (throughput of up to
300 Mbit/s).
Channels located directly next to each other in the 2.4-
GHz band may overlap and result in mutual interference.
For instance, if several WLANs are operated close to each
other in the 2.4-GHz frequency range with a bandwidth of
20 MHz, a distance of at least five channels should be left
empty between each two channels used. This means that
if channel 1 is selected for one WLAN, the channels 6
through 13 can be selected for a second WLAN. This main-
tains the minimum distance between channels.
If your WLAN access point is equipped with an autochan-
nel function, you can automatically have it search for a
WLAN channel in your frequency range that is subject to as
little interference as possible.
In order to communicate with each other, the
FRITZ!WLAN Repeater and the WLAN access point must
work in the same frequency band.
