Operation Manual

Frequency Range
52 FRITZ!Box Fon WLAN – 8 WLAN: Wireless Local Area Networks
8.3 Frequency Range
WLAN uses the frequency range around 2.4 GHz in the ISM
band. WLAN thus works in the high-frequency range, like
Bluetooth. Microwave devices and cordless telephones use
this range as well. Thus interference can occur within WLANs
operated in the vicinity of such devices. Generally the only
adverse effects are to the transmission rate; aborted connec-
tions and data losses are rare.
In Europe, 13 channels are provided for WLAN in the 2.4 GHz
range. One channel has a bandwidth of 22 MHz. A 5-MHz in-
terval is left empty between adjacent channels. That means
that channels located directly next to each other can overlap
and result in mutual interference. If several WLANs are oper-
ated within a small space, a distance of at least 5 channels
should be left empty between each two channels used. For
instance, if channel 1 is selected for one WLAN, the channels
7 through 13 can be selected for a second WLAN. This main-
tains the minimum distance between channels.
Should interference in a WLAN persist, the first step should
be to select a different channel. Additional tips on interfer-
ence in the WLAN radio network are presented in the section
“Eliminating Disturbances caused by Another WLAN Radio
Network” from page 70.
WLAN channels in the 2.4 GHz range:
Channel Frequency (MHz) Channel Frequency (MHz)
1 2412 8 2447
22417 92452
3 2422 10 2457
42427 112462
5 2432 12 2467
62437 132472
7 2442