AVM Fritz!Box 3390, Руководство по конфигурации и эксплуатации

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FRITZ!Box 3390 90
Wireless LAN—Getting Technical
In the 2.4-GHz frequency range the European regulation au-
thorities have designated 13 channels for wireless LAN.
A channel can have a bandwidth of 20 MHz (throughput of up
to 216 Mbit/s) or 40 MHz (throughput of up to 450 Mbit/s).
Channels located directly next to each other in the 2.4-GHz
band may overlap and result in mutual interference. For in-
stance, if several wireless networks 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 wireless network, the
channels 6 through 13 can be selected for a second wireless
network. This maintains the minimum distance between
channels.
Should interference in a wireless network persist, the first
step should be to select a different channel.
WLAN Autochannel
With the WLAN autochannel function, the FRITZ!Box automati-
cally searches for the channel subject to the least interfer-
ence. This process takes into consideration interference from
radio networks in the vicinity (wireless LAN access points)
and potential sources of interference (for instance video
bridges, baby monitors, microwave ovens). Should problems
with interference persist despite this function, try to identify
the source of interference and switch it off manually.
5-GHz Frequency Band
The FRITZ!Box can operate in parallel in the 5-GHz frequency
band. This frequency range is used much less often than the
most common 2.4-GHz frequency range.
In the 5-GHz frequency band the FRITZ!Box supports automat-
ic channel switching by DFS (Dynamic Frequency Selection).
DFS ensures that the channels from 52 to 140 are kept free
for higher-priority users, like weather radar systems. If you
are operating your FRITZ!Box in one of these channels, it mon-
itors the selected channel periodically for higher-priority us-
ers, and, if necessary, switches to a different channel. Note
that the FRITZ!Box waits up to ten minutes, as legally re-