40
Frequency Ranges
9.3 Frequency Ranges
WLAN uses the frequency ranges at 2.4 GHz and 5 GHz as its
transmission range.
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 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 this has ad-
verse effects on the transmission rate, including aborted con-
nections.
WLAN in the 5-GHz frequency band is subject to less interfer-
ence, as these radio frequencies are used much less often.
In the 2.4-GHz frequency range the European regulation au-
thorities have designated 13 channels for WLAN. A channel
can have a bandwidth of 20 MHz (throughput of 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 in-
stance, 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 be-
tween 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 maintains the minimum dis-
tance between channels.
Should interference in a WLAN persist, the first step should
be to select a different channel.
If your WLAN remote sites support the WPA security mecha-
nisms, use WPA for your WLAN encryption. WEP is out of
date and data encrypted with WEP can be deciphered with-
in minutes.
The frequency range used in your WLAN depends on the set-
tings of your WLAN access point.
N_man_en.fm Seite 40 Freitag, 27. Mai 2016 2:21 14
To Next Page
Loading...
