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As wireless stations are physically moved through the area covered by an ESS, they will
automatically change to the access point that has the least interference or best performance.
This capability is called Roaming. (Access points do not have or require roaming capabili-
ties.)
Channels
The wireless channel sets the radio frequency used for communication.
•
Access points use a fixed channel. You can select the channel used. This allows you
to choose a channel that provides the least interference and best performance. For
USA and Canada, the following channels are available.
2.4GHz:
2.412 to 2.462 GHz; 11 channels
5GHz:
•
5.180 to 5.320 GHz; 8 channels
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5.500 to 5.700 GHz, 8 channels (excludes 5.600 to 5.640 GHz)
•
5.745 to 5.825 GHz; 5 channels
•
If using multiple access points it is better if adjacent access points use different
channels to reduce interference. The recommended channel spacing between adjacent
access points is five channels, e.g., use Channels 1 and 6, or 6 and 11.
•
In "Infrastructure" mode wireless stations normally scan all channels looking for an
access point. If more than one access point can be used, the one with the strongest
signal is used. (This can only happen within an ESS.)
•
If using "Ad-hoc" mode (no access point) all wireless stations should be set to use the
same channel. However, most wireless stations will still scan all channels to see if
there is an existing "Ad-hoc" group they can join.
WEP
WEP (Wired Equivalent Privacy) is a standard for encrypting data before it is transmitted. This
is desirable because it is impossible to prevent snoopers from receiving any data which is
transmitted by your wireless stations. If the data is encrypted, it is meaningless unless the
receiver can decrypt it.
If WEP is used, the wireless stations and the wireless access point must have the same
settings.
WPA-PSK
In WPA-PSK, like WEP, data is encrypted before transmission. WPA is more secure than
WEP. The PSK (Pre-shared Key) must be entered on each wireless station. The 256-bit
encryption key is derived from the PSK, and changes frequently.
WPA2-PSK
This is a further development of WPA-PSK, and offers even greater security, using the AES
(Advanced Encryption Standard) method of encryption. It should be used if possible.
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