Appendix B - About Wireless LANs
performance. This capability is called
Roaming
. (Access Points do not have or require
Roaming capabilities.)
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 which provides the least interference and best perform-
ance. In the USA and Canada, 11 channel are available. If using multiple Access
Points, it is better if adjacent Access Points use different Channels to reduce inter-
ference.
•
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 Chan-
nels 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 transmit-
ted.
This is desirable because it is impossible to prevent snoopers from receiving any data
which is transmitted by your Wireless Stations. But if the data is encrypted, then it is
meaningless unless the receiver can decrypt it.
If WEP is used, the Wireless Stations and the Access Point must have the same
settings for each of the following:
WEP
Off, 64 Bit, 128 Bit
Key
For 64 Bit encryption, the Key value must match.
For 128 Bit encryption, the Key value must match
WEP Authentication
Open System or Shared Key.
WPA-PSK
WPA-PSK is another standard for encrypting data before it is transmitted. This is a
later standard than WEP (Wired Equivalent Privacy), and provides greater security for
your data. Data is encrypted using a 256Bit key which is automatically generated and
changed often.
If all your Wireless stations support WPA-PSK, you should use this instead of WEP.
If WPA-PSK is used, the Wireless Stations and the Access Point must have the
same settings for each of the following:
WPA PSK
(Pre-shared Key)
Enter the same value on every station and the AP.
The PSK must be from 8 to 63 characters in length.
The 256Bit key used for the actual encryption is de-
rived from this key.
125
