ZyXEL Communications PRESTIGE 2000W V2, User Manual

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P-2000W_V2 User’s Guide
Appendix D Wireless LANs 123
Figure 42 Infrastructure WLAN
Channel
A channel is the radio frequency(ies) used by IEEE 802.11a/b/g wireless devices. Channels
available depend on your geographical area. You may have a choice of channels (for your
region) so you should use a different channel than an adjacent AP (access point) to reduce
interference. Interference occurs when radio signals from different access points overlap
causing interference and degrading performance.
Adjacent channels partially overlap however. To avoid interference due to overlap, your AP
should be on a channel at least five channels away from a channel that an adjacent AP is using.
For example, if your region has 11 channels and an adjacent AP is using channel 1, then you
need to select a channel between 6 or 11.
Roaming
A wireless station is a device with an IEEE 802.11 mode compliant wireless adapter. An
access point (AP) acts as a bridge between the wireless and wired networks. An AP creates its
own wireless coverage area. A wireless station can associate with a particular access point
only if it is within the access point’s coverage area.
In a network environment with multiple access points, wireless stations are able to switch from
one access point to another as they move between the coverage areas. This is roaming. As the
wireless station moves from place to place, it is responsible for choosing the most appropriate
access point depending on the signal strength, network utilization or other factors.