About Wireless Lans; Modes; Bss/Ess; Channels - ZyXEL Communications P-330W User Manual

Appendix B
A b o u t W i rel es s L A N s
This Appendix provides some background information about using Wireless
LANs (WLANs).

Modes

Wireless LANs can work in either of two (2) modes:
•
Ad-hoc
•
Infrastructure
Ad-hoc Mode
Ad-hoc mode does not require an Access Point or a wired (Ethernet) LAN. Wireless
Stations (e.g. notebook PCs with wireless cards) communicate directly with each other.
Infrastructure Mode
In Infrastructure Mode, one or more Access Points are used to connect Wireless Stations
(e.g. Notebook PCs with wireless cards) to a wired (Ethernet) LAN. The Wireless Stations
can then access all LAN resources.
Access Points can only function in "Infrastructure" mode,
and can communicate only with Wireless Stations which are
set to "Infrastructure" mode.
BSS
BSS
A group of Wireless Stations and a single Access Point, all using the same ID (SSID), form a
Basic Service Set (BSS).
Using the same SSID is essential. Devices with different SSIDs are unable to communicate
with each other.

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 performance. 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 interference.
•
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.)
B