ZyXEL Communications G-470, User Manual

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G-470 User’s Guide
56 Chapter 6 Wireless Screens
6.1.2 ESS
An Extended Service Set (ESS) consists of a series of overlapping BSSs, each containing an
access point, with each access point connected together by a wired network. This wired
connection between APs is called a Distribution System (DS). An ESSID (ESS IDentification)
uniquely identifies each ESS. All access points and their associated wireless stations within
the same ESS must have the same ESSID in order to communicate.
Figure 27 Extended Service Set
6.2 Wireless LAN Basics
This section describes the wireless LAN network terms.
6.2.1 Channel
A channel is the radio frequency or frequencies used by IEEE 802.11b 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 from an adjacent AP (access point) to
reduce interference. Interference occurs when radio signals from different access points
overlap, causing signal disruption 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.