ZyXEL Communications Corporation G470 Manuel D’Utilisation

G-470 User’s Guide

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Chapter 6 Wireless Screens

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

This section describes the wireless LAN network terms.

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.