User Guide

Table Of Contents
Bridge GUI Guide: Network Configuration
63
and block acknowledgement (block ACK), and smaller frame
headers and inter-frame gaps.
On 802.11n-capable radios, there are three possible high-
throughput (
ht) 802.11n options for each frequency band
supported on the radio: three for the 5 GHz
802.11na band and
three for the 2.4 GHz
802.11ng band, when present:
ht20 - 802.11n - High-Throughput 20 MHz, the radio will use
only 20 MHz channel widths, while taking advantage of the
standard’s traffic handling efficiencies.
ht40plus - High-Throughput 40 MHz plus 20 MHz, the radio
can use 40 MHz channel widths by binding the selected
20 MHz channel to the adjacent 20 MHz channel above it
on the radio spectrum.
ht40minus - High-Throughput 40 MHz minus 20 MHz, the
radio can use 40 MHz channel widths by binding the
selected 20 MHz channel to the adjacent 20 MHz channel
below it on the radio spectrum.
3.3.2.3 Channel and Channel Width
The
Channel setting selects the portion of the radio spectrum
the radio will to use to transmit and receive—in order to provide
wireless LAN access or to establish the initial connections in a
mesh network.
NOTE: Consult
your local regula-
tory authority for appli-
cable radio device and
transmission rules and
for DFS channel desig-
nations.
The channels available for user selection are determined by
the frequency band the radio uses, subject to the relevant
regulatory domain rules. In most regulatory domains, certain
channels in the 5 GHz frequency band are designated DFS
(Dynamic Frequency Selection) channels. DFS compliance
also restricts the channels available for user selection (and
broadcast) on 802.11a radios.
The Bridge GUI presents only currently permissible channels
for user selection, according to the currently specified
Country
of operation (Section 3.3.1.3) and
Band (Section 3.3.2.2),
excluding channels on the radio’s
DFS Channel Exclusions list
(Section 3.3.3).
A dual-band radio that uses the 2.4 GHz 802.11g band by
default (Radio 1 in the multiple radio ES440, ES520 and ES820
Bridges) is set to channel
1 by default.
A second internal 5 GHz 802.11a radio (Radio 2 in non-military-
band ES440, ES520 and ES820) or a single dual-band radio
that uses 802.11a by default (Radio 1 in the ES210) has a
default channel setting of
149. In the military-band ES440,
Radio 2 is set to channel
4100 by default.
Whether they use the 5 GHz 802.11a band or the 4.4 GHz
military band, Radio 3 and Radio 4 in the ES440 are set by
default to unique channels.