Linksys LAPAC1750PRO User Manual page 38

LAPAC1750PRO Access Point Software User Manual
Channel Select the Channel
The range of available channels is determined by the
mode of the radio interface and the country code setting
If you select Auto for the channel setting, the AP scans
available channels and selects a channel where no traffic
is detected
The channel defines the portion of the radio spectrum the
radio uses for transmitting and receiving Each mode offers
a number of channels, depending on how the spectrum
is licensed by national and transnational authorities such
as the Federal Communications Commission (FCC) or the
International Telecommunication Union (ITU-R)
When automatic channel assignment is enabled on the
Channel Management page for Clustering, the channel
policy for the radio is automatically set to static mode,
and the Auto option is not available for the Channel
field This allows the automatic channel feature to set the
channels for the radios in the cluster
Channel The 802 11n specification allows a 40 MHz-wide channel
in addition to the legacy 20 MHz channel available with
Bandwidth
other modes The 40 MHz channel enables higher data
(802 .11n and
rates but leaves fewer channels available for use by other
802 .11ac
2 4 GHz and 5 GHz devices
modes only)
The 802 11ac specification allows an 80 MHz-wide
channel in addition to the 20 MHz and 40 MHz channels
Set the field to 20 MHz to restrict the use of the channel
bandwidth to a 20 MHz channel For the 802 11ac mode,
set the field to 40 MHz to prevent the radio from using
the 80 MHz channel bandwidth
Section 3: Configuring the Access Point
Primary This setting can be changed only when the channel
bandwidth is set to 40 MHz A 40-MHz channel can be
Channel
considered to consist of two 20-MHz channels that are
(802 .11n
contiguous in the frequency domain These two 20-
modes only)
MHz channels are often referred to as the Primary and
Secondary channels The Primary Channel is used for
802 11n clients that support only a 20-MHz channel
bandwidth and for legacy clients
Select one of the following options:
• Upper — Set the Primary Channel as the upper 20-
MHz channel in the 40-MHz band
•
Lower — Set the Primary Channel as the lower 20-
MHz channel in the 40-MHz band
Short Guard This field is available only if the selected radio mode
includes 802 11n
Interval
Supported
The guard interval is the dead time, in nanoseconds,
between OFDM symbols The guard interval prevents
Inter-Symbol and Inter-Carrier Interference (ISI, ICI)
The 802 11n mode allows for a reduction in this guard
interval from the a and g definition of 800 nanoseconds
to 400 nanoseconds Reducing the guard interval can
yield a 10% improvement in data throughput
Select one of the following options:
• Yes — The AP transmits data using a 400 nanosecond
guard Interval when communicating with clients
that also support the short guard interval
•
No — The AP transmits data using an 800
nanosecond guard interval
36