H3C Technologies H3C MSR 50 - Manual (Page 26)

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As the next generation wireless LAN technology, 802.11n supports both 2.4-GHz and 5-GHz bands. It
provides higher throughput by using the following methods:
• Increasing bandwidth: 802.11n can bond two adjacent 20-MHz channels together to form a
40-MHz channel. During data forwarding, the two 20-MHz channels can work separately with one
acting as the primary channel and the other acting as the secondary channel or working together
as a 40-MHz channel. This provides a simple way of doubling the data rate.
• Improving channel utilization through the following ways:
{
802.11n introduces the A-MPDU frame format. By using only one PHY header, each A-MPDU
can accommodate multiple MPDUs which have their PHY headers removed. This reduces the
overhead in transmission and the number of ACK frames to be used, and improves network
throughput.
{
Similar with MPDU aggregation, multiple MSDU can be aggregated into a single A-MSDU.
This reduces the MAC header overhead and improves MAC layer forwarding efficiency.
{
To improve physical layer performance, 802.11n introduces the short GI function, which
shortens the GI interval of 800 ns in 802.11a/g to 400 ns. This can increase the data rate by
10 percent.
To configure 802.11n:
Step Command Remarks
91. Enter system view. system-view N/A
92. Enter AP template view.
wlan ap ap-name [ model
model-name [ id ap-id ] ] Specify the model name only when
you create an AP template.
93. Enter radio view.
radio radio-number type { dot11an
| dot11gn }
N/A
94. Specify the bandwidth mode
for the radio.
channel band-width { 20 | 40 }
Optional.
By default, the 802.11gn radio
operates in 20 MHz mode.
95. Enable access permission
only for 802.11n clients .
client dot11n-only
Optional.
By default, an 802.11gn radio
permits both 802.11b/g and
802.11gn clients to access.
96. Enable the short GI function. short-gi enable
Optional.
By default, the short GI function is
enabled.
97. Enable the A-MSDU function. a-msdu enable
Optional.
By default, the A-MSDU function is
enabled.
The device receives but does not
send A-MSDUs.
98. Enable the A-MPDU function. a-mpdu enable
Optional.
By default, the A-MPDU function is
enabled.
For information about Modulation and Coding Scheme (MCS) index and mandatory and supported
802.11n rates, see "Configuring WLAN RRM."