beautypg.com

Configuring 802.11n – H3C Technologies H3C WA2600 Series WLAN Access Points User Manual

Page 78

background image

10-10

To do…

Use the command…

Remarks

Set the maximum number of
attempts for transmitting a frame
larger than the RTS threshold

long-retry threshold count

Optional

The default count is 4.

Specify the maximum number of
attempts to transmit a frame
shorter than the RTS threshold

short-retry threshold count

Optional

The default count is 7.

Specify the duration for the AP to
hold received packets

max-rx-duration duration

Optional

By default, the duration is 2000
milliseconds.

Configuring 802.11n

As the next generation wireless LAN technology, 802.11n supports both 2.4 GHz and 5 GHz bands. It

provides higher-speed services to customers by using the following two methods:

1) 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 work together as a

40-MHz channel. This provides a simple way of doubling the data rate.

2) Improving channel utilization through the following ways:

z

A-MPDU frame: By aggregating multiple message protocol data units (MPDUs) and using only one

PHY header for the aggregate MPDUs (A-MPDU), the overhead in transmission and the number of

ACK frames to be used are reduced, and thus improves channel utilization.

z

A-MSDU: Multiple MAC service data units (MSDU) can be aggregated into a single A-MSDU. This

reduces the MAC header overhead and thus improves MAC layer forwarding efficiency and

channel utilization.

z

Short GI function at the physical layer: This feature shortens the guard interval (GI) of 800 us in

802.11a/g to 400 us. This feature effectively reduces the channel idle time, and improves channel

utilization. The short GI feature can increase the performance by about 10 percent.

Follow these steps to configure 802.11n:

To do…

Use the command…

Remarks

Enter system view

system-view

Enter radio interface view

interface wlan-radio
interface-number

Enter radio view

radio-type { dot11an | dot11gn }

Specify the bandwidth mode for the
radio

channel band-width { 20 | 40 }

Optional

By default, the 802.11an radio
operates in 40 MHz mode; the
802.11gn radio operates in 20 MHz
mode.

Enable access permission for
802.11n clients only

client dot11n-only

Optional

By default, an 802.11a/n radio
permits both 802.11a and 802.11n
clients to access, and an 802.11g/n
radio permits both 802.11g and
802.11n clients to access.

This manual is related to the following products: