H3C Technologies H3C WX3000E Series Wireless Switches User Manual

Page 379

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363

Item Description

802.11g
Protection

Mode

RTS/CTS—Use RTS/CTS mode to implement 802.11g protection. Before
sending data to a client, an AP sends an RTS packet to the client, ensuring

that all the devices within the coverage of the AP do not send data in the

specified time after receiving the RTS packet. Upon receiving the RTS
packet, the client will send a CTS packet again, ensuring that all the

devices within the coverage of the client do not send data in the specified

time.

CTS-to-Self—Uses CTS-to-Self mode to implement 802.11g protection.

When an AP sends packets to a client, it uses its IP address to send a CTS

packet to inform the client that it will send a packet, ensuring that all the
devices within the coverage of the AP do not send data in the specified

time.

802.11g
Protection

802.11b devices and 802.11g devices use different modulation modes, so
802.11g protection needs to be enabled for a 802.11g device to send

RTS/CTS or CTS-to-self packets to 802.11b devices, which will defer access
to the medium.
An AP running 802.11g uses the 802.11g protection function in the
following two cases:

An 802.11b client is associated with it.

It detects APs or clients running 802.11b on the same channel.

Enable—Enable 802.11g protection.

Close—Disable 802.11g protection.

IMPORTANT:

Enabling 802.11g protection reduces network performance.

Enabling 802.11g protection applies to the second case only, because

802.11g protection is always enabled for the first case.

802.11n
Protection

Mode

Both RTS/CTS and CTS-to-Self modes can be adopted. The implementation
of the two modes is the same as 802.11g.

802.11n
Protection

Enable—Enables 802.11n protection. When non 802.11n wireless devices

or non 802.11n clients exist within the coverage of the AP, you need to
enable 802.11n protection.

Close—Disables 802.11n protection.

Channel
Setup

Note the following guidelines when configuring channel adjustment:

Before configuring channel adjustment, make sure that the AC adopts the auto channel

adjustment mode (for more information, see "

Configuring radio parameters

."). Otherwise,

channel adjustment does not work.

If you lock the channel first, and then enable channel adjustment (by selecting Dynamic

Channel Select), channel adjustment does not work because the channel is locked. Before
enabling channel adjustment, make sure that the channel is not locked.

If you enable channel adjustment and then lock the channel, the last selected channel is
locked.

For how to lock the channel, see "

Locking the channel

."

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