Cisco 9971 Deployment Manual page 48

Use the short preamble setting in the 2.4 GHz radio configuration setting on the access point when no legacy clients that require
a long preamble are present in the wireless LAN. By using the short preamble instead of long preamble, the wireless network
performance is improved.
If using 2.4 GHz, ensure the 802.11b/g network status and 802.11g is set to enabled.
Set the beacon period to 100ms.
Use the short preamble setting in the 2.4 GHz radio configuration setting on the access point when no legacy clients that require
a long preamble are present in the wireless LAN. By using the short preamble instead of long preamble, the wireless network
performance is improved.
Ensure DTPC Support is enabled.
If using 802.11n capable access points, ensure ClientLink is enabled.
Configure 12 Mbps as the mandatory (basic) rate and 18 – 24 or 54 Mbps as supported (optional) rates assuming that there will
not be any 802.11b only clients that will connect to the wireless LAN.
If there are existing 802.11b clients, then 11 Mbps should be set as the mandatory (basic) rate and 12-24 or 54 Mbps as
supported (optional).
36-54 Mbps can optionally be disabled, if there are not any applications that can benefit from those rates.
Enable CCX Location Measurement.
Cisco Unified IP Phone 9971 Wireless LAN Deployment Guide 48