Cisco Systems OL-6415-04 manual Enabling and Disabling Short Radio Preambles

Chapter 2 Configuring Radio Settings

Enabling and Disabling Short Radio Preambles

Beginning in privileged EXEC mode, follow these steps to enable world mode:

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	interface dot11radio { 0 1}	Enter interface configuration mode for the radio interface.
Step 3
	world-mode	Enable world mode.
	dot11d country_code code	• Enter the dot11d option to enable 802.11d world mode.
	{ both indoor outdoor }
		– When you enter the dot11d option, you must enter a
	legacy
		two-character ISO country code (for example, the ISO
		country code for the United States is US). You can find
		a list of ISO country codes at the ISO website.
		– After the country code, you must enter indoor,
		outdoor, or both to indicate the placement of the
		wireless device.
		• Enter the legacy option to enable Cisco legacy world
		mode.
		Note Access Point extensions must be enabled for legacy
		world mode operation, but Access Point extensions are
		not required for 802.11d world mode. Access Point
		extensions are enabled by default.
Step 4
	end	Return to privileged EXEC mode.
Step 5
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

Use the no form of the command to disable world mode.

Enabling and Disabling Short Radio Preambles

The radio preamble (sometimes called a header) is a section of data at the head of a packet that contains information that the wireless device and client devices need when sending and receiving packets. You can set the radio preamble to long or short:

•Short—A short preamble improves throughput performance. Cisco Access Point Wireless LAN Client Adapters support short preambles.

•Long—A long preamble ensures compatibility between the wireless device and all early models of Cisco Access Point Wireless LAN Adapters (PC4800 and PC4800A). If these client devices do not associate to the wireless devices, you should use short preambles.

You cannot configure short or long radio preambles on the 5-GHz radio.

Beginning in privileged EXEC mode, follow these steps to disable short radio preambles:

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	interface dot11radio { 0 }	Enter interface configuration mode for the 2.4-GHz radio
		interface.
		Cisco Wireless ISR and HWIC Access Point Configuration Guide
OL-6415-04			2-21