Pengo Computer Accessories UBR7200 manual Configuring the Automatic Level Control ALC

Multipoint Wireless Support for the Cisco uBR7200 Series Universal Broadband Router

Configuration Tasks

Upstream Channel

	Command	Purpose
Step 1
	Router(config)# radio upstream frequency freq width	Sets the upstream frequency and bandwidth.
	width
		Note	The width parameter specifies the
			bandwith for the upstream channel group
			(the basic hardware channel). The freq
			parameter specifies the center frequency
			for this group of upstream channels. For
			example, the only basic channel width that
			is supported by the initial hardware
			release is 6.0 MHz.
Step 2
	Router(config-if)#radio upstream usportnum subchannel	Sets the subchannel and modulation-profile
	sn modulation-profile p	assignment for the upstream channel.
		Note	The bandwidth of the subchannel must
			match the bandwidth of the
			modulation-profile.
Step 3
	Router(config)# radio transmit-power power-level	Sets the downstream transmit power to power in
		dBm.
Step 4
	Router(config-if)# radio upstream usportnum	Sets the target receive power in dBm for the
	target-receive-power power-level	upstream port. The usportnum field specifies the
		upstream port number. The target receive power
		must be set for each upstream port.
Step 5
	Router(config-if)#radio upstream usportnum shutdown	Shuts down the upstream channel.

Configuring the Automatic Level Control (ALC)

The automatic level control (ALC) module governs the individual transmit power levels of all the subscriber units. The purpose of ALC is to ensure that the target receive power at the headend is maintained over time by taking power measurements of all the subscribers many times per second. Taking power measurements in small intervals results in better resilience to the fading environment, but it consumes more upstream bandwidth. ALC can be disabled, but this is not recommended because it results in poor upstream link performance. The current system allows only one interval setting for an entire sector. The default interval is 96 ms.

	Command	Purpose
Step 1
	Router# configure terminal	Enables the global interface configuration mode.
Step 2
	Router(config)# interface radio slot/port	Specifies the line card to be configured. In this
		example, the line card installed in a specific
		slot/port number.
Step 3
	Router(config-if)# radio alc interval interval	Configures the ALC interval for the sector at a
		specified interval value.
		Cisco IOS Release 12.1(5)XM

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