Installation guide

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Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
OL-2238-03
Chapter 3 Configuring the Cisco Cable Interface
Configuring and Activating Frequency Agility
Tip You must repeat one of the previous command for each frequency or power level that you want to add to
a spectrum group’s list of valid values.
If your cable plant has an upstream noise characteristic on a weekly cycle, use time-scheduled spectrum
allocation:
CMTS01(config)# cable spectrum-group 1 time Mon 08:00:00 frequency 21600000
Deletion is performed using the delete keyword:
CMTS01(config)# cable spectrum-group 1 time Mon 18:00:00 delete frequency 21600000
The following example displays a spectrum group configuration that is designed to perform minor
equalization as a function of frequency.
CMTS01(config)# cable spectrum-group 1 frequency 21600000
CMTS01(config)# cable spectrum-group 1 frequency 24800000 1
CMTS01(config)# cable spectrum-group 1 frequency 28000000 2
In the previous example, the upstream port nominal receive power at 21.6 MHz is 0 dBmV, at 24.8 MHz
is 1 dBmV, and at 28.0 MHz is 2 dBmV. At any time, the power level set in the interface configuration
overrides the spectrum group power level.
The following example enables spectrum management for all upstream ports, assuming that all combiner
groups use the frequency band from 20 to 26 MHz:
CMTS01(config)# cable spectrum-group 1 band 20000000 26000000
CMTS01(config)# cable spectrum-group 2 shared
CMTS01(config)# cable spectrum-group 2 band 20000000 26000000
CMTS01(config)# cable spectrum-group 3 shared
CMTS01(config)# cable spectrum-group 3 band 20000000 26000000
CMTS01(config)# interface Cable1/0
CMTS01(config-if)# cable spectrum-group 1
CMTS01(config-if)# cable upstream 2 spectrum-group 2
CMTS01(config-if)# cable upstream 3 spectrum-group 2
CMTS01(config-if)# exit
For the 20 to 26 MHz band of each RF domain, the spectrum is channelized according to the
channel width settings of each member port. For example, if the ports U2 and U3 of Cable1/0 are set to
3.2 MHz and 1.6 MHz channel widths, respectively, then spectrum group 2 uses the following
channelization:
> Channel Width Start Stop Center
> (Mhz) (Mhz) (Mhz) (Mhz)
> 1 3.2 20.0 23.2 21.6
> 2* 1.6 20.0 21.6 20.8
> 3* 1.6 21.6 23.2 22.4
> 4 1.6 23.2 24.8 24.0
Note Channels 2 and 3 are not available when channel 1 is in use.
Because the group is shared, ports U2 and U3 will be assigned channels 1 and 4, respectively, to prevent
overlap.
Note There are no alternate frequency assignments for either port and bandwidth is wasted from 24.8 to
26.0 MHz. To create alternate channels, increase the upper boundary from 26.0 to 28.0 MHz.