Specifications

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Cisco Cable Modem Termination System Feature Guide
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Chapter 3 Spectrum Management for the Cisco Cable Modem Termination System
Configuration Examples
Combiner Group Example
The following example enables spectrum management for all upstream ports, where 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 Cable3/0
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)# cable upstream 5 spectrum-group 3
CMTS01(config-if)# exit
CMTS01(config)# interface Cable4/0
CMTS01(config-if)# cable spectrum-group 1
CMTS01(config-if)# cable upstream 0 spectrum-group 3
A description of the spectrum groups 1 through 3 follows:
• Spectrum group 1—This group is nonshared. Upstream RF domains exist for each member upstream
port.
Upstream Port RF Domain
Cable3/0 U0 combiner group A
Cable3/0 U1 combiner group B
Cable3/0 U4 combiner group D
Cable4/0 U1 combiner group F
Cable4/0 U2 combiner group G
Cable4/0 U3 combiner group H
Cable4/0 U4 combiner group I
Cable4/0 U5 combiner group J
• Spectrum group 2—This group is shared. A single upstream RF domain exists.
Upstream Port RF Domain
Cable3/0 U2 combiner group C
Cable3/0 U3 combiner group C
• Spectrum group 3—This group is shared. A single upstream RF domain exists.
Upstream Port RF Domain
Cable3/0 U5 combiner group E
Cable4/0 U0 combiner group E
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 Cable3/0 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.