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
Verifying Spectrum Group Configuration Example
To verify if spectrum groups have been configured and activated, enter the show cable spectrum-group
command. This command displays each spectrum group, the frequencies assigned to it, the upstream
port to which it has been assigned, whether a schedule exists for it, the currently measured power level,
and whether it is a shared spectrum group.
CMTS01# show cable spectrum-group
22:07:46: %SYS-5-CONFIG_I: Configured from console by console
Group Frequency Upstream Weekly Scheduled Power Shared
No. Band Port Availability Level Spectrum
(Mhz) From Time: To Time: (dBmV)
1 5.000-15.000 0 Yes
1 12.000 0 Yes
1 22.000 Cable6/0 U5 7 Yes
2 29.000 Cable6/0 U4 6 No
2 26.000 0 No
3 35.000-41.000 0 No
3 16.000-19.000 Cable6/0 U3 5 No
5* 5.000-10.000 Thu 21:50:00 Thu 21:45:00 0 Yes
CMTS01#
Determining the Upstream Ports Assigned to a Combiner Group Example
Following is a sample topology for a CMTS with combiner groups designated A through J. Combiner
groups C and E have multiple upstream ports that should be configured in a shared spectrum group. The
other upstreams should be configured in a nonshared spectrum group.
In this example, ten combiner groups are served with frequency hop tables from three spectrum groups:
Cable3/0
DS +-----+ Upconverter +----- laser group 1
U0 +----- combiner group A
U1 +----- combiner group B
U2 +------combiner group C
U3 +------combiner group C
U4 +----- combiner group D
U5 +------combiner group E
Cable4/0
DS +-----+ Upconverter +----- laser group 2
U0 +------combiner group E
U1 +----- combiner group F
U2 +----- combiner group G
U3 +----- combiner group H
U4 +----- combiner group I
U5 +----- combiner group J
The laser group term refers to the set of fiber nodes that share the same downstream signal. An optical
splitter is often used to create individual feeds per node.
In the downstream direction, two 6-MHz channel slots are assigned. All fiber nodes in combiner groups
A through E should have a channel slot containing the downstream signal from Cable3/0. Combiner
groups A through E are said to belong to laser group 1.
All fiber nodes in combiner groups E through J should have a channel slot containing the downstream
signal from Cable4/0. Combiner groups E through J are said to belong to laser group 2.
Because combiner group E belongs to two laser groups, there should be two different downstream
channel slots for Cable3/0 and Cable4/0.