Configuring Headend Broadband Access Router Features
Configuring and Activating Frequency Agility
•Configuring Spectrum Group Characteristics
•Assigning the Spectrum Group and the Upstream Ports
Determining the Upstream Ports Assigned to a Combiner Group
Following is an example topology for a Cisco uBR7223 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 |
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DS | + Upconverter | laser group 1 | |
U0 | combiner group A |
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U1 | combiner group B |
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U2 | combiner group C |
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U3 | combiner group C |
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U4 | combiner group D |
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U5 | combiner group E |
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Cable4/0 |
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DS | + Upconverter | laser group 2 | |
U0 | combiner group E |
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U1 | combiner group F |
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U2 | combiner group G |
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U3 | combiner group H |
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U4 | combiner group I |
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U5 | combiner group J |
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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.
Cisco IOS Multiservice Applications Configuration Guide
