Specifications

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Cisco Cable Modem Termination System Feature Guide

0L-1467-02

Chapter 3 Spectrum Management for the Cisco Cable Modem Termination System

Related Documents

• For Intelligent and Advanced spectrum management features (hardware-based, CNR frequency

hopping), Cisco uBR-MC16S cable interface line card (Cisco uBR7200 series routers) or

Cisco uBR-LCP2-MC16S cable interface line card (Cisco uBR10012 routers).

• Ensure that your network is designed to support reliable broadband data transmission. At minimum,

your network must include:

–

A Dynamic Host Configuration Protocol (DHCP) server to assign IP addresses to cable modems

or set-top boxes on the hybrid fiber-coaxial (HFC) network. This can be a server on the WAN

side of the Cisco uBR7200 series router or a Cisco CMTS router that has been configured to act

as the DHCP server.

–

If you are not using the Cisco uBR7100 series router with integrated upconverter, you must

install the appropriate IF-to-RF external upconverter between the Cisco CMTS router and the

combiner.

Note The term “combiner” refers to all cables, amplifiers, and taps at the headend or cable

distribution center that connect the Cisco CMTS router to the HFC network.

–

Diplex filters installed in the downstream RF path between the cable modems and the cable

interface cards in the router. RG-59 headend coaxial cable with the maximum braid available

(60 percent + 40 percent braid), double foil, and the correct connector for this cable.

• Avoid frequencies with known ingress problems such as amateur radio bands or short-wave bands.

• Avoid hostile spectrums below 20 MHz.

• When designing your channel plan, allow extra bands for frequency hopping.

• Place upstream ports in the same combiner group in a shared spectrum group.

• Use the receive power level setting to perform slight equalization adjustments.

• Due to the nature of CATV technology, upstream noise management is a significant issue.

Cisco recommends that you follow the rigorous North American plant maintenance procedures that

are documented in the NCTA Supplement on Upstream Transport Issues to adjust return amplifiers

and lasers.