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This document describes how to configure the QAM profile on the Cisco cBR Series Converged Broadband Router.
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/. An account on http://www.cisco.com/ is not required.
A QAM profile describes the common downstream channel modulator settings, referred to as physical layer parameters. This includes QAM constellation, symbol rate, interleaver-depth, spectrum-inversion, and annex.
The QAM profile is described by CCAP DownPhyParams object. Default QAM profiles are supported and customized for DOCSIS or MPEG Video, which are described as DocsisPhyDefault and VideoPhyDefault objects, respectively.
A maximum of 32 QAM profiles can be defined. There are four system-defined QAM profiles (0 to 3), which cannot be deleted or modified. You can define profiles 4 to 31.
The system defined profiles are:
Profile 0 - default-annex-b-64-qam
interleaver-depth: I32-J4
symbol rate: 5057 kilo-symbol/second
spectrum-inversion: off
Profile 1 - default-annex-b-256-qam
interleaver-depth: I32-J4
symbol rate: 5361 kilo-symbol/second
spectrum-inversion: off
Profile 2 - default-annex-a-64-qam
interleaver-depth: I12-J17
symbol rate: 6952 kilo-symbol/second
spectrum-inversion: off
Profile 3 - default-annex-a-256-qam
interleaver-depth: I12-J17
symbol rate: 6952 kilo-symbol/second
spectrum-inversion: off
Note | To know more about the commands referenced in this section, see the Cisco IOS Master Command List. |
Enable configure terminal cabledownstream qam-profile Qam_Profile_ID D annex {A | B | C} description LINE interleaver-depth {I12-J17 | I128-J1 | I128-J2 | I128-J3 | I128-J4 | I128-J5 | I128-J6 | I128-J7 | I128-J8 | I16-J8 | I32-J4 | I64-J2 | I8-J16} modulation {256 | 64} spectrum-inversion {off | on} symbol-rate value exit
You can configure symbol rate for Annex A video and Annex C video. The valid range for Annex A video is 3500 to 7000 kilo-symbols/sec. The valid range for Annex C video is 3500 to 5309 kilo-symbols/sec. The channel width in kHz is symbol-rate * (1 + alpha) with 0.15 alpha for Annex A and 0.13 alpha for Annex C.
Use the following commands to verify the QAM Profile on Downstream Channels:
Router#show running-config | section downstream controller-profile cable downstream controller-profile 0 rf-chan 0 3 type DOCSIS frequency 111000000 rf-output NORMAL qam-profile 1 docsis-channel-id 1
configure terminal cable downstream controller-profile 1 multicast-pool 20 Rf-channel 0 15 Type docsis Frequency 111000000 Rf-output NORMAL Qam-profile 1 Docsis-channel-id 1 cable downstream controller-profile 2 multicast-pool 20 Rf-channel 20 47 Type video sync Frequency 231000000 Rf-output NORMAL Qam-profile 14
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note | The table below lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature. |
Feature Name |
Releases |
Feature Information |
---|---|---|
QAM Profile Configuration-RPHY Annex B |
Cisco 1x2 / Compact Shelf RPD Software 1.1 |
This feature was introduced on the Cisco Remote PHY Device. |
QAM Profile Configuration-RPHY Annex A and C |
Cisco 1x2 / Compact Shelf RPD Software 3.1 |
This feature was introduced on the Cisco Remote PHY Device. |