DOCSIS 3.1 Commanded Power for Upstream SC-QAMs

This guide describes commanded power for upstream SC-QAMs on the Cisco cBR Router.

Hardware Compatibility Matrix for Cisco cBR Series Routers


Note

The hardware components introduced in a given Cisco IOS-XE Release are supported in all subsequent releases unless otherwise specified.


Table 1. Hardware Compatibility Matrix for the Cisco cBR Series Routers

Cisco CMTS Platform

Processor Engine

Interface Cards

Cisco cBR-8 Converged Broadband Router

Cisco IOS-XE Release 3.15.0S and Later Releases

Cisco cBR-8 Supervisor :

  • PID—CBR-CCAP-SUP-160G

  • PID—CBR-CCAP-SUP-60G1

  • PID—CBR-SUP-8X10G-PIC

Cisco IOS-XE Release 3.15.0S and Later Releases

Cisco cBR-8 CCAP Line Cards:

  • PID—CBR-LC-8D30-16U30

  • PID—CBR-LC-8D31-16U30

  • PID—CBR-RF-PIC

  • PID—CBR-RF-PROT-PIC

Cisco cBR-8 Downstream PHY Modules:

  • PID—CBR-D30-DS-MOD

  • PID—CBR-D31-DS-MOD

Cisco cBR-8 Upstream PHY Modules:

  • PID—CBR-D30-US-MOD

1 Effective with Cisco IOS-XE Release 3.17.0S, CBR-CCAP-SUP-60G supports 8 cable line cards. The total traffic rate is limited to 60Gbps, the total number of downstream service flow is limited to 72268, and downstream unicast low-latency flow does not count against the limits.

Information About Commanded Power Feature for Upstream SC-QAMs

Commanded Power feature for UpStream Single Carrier Quadrature Amplitude Modulation (US SC-QAMs), introduced in Cisco IOS-XE Release 3.18.0SP, supports a new method during ranging to dynamically set the transmit power level of a DOCSIS 3.1 cable modem.

To view the new commanded power levels pr upstream, use the following command:
Router# show cable modem [ ip-address | mac-address | cable {slot /subslot /cable-interface-index}] verbose

Note

DOCSIS 3.1 Commanded Power feature is enabled by default.


Feature TLVs

TLVs Affected by Commanded Power for US SC-QAMs

The following table lists the TLVs affected by the DOCSIS 3.1 Ranging Response (RNG-RSP) Commanded Power for upstream SC-QAMs:

Name

Type

DOCSIS 3.1 Value

Power Level Adjust

2

TX Power offset adjustment (signed 8-bit, 1/4-dB units)

Power Offset

12.4.4

TX Power offset adjustment (signed 8-bit, 1/4-dB units)

Dynamic Range Window Upper Edge

14

The upper edge of the Dynamic Range Window expressed in units 1/4 dB below the max allowable setting (Phi) [DOCSIS PHYv3.0].

Commanded Power

17

This TLV contains the Dynamic Range Window value, P1.6load_min_set as well as the Transmit Power Level for each of the channels in the CM's Transmit Channel Set, expressed in units of quarter dBmV.

Commanded Power Sub-TLVs

The following table lists the sub-TLVs for DOCSIS 3.1 Commanded Power:

Name

Type (1 byte)

Length (1 byte)

Value (Variable Length)

Commanded Power

17

5 + 3*N

Dynamic Range Window

17.1

1

The range, in decibels, of the maximum difference in power per 1.6 MHz between multiple transmitters in a cable modem’s Transmit Channel Set.

List of Upstream Channel IDs and Corresponding Transmit Power Levels

17.2

3*N

Values for each channel in the TCS:

  • Bits 23 to 16: UCID

  • Bits 15 to 0: Transmit Power Level (quarter dBmV)

Feature Information for Commanded Power for US SC-QAMs

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://tools.cisco.com/ITDIT/CFN/. An account on http://www.cisco.com/ is not required.


Note

The below table 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.


Table 2. Feature Information for Commanded Power Feature

Feature Name

Releases

Feature Information

DOCSIS 3.1 Commanded Power for US SC-QAMs

Cisco IOS-XE Release 3.18.0SP

This feature was introduced on the Cisco cBR Series Converged Broadband Routers.

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