DOCSIS 3.1 OFDM Channel Configuration
This document describes how to configure the OFDM channel on the Cisco cBR Series Converged Broadband Router.
- Hardware Compatibility Matrix for the Cisco cBR Series Routers
- Information about OFDM Channel Configuration
- How to Configure OFDM Channel
- Configuration Examples
- Additional References
- Feature Information for DOCSIS 3.1 OFDM Channel Configuration
Hardware Compatibility Matrix for the Cisco cBR Series Routers
Note: The hardware components that are introduced in a given Cisco IOS-XE Release are supported in all subsequent releases unless otherwise specified.
| Cisco CMTS Platform | Processor Engine | Interface Cards |
|---|---|---|
| Cisco cBR-8 Converged Broadband Router | Cisco IOS-XE Release 16.5.1 and Later Releases | Cisco IOS-XE Release 16.5.1 and Later Releases |
Cisco cBR-8 Supervisor:
|
Cisco cBR-8 CCAP Line Cards:
|
|
Cisco cBR-8 Downstream PHY Modules:
|
Cisco cBR-8 Upstream PHY Modules:
|
Information about OFDM Channel Configuration
OFDM Channels
DOCSIS 3.1 introduces modes for higher throughput and higher spectral efficiency while still allowing backward compatibility to DOCSIS 3.0. OFDM Channel support includes one OFDM channel per port with channel bandwidth from 24 MHz to 192 MHz wide.
Each OFDM channel supports a control profile, an NCP profile, and up to five data profiles. Profiles support one or more modulations.
Starting from Cisco IOS-XE release 3.18.1SP, you can configure the guard band of an OFDM channel to potentially trade off some performance margin using the command guardband-override. By default, Cisco cBR-8 router uses the default guard band, which is based on the roll off and spacing in the OFDM channel profile.
DOCSIS 3.1 OFDM support also allows the user to configure the RF-channels 158 to 162 under the mac-domain as primary channel.
Channel Profile and Modulation Profile
Channel Profile
A globally configured OFDM channel profile contains channel parameters, and the modulation or modulation profile associated with the control, NCP, and data profiles. Each OFDM channel must specify an OFDM channel profile in its configuration.
Modulation Profile
A globally configured OFDM modulation profile assigns different modulations to ranges of sub-carriers, or lists of individual sub-carriers. A modulation profile may be assigned to a control, NCP, or data profile in a channel profile.
OFDM Channel Exclusion Band
Ranges of frequencies can be excluded from all OFDM channels on a port using the ofdm-freq-excl-band command.
How to Configure OFDM Channel
Configuring OFDM Modulation Profile
To configure the OFDM modulation profile, follow the steps below:
enable
configure terminal
cable downstream ofdm-modulation-profile <id>
description <text>
subcarrier-spacing <value>
width <value>
start-frequency <value>
assign {modulation-default <mod_prof_id> | modulation <mod_prof_id> {list-subcarriers {freq-abs | freq-offset} <value> | range-subcarriers {freq-abs | freq-offset} <value> width <value>}}
Note: Subcarrier spacing must match the subcarrier spacing of each channel profile in which it is configured.
Verifying OFDM Modulation Profile Configuration
To display the OFDM modulation profile details, use the show cable ofdm-modulation-profiles command as shown in the example below:
Router# show cable ofdm-modulation-profile 10 **** OFDM Modulation Profile Configuration **** Prof FFT Width Start-freq Modulations ID KHz Hz Hz 10 50 96000000 627000000 64 default 512 freq-abs 709050000 width 12000000 2048 freq-abs 629000000 width 6000000 Profile Subcarrier Modulations Modulation: Start-freq-abs[start-sc] - End-freq-abs[end-sc] Width-freq[num-sc] 64 : 572600000[ 0] - 626950000[1087] 54400000[1088] 64 : 627000000[1088] - 628950000[1127] 2000000[ 40] 2048: 629000000[1128] - 634950000[1247] 6000000[ 120] 64 : 635000000[1248] - 709000000[2728] 74050000[1481] 512 : 709050000[2729] - 721000000[2968] 12000000[ 240] 64 : 721050000[2969] - 722950000[3007] 1950000[ 39] 64 : 723000000[3008] - 777350000[4095] 54400000[1088] **** OFDM Modulation Profile Assigned Channel Profiles **** Prof Channel ID Profiles 10 30 To display the associations between OFDM modulation profiles and OFDM channel profiles, use the show cable ofdm-modulation-profile command with channel-profiles option as shown in the example below: Router# show cable ofdm-modulation-profile channel-profiles **** OFDM Modulation Profile Assigned Channel Profiles **** Prof Channel ID Profiles 8 None 9 28 10 30 192 192 To display the OFDM modulation profile configurations, use the show cable ofdm-modulation-profile command with configuration option as shown in the example below: Router# show cable ofdm-modulation-profile configuration **** OFDM Modulation Profile Configuration **** Prof FFT Width Start-freq Modulations Description ID KHz Hz Hz (Limited to 20) 8 50 192000000 NA 2048 default 512 freq-off 48000000 width 24000000 9 50 96000000 627000000 512 default 512-1k-4k 1024 freq-abs 635000000 width 74050000 4096 freq-abs 629000000 width 6000000 10 50 96000000 627000000 64 default 512 freq-abs 709050000 width 12000000 2048 freq-abs 629000000 width 6000000
Configuring OFDM Channel Profile
To configure the OFDM channel profile, follow the steps below:
enable
configure terminal
cable downstream ofdm-chan-profile <id>
description <text>
cyclic-prefix <value>
guardband-override <value>
interleaver-depth <value>
pilot-scaling <value>
roll-off <value>
subcarrier-spacing <value>
profile-ncp modulation-default <mod_prof_id>
profile-control {modulation-default <mod_prof_id> | modulation-profile <mod_prof_id>}
profile-data <channel_data_prof_id>{modulation-default <mod_prof_id> |
modulation-profile <mod_prof_id>}
Verifying OFDM Channel Profile Configuration
To display the OFDM channel profile details, use the show cable ofdm-chan-profiles command as shown in the example below:
Router# show cable ofdm-chan-profile 21 **** OFDM Channel Profile Configuration **** Prof Cycl Roll Guardband FFT Intr Pilot Modulation (D-Default, P-Profile) ID Prfx Off Override KHz Depth Scale Cntrl NCP Data Profiles (count = 0) 1 2 3 4 5 21 1024 128 2400000 50 16 48 D:1024 D:16 NA NA NA NA NA **** OFDM Channel Profile Assigned Channels **** Prof Admin Controller:channels ID 21 Up 6/0/4:158 To display the associations between OFDM channel profiles and OFDM channels, use the show cable ofdm-chan-profiles command with channels option as shown in the example below: Router# show cable ofdm-chan-profile channels **** OFDM Channel Profile Assigned Channels **** Prof Admin Controller:channels ID 20 Up 3/0/1:158 30 Up 3/0/6:158 101 Up 3/0/4:158 3/0/2:158 3/0/3:158 3/0/5:158 3/0/7:158
Configuring OFDM Channel as Primary Channel
To configure an RF-channel in the mac-domain as an OFDM primary channel, use the following commands.
enable configure terminal interface cable <slot/subslot/port> downstream Integrated-Cable <slot/subslot/port> rf-channel <ofdm-channel-number: 158-162> end
Verifying OFDM Primary Channel Configuration
To display the OFDM channel configuration details, where the OFDM channel is the primary channel, use the command as shown in the following example:
Router#sh run int c3/0/3 Building configuration... Current configuration : 539 bytes ! interface Cable3/0/3
Configuring Port/Controller and Channel
load-interval 30 downstream Integrated-Cable 3/0/3 rf-channel 0 downstream Integrated-Cable 3/0/3 rf-channel 158 upstream 0 Upstream-Cable 3/0/6 us-channel 0 upstream 1 Upstream-Cable 3/0/6 us-channel 1 upstream 2 Upstream-Cable 3/0/6 us-channel 2 upstream 3 Upstream-Cable 3/0/6 us-channel 3 cable upstream bonding-group 1 upstream 0 upstream 1 upstream 2 upstream 3 attributes 80000000 cable bundle 1 cable cm-status enable 3 6-11 16-18 20-27 cable privacy accept-self-signed-certificate end
You can also use the following command to display the OFDM primary channel configuration details as shown in this example.
Router#sh cable mac-domain c3/0/3 cgd-associations CGD Host Resource DS Channels Upstreams (ALLUS) Active DS Ca3/0/3 3/0/3 0 0-3 Yes 0 158 0-3 Yes 158
The show cable mac-domain Cable <slot>/<subslot>/<port> mdd command also displays the OFDM primary channel configuration details as shown in the example.
Downstream Active Channel List
Channel ID: 159
Frequency: 836000000Hz
Primary Capable: Primary-Capable
CM-STATUS Event Bitmask:0x36
MDD Timeout
QAM FEC failure
MDD Recovery
QAM FEC recovery
MAP/UCD Transport Indicator: Can carry MAPs and UCDs
OFDM PLC Params Bitmask:
Tukey raised cosine window: 0.625
Cyclic Prefix: 5.0
Sub carrier spacing: 50
RF channels use a zero-based numbering scheme, whereas the downstream channel IDs are numbered starting from one. Thus RF channel 158 is equivalent to channel ID 159. The Channel ID in this example is 159. The MAP/UCD Transport Indicator shows that MAPs and UCDs are sent only on Primary Channels.
To configure the port/controller and channel, follow the steps below:
enable configure terminal controller integrated-cable <slot/subslot/port> max-ofdm-spectrum <value> ofdm-freq-excl-band start-frequency <value> width <value> rf-chan <start_id> [<end_id>] ofdm channel-profile <id> start-frequency <value> width <value> [plc <value>]
Verifying Port/Controller and Channel Configuration
Note: The range of start_id is 158 to 162 in the OFDM channel configuration.
The maximum OFDM spectrum is assigned to OFDM channels, which is used by the CMTS to calculate default port base power.
Ranges of frequencies can be excluded from all OFDM channels using the ofdm-freq-excl-band command.
To display the RF port details, use the show controller integrated-cable command with rf-port option as shown in the example below:
Router# show controller integrated-cable 3/0/0 rf-port Admin: UP MaxCarrier: 128 BasePower: 33 dBmV Mode: normal Rf Module 0: UP Free freq block list has 3 blocks: 45000000 - 107999999 624000000 - 644999999 837000000 - 1217999999 Rf Port Status: UP MaxOfdmSpectrum: 192000000 Equivalent 6MHz channels: 32 UsedOfdmSpectrum: 192000000 AvailOfdmSpectrum: 0 DefaultBasePower: 33 dBmV Equivalent 6MHz channels: 160 OFDM frequency exclusion bands: None
To display the summary information on OFDM channel, use the show controller integrated-cable command with rf-channel option as shown in the example below:
Router# show controller integrated-cable 3/0/0 rf-channel 158 Chan State Admin Mod-Type Start Frequency Width PLC Profile-ID dcid power output 158 UP UP OFDM NORMAL 627000000 96000000 663000000 20 159 34
To display detailed information on OFDM channel, use the show controller integrated-cable command with rf-channel and verbose options as shown in the example below:
Router# show controller integrated-cable 3/0/0 rf-channel 158 verbose Chan State Admin Mod-Type Start Frequency Width PLC Profile-ID dcid power output 158 UP UP OFDM NORMAL 627000000 96000000 663000000 30 159 32 Resource status: OK License: granted <17:02:35 EDT May 18 2016> OFDM channel license spectrum width: 92200000 OFDM modulation license (spectrum width): 2K (6000000) OFDM config state: Configured OFDM channel details: [3/0/4:158] ------------------------------------------ OFDM channel frequency/subcarrier range : 627000000[1088] - 722999999[3007] OFDM spectrum frequency/subcarrier range : 572600000[ 0] - 777399999[4095]
Active spectrum frequency/subcarrier range : 628900000[1126] - 721049999[2969]
OFDM channel center frequency/subcarrier : 675000000[2048]
PLC spectrum start frequency/subcarrier : 663000000[1808]
PLC frequency/subcarrier : 665800000[1864]
Channel width : 96000000
Active Channel width : 92200000
OFDM Spectrum width : 204800000
Chan prof id : 30
Cyclic Prefix : 1024
Roll off : 128
Interleave depth : 16
Spacing : 50KHZ
Pilot Scaling : 48
Control modulation profile : 10
NCP modulation default : 16
Data modulation default : 16
Data modulation profile : None
Lower guardband width in freq/subcarriers : None
Upper guardband width in freq/subcarriers : 0
Licensed 4K modulation spectrum width : 6000000
Licensed 2K modulation spectrum width : 0
PLC spectrum frequencies [subcarriers] : 663000000[1808] - 668999999[1927]
PLC channel frequencies [subcarriers] : 665800000[1864] - 666199999[1871] Size: 8 subcarriers
Excluded frequencies [subcarriers] : 721100000[2970] - 777399999[4095]
Count: 2252
Pilot frequencies [subcarriers] :
- *:PLC pilots
630700000[1162] 634300000[1234] 645100000[1450] 648700000[1522] 659500000[1738] 663450000[1817]* 665050000[1849]* 666900000[1886]* 668500000[1918]* 669100000[1930] 679900000[2146] 683500000[2218] 694300000[2434] 697900000[2506] 708700000[2722] 712300000[2794] Count: 32
Active frequencies [subcarriers] : 628900000[1126] - 721099999[2969]
Count: 1844
Data frequencies [subcarriers] :
628900000[1126] - 630699999[1161] 630750000[1163] - 634299999[1233] 634350000[1235] - 637899999[1305] 637950000[1307] - 641499999[1377] 641550000[1379] - 645099999[1449] 645150000[1451] - 648699999[1521] 648750000[1523] - 652299999[1593] 652350000[1595] - 655899999[1665] 655950000[1667] - 659499999[1737] 659550000[1739] - 663449999[1816] 663500000[1818] - 664049999[1828] 664100000[1830] - 664599999[1839] 664650000[1841] - 665049999[1848] 665100000[1850] - 665799999[1863] 666200000[1872] - 666899999[1885] 666950000[1887] - 667349999[1894] 667400000[1896] - 667899999[1905] 667950000[1907] - 668499999[1917] 668550000[1919] - 669099999[1929] 669150000[1931] - 672699999[2001] 672750000[2003] - 676299999[2073] 676350000[2075] - 679899999[2145] 679950000[2147] - 683499999[2217] 683550000[2219] - 687099999[2289] 687150000[2291] - 690699999[2361] 690750000[2363] - 694299999[2433] 694350000[2435] - 697899999[2505] 697950000[2507] - 701499999[2577] 701550000[2579] - 705099999[2649] 705150000[2651] - 708699999[2721]
708750000[2723] - 712299999[2793] 712350000[2795] - 715899999[2865] 715950000[2867] - 719499999[2937] 719550000[2939] - 721099999[2969]
Count: 1804
Profiles:
Number of profiles: 2
CTRL profile (Profile A): rate: 461916 kbps, usable rate: 368000 kbps
Active frequencies [subcarriers]:
Modulation:Start-freq[start-subcarrier] - End-freq[end-subcarrier]
64 :628900000[1126] - 628950000[1127] 2048 :629000000[1128] - 630650000[1161] 2048 :630750000[1163] - 634250000[1233] 2048 :634350000[1235] - 634950000[1247] 64 :635000000[1248] - 637850000[1305] 64 :637950000[1307] - 641450000[1377] 64 :641550000[1379] - 645050000[1449] 64 :645150000[1451] - 648650000[1521] 64 :648750000[1523] - 652250000[1593] 64 :652350000[1595] - 655850000[1665] 64 :655950000[1667] - 659450000[1737] 64 :659550000[1739] - 663400000[1816] 64 :663500000[1818] - 664000000[1828] 64 :664100000[1830] - 664550000[1839] 64 :664650000[1841] - 665000000[1848] 64 :665100000[1850] - 665750000[1863] 64 :666200000[1872] - 666850000[1885] 64 :666950000[1887] - 667300000[1894] 64 :667400000[1896] - 667850000[1905] 64 :667950000[1907] - 668450000[1917] 64 :668550000[1919] - 669050000[1929] 64 :669150000[1931] - 672650000[2001] 64 :672750000[2003] - 676250000[2073] 64 :676350000[2075] - 679850000[2145] 64 :679950000[2147] - 683450000[2217] 64 :683550000[2219] - 687050000[2289] 64 :687150000[2291] - 690650000[2361] 64 :690750000[2363] - 694250000[2433] 64 :694350000[2435] - 697850000[2505] 64 :697950000[2507] - 701450000[2577] 64 :701550000[2579] - 705050000[2649] 64 :705150000[2651] - 708650000[2721]
NCP profile:
Active frequencies [subcarriers]:
Modulation:Start-freq[start-subcarrier] - End-freq[end-subcarrier]
16 :628900000[1126] - 630650000[1161] 16 :630750000[1163] - 634250000[1233] 16 :634350000[1235] - 637850000[1305] 16 :637950000[1307] - 641450000[1377] 16 :641550000[1379] - 645050000[1449] 16 :645150000[1451] - 648650000[1521] 16 :648750000[1523] - 652250000[1593] 16 :652350000[1595] - 655850000[1665] 16 :655950000[1667] - 659450000[1737] 16 :659550000[1739] - 663400000[1816] 16 :663500000[1818] - 664000000[1828] 16 :664100000[1830] - 664550000[1839] 16 :664650000[1841] - 665000000[1848] 16 :665100000[1850] - 665750000[1863] 16 :666200000[1872] - 666850000[1885] 16 :666950000[1887] - 667300000[1894] 16 :667400000[1896] - 667850000[1905] 16 :667950000[1907] - 668450000[1917] 16 :668550000[1919] - 669050000[1929] 16 :669150000[1931] - 672650000[2001] 16 :672750000[2003] - 676250000[2073] 16 :676350000[2075] - 679850000[2145] 16 :679950000[2147] - 683450000[2217] 16 :683550000[2219] - 687050000[2289] 16 :687150000[2291] - 690650000[2361] 16 :690750000[2363] - 694250000[2433] 16 :694350000[2435] - 697850000[2505] 16 :697950000[2507] - 701450000[2577] 16 :701550000[2579] - 705050000[2649] 16 :705150000[2651] - 708650000[2721] 16 :708750000[2723] - 712250000[2793] 16 :712350000[2795] - 715850000[2865] 16 :715950000[2867] - 719450000[2937] 16 :719550000[2939] - 721050000[2969]
Active subcarrier count: 1804, ZBL count: 0
CCCs: OCD CCC: 2 DPD CCCs: Control profile (Profile A) CCC: 2 NCP profile CCC: 2
Resource config time taken: 2286 msecs
JIB channel number: 776
Configuration Examples
This section provides examples for configuring the OFDM channel.
Example1: Configuring OFDM Channel
Note: The OFDM modulation profile must be configured before the OFDM channel profile which references it.
The following example shows how to configure the OFDM channel:
enable configure terminal cable downstream ofdm-modulation-profile 9 description 512-1k-4k subcarrier-spacing 50KHz width 96000000 start-frequency 627000000 assign modulation-default 512-QAM assign modulation 1024-QAM range-subcarriers freq-abs 635000000 width 74050000 assign modulation 4096-QAM range-subcarriers freq-abs 629000000 width 6000000
exit
configure terminal cable downstream ofdm-chan-profile 20 description Data profiles: 2 single mod, 1 mixed mod cyclic-prefix 192 interleaver-depth 16 pilot-scaling 48 roll-off 128 subcarrier-spacing 50KHz profile-ncp modulation-default 16-QAM profile-control modulation-default 256-QAM profile-data 1 modulation-default 1024-QAM profile-data 2 modulation-default 2048-QAM profile-data 3 modulation-profile 9 exit configure terminal controller integrated-cable 3/0/0 max-ofdm-spectrum 96000000 ofdm-freq-excl-band start-frequency 683000000 width 10000000 rf-chan 158 power-adjust 0 docsis-channel-id 159 ofdm channel-profile 20 start-frequency 627000000 width 96000000 plc 663000000
Example 2: Configuring OFDM Primary Channel in the MAC Domain
enable configure terminal Enter configuration commands, one per line. End with CNTL/Z. interface cable 3/0/0 downstream Integrated-Cable 3/0/3 rf-channel 158 end
Additional References
Related Document
| Document Title | Link |
|---|---|
| Cisco cBR Converged Broadband Routers Layer 2 and DOCSIS 3.0 Configuration Guide | http://www.cisco.com/c/en/us/td/docs/cable/cbr/configuration/guide/b_cbr_layer2_docsis30.html |
MIBs
| MIBs | Link |
|---|---|
| DOCS-IF31-MIB To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: | http://www.cisco.com/go/mibs |
Feature Information for DOCSIS 3.1 OFDM Channel Configuration
Technical Assistance
| Description | Link |
|---|---|
| The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. |
http://www.cisco.com/support |
Use Cisco Feature Navigator to find information about the 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 the www.cisco.com/go/cfn link. An account on the Cisco.com page is not required.
Note: The following table lists the software release in which a given feature is introduced. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Table 2: Feature Information for DOCSIS 3.1 OFDM Channel Configuration
| Feature Name | Releases | Feature Information |
|---|---|---|
| DOCSIS 3.1 OFDM Channel Support | Cisco IOS XE Fuji 16.7.1 | This feature was integrated on the Cisco cBR Series Converged Broadband Router s. |
| Full Spectrum 108-1218 MHz Support | Cisco IOS XE Fuji 16.7.1 | This feature was integrated on the Cisco cBR Series Converged Broadband Router s. |
| DOCSIS 3.1 OFDM Primary Channel Support | Cisco IOS XE Fuji 16.7.1 | This feature was integrated on the Cisco cBR Series Converged Broadband Router s. |
| Enhanced support for subcarrier spacing, exclusion band, and LCPR | Cisco IOS XE Fuji 16.7.1 | This feature was integrated on the Cisco cBR Series Converged Broadband Router s. |
Cisco cBR Converged Broadband Routers Layer 2 and DOCSIS 3.0 Configuration Guide - Cisco
