Pilot tone is a continuous wave signal that is generated and placed in the appropriate portion of the downstream spectrum
in the HFC network.
Pilot Tone Use Cases
Pilot Tones can be used:
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For AGC Amplifier
-
Power: +3 ~ +9 dB relative to the 256-QAM level
-
Frequency: Minimum Frequency: 54–550 MHz, Recommended Frequency: 54–1218 MHz
-
Number Required: 3
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As Alignment tone
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Power: -3 ~ +3 dB relative to the 256-QAM level
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Frequency: Minimum Frequency: 54–550 MHz, Recommended Frequency: 54–1218 MHz
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Number Required: 2
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As Legacy leakage detection signal
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As Next Gen leakage detection signal
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Power: -36 ~ -18 dB relative to the 256-QAM level
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Frequency: Recomended Frequency: 136.750/138/612/774 M Hz
-
Number Required: 2 ( 2*2 carriers)
How to Use Pilot Tones
Dedicated tones have better power level and frequency accuracy than SC-QAM based tones.
RPD Pilot Tone Capabilities
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NumCwToneGens: 4
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LowestCwToneFreq:50000000
-
HighestCwToneFreq: 1218000000
-
MaxPowerDedCwTone: +12.7 dB
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QamAsPilot: 1
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MinPowerDedCwTone: -36.0 dB
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MaxPowerQamCwTone: +12.7 dB
-
MinPowerQamCwTone: -6.0 dB
Use the following command to show RPD pilot tone capabilities
router#show cable rpd badb.ad13.411c capability
......
RPD ID : badb.ad13.411c
......
Number of CW Tone Generators : 4
Lowest CW Tone Frequency : 50000000
Highest CW Tone Frequency : 1218000000
MAX Power of Dedicated CW Tone : 12.7 dB
QAM as Pilot setting : 1
MIN Power of Dedicated CW Tone : -36.0 dB
MAX Power of QAM CW Tone : 12.7 dB
MIN Power of QAM CW Tone : -6.0 dB
......
Configure and Verify Pilot Tone Profile Configuration
Use the cable downstream-pilot-tone profile profile-id command to configure Pilot Tone Profiles. Here is a sample configuration:
router(config)# cable downstream-pilot-tone profile 1
router(config-ds-pilot-tone-prof)# rf-chan 35
router(config-rf-chan)# frequency 267000000
router(config-dedi-tone)# power-adjust 1.0
router(config-rf-chan)# no mute
router(config-rf-chan)# dedicated-tone 0
router(config-dedi-tone)# frequency 400000000
router(config-dedi-tone)# freq-frac 10
router(config-dedi-tone)# power-adjust 12.0
router(config-dedi-tone)# no mute
Use the show cable downstream-pilot-tone profile profile-id command to verify Pilot Tone Profile configuration. Here is a sample configuration:
router# show cable downstream-pilot-tone profile 1
Load for five secs: 4%/2%; one minute: 5%; five minutes: 5%
Time source is NTP, 11:21:57.707 CST Mon May 15 2017
Downstream pilot tone profile 1:
Reference counter: 0
SC-QAM as tone list:
rf-chan-id freq pwr_adj mute
35 267000000 1.0 N
Dedicated tone list:
dedicated-tone freq freq_frac pwr_adj mute
0 400000000 10 12.0 N
You can also view the pilot tone profile configuration from the running configuration. Here is a sample configuration:
router# show running-config | beg cable downstream-pilot-tone profile 1
cable downstream-pilot-tone profile 1
rf-chan 35
frequency 267000000
power-adjust 1.0
no mute
dedicated-tone 0
frequency 400000000
freq_-frac 10
power-adjust 12.0
no mute
Use the following command to show pilot tone status:
router# show cable rpd 0004.9f00.0719 pilot-tone
Load for five secs: 8%/1%; one minute: 9%; five minutes: 9%
No time source, *06:03:44.969 CST Wed Mar 29 2017
Downstream 0 pilot tone profile 1:
SC-QAM as tone list:
rf-chan-id freq pwr_adj mute
35 267000000 0.0 N
Dedicated tone list:
dedicated-tone freq freq_frac pwr_adj mute
0 400000000 10 12.0 N
Use the following command to show pilot tones on an RPD:
R-PHY# show downstream calibreation info
Configuration details:
QAM channel count : 21
OFDM channel count : 1
Number of OOB channels : 0
Number of SC-QAM based tones : 2
Number of leakage tones : 1
Number of allignment tones : 3
SC-QAM based Pilot Tones:
[145, on] 350123456 Hz, 15.0 -> 15.0 dBmv {scale=2227}
[146, on] 360000000 Hz, 33.7 -> 33.7 dBmv {sca1e=19381}
Allignment Tones:
[ 0, on] 385654321.8 Hz 6.0dB {OFDM scaler=43948, sine scaler=14094}
[ 1, on] 395000000.0 Hz 3.0dB {OFDM scaler=43948, sine scaler=10036}
[ 3, on] 411000000.0 Hz -3.0dB {OFDM scaler=43948, sine scaler=5006}
Leakage detection Tones:
[ 2, on] 400000000.0 Hz 9.0dB {OFDM scaler=43948, sine scaler=158}
Bind Pilot Tone Profiles to RPDs
Use the following command to bind a pilot tone profile to an RPD:
router(config)#cable rpd p1_0719
router(config-rpd)#rpd-ds 0 downstream-pilot-tone profile 1
Use the following command to unbind a pilot tone profile to an RPD:
router(config)#cable rpd p1_0719
router(config-rpd)#no rpd-ds 0 downstream-pilot-tone profile 1
Use the following command to show pilot tone binding configuration from RPD configuration:
router #show running | beg cable rpd p1_0719
cable rpd p1_0719
identifier 0004.9f00.0719
rpd-ds 0 downstream-pilot-tone profile 1
core-interface Te6/1/0
principal
rpd-ds 0 downstream-cable 6/0/0 profile 7
rpd-us 0 upstream-cable 6/0/0 profile 7
r-dti 1
rpd-event profile 0
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