Table 47: Downstream Rf Channel Transmission Characteristics - Juniper G10 CMTS Hardware Manual

Radio Frequency (RF) Specifications
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Table 47: Downstream RF Channel Transmission Characteristics

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Parameter
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Frequency range
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RF channel spacing (design bandwidth)
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Transit delay from headend to most distant customer
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• Carrier-to-noise ratio in a 6-MHz band (analog video level)
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Carrier-to-interference ratio for total power (discrete and broadband ingress
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signals)
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Composite triple beat distortion for analog modulated carriers
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Composite second order distortion for analog odulated carriers
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Cross-modulation level
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Amplitude ripple
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Group delay ripple in the spectrum occupied by the CMTS
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Micro-reflections bound for dominant echo
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Carrier hum modulation
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Burst noise
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Seasonal and diurnal signal level variation
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Signal level slope, 50-750 MHz
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Maximum analog video carrier level at the CM input, inclusive of above
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signal level variation
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• Lowest analog video carrier level at the CM input, inclusive of above signal
level variation
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1. Transmission is from the headend combiner to the CM input at the customer location.
2. For measurements above the normal downstream operating frequency band (except hum), impairments are referenced to the
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highest-frequency NTSC carrier level.
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3. For hum measurements above the normal downstream operating frequency band, a continuous-wave carrier is sent at the test frequency
• at the same level as the highest-frequency NTSC carrier.
4. This presumes that the digital carrier is operated at analog peak carrier level. When the digital carrier is operated below the analog peak
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carrier level, this C/N may be less.
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5. Measurement methods defined in [NCTA] or [CableLabs2].
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176 JUNOSg 3.0 G10 CMTS Hardware Guide
Value
Cable system normal downstream operating range is from 50 MHz to as
high as 860 MHz. However, the values in this table apply only at frequencies
>= 88 MHz.
6 MHz
<= 0.800 msec (typically much less)
4
Not less than 35 dB
Not less than 35 dB within the design bandwidth
Not greater than -50 dBc within the design bandwidth
Not greater than -50 dBc within the design bandwidth
Not greater than -40 dBc within the design bandwidth
0.5 dB within the design bandwidth
75 ns within the design bandwidth
-10 dBc @ <= 0.5 m sec, -15 dBc @ <= 1.0 m sec
-20 dBc @ <= 1.5 m sec, -30 dBc @ > 1.5 m sec
Not greater than -26 dBc (5%)
Not longer than 25 m sec at a 10 Hz average rate
8 dB
16 dB
17 dBmV
-5 dBmV