Juniper Networks G10 CMTS manual Radio Frequency RF Specifications

Radio Frequency (RF) Specifications

•Table 47: Downstream RF Channel Transmission Characteristics

•	Parameter	Value
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	Frequency range	Cable system normal downstream operating range is from 50 MHz to as
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		high as 860 MHz. However, the values in this table apply only at frequencies
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		>= 88 MHz.
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	RF channel spacing (design bandwidth)	6 MHz
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	Transit delay from headend to most distant customer	<= 0.800 msec (typically much less)
•
•	Carrier-to-noise ratio in a 6-MHz band (analog video level)	Not less than 35 dB4
•	Carrier-to-interference ratio for total power (discrete and broadband ingress	Not less than 35 dB within the design bandwidth

•signals)

•	Composite triple beat distortion for analog modulated carriers	Not greater than -50 dBc within the design bandwidth
•
	Composite second order distortion for analog odulated carriers	Not greater than -50 dBc within the design bandwidth
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•	Cross-modulation level	Not greater than -40 dBc within the design bandwidth
•	Amplitude ripple	0.5 dB within the design bandwidth
•
	Group delay ripple in the spectrum occupied by the CMTS	75 ns within the design bandwidth
•
	Micro-reflections bound for dominant echo	-10 dBc @ <= 0.5 m sec, -15 dBc @ <= 1.0 m sec
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		-20 dBc @ <= 1.5 m sec, -30 dBc @ > 1.5 m sec
•
	Carrier hum modulation	Not greater than -26 dBc (5%)
•
•	Burst noise	Not longer than 25 m sec at a 10 Hz average rate
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	Seasonal and diurnal signal level variation	8 dB
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	Signal level slope, 50-750 MHz	16 dB
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•	Maximum analog video carrier level at the CM input, inclusive of above	17 dBmV

•signal level variation

• Lowest analog video carrier level at the CM input, inclusive of above signal -5 dBmV

•level variation

•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 highest-frequency NTSC carrier level.

•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 carrier level, this C/N may be less.

•5. Measurement methods defined in [NCTA] or [CableLabs2].

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176 JUNOSg 3.0 G10 CMTS Hardware Guide