Juniper Networks G10 CMTS manual Downstream RF Signal Output Characteristics

Radio Frequency (RF) Specifications

•Table 49: Downstream RF Signal Output Characteristics

•	Parameter	Value
•
	Center Frequency (fc)	91 to 857 MHz ± 30 kHz1
•
	Level	Adjustable over the range 50 to 61 dBmV
•

•Symbol Rate (nominal)

•	64QAM	5.056941 Msym/sec
•	256QAM	5.360537 Msym/sec
•	Nominal Channel Spacing	6 MHz

•Frequency response

•	64QAM	~18% Square Root Raised Cosine shaping
•	256QAM	~12% Square Root Raised Cosine shaping
•	Total Discrete Spurious Inband (fc ± 3 MHz)	< -57dBc
•
•	Inband Spurious and Noise (fc ± 3 MHz)	< -48dBc; where channel spurious and noise includes all discrete spurious,
•
		noise, carrier leakage, clock lines, synthesizer products, and other undesired
•
		transmitter products. Noise within +/- 50kHz of the carrier is excluded.
•
•	Adjacent channel (fc ± 3.0 MHz) to (fc ± 3.75 MHz)	< -58 dBc in 750 kHz
•
•
•	Adjacent channel (fc ± 3.75 MHz) to (fc ± 9 MHz)	< -62 dBc, in 5.25 MHz, excluding up to 3 spurs, each of which must be
•		<-60 dBc when measured in a 10 kHz band
•
•	Next adjacent channel (fc ± 9 MHz) to (fc ± 15 MHz)	Less than the greater of -65 dBc or -12dBmV in 6MHz, excluding up to three
•		discrete spurs. The total power in the spurs must be < -60dBc when each is
•		measured with 10 kHz bandwidth.
•
•	Other channels (47 MHz to 1,000 MHz)	< -12dBmV in each 6 MHz channel, excluding up to three discrete spurs. The
•		total power in the spurs must be < -60dBc when each is measured with
•		10kHz bandwidth.
•	Phase Noise	1 kHz - 10 kHz: -33dBc double sided noise power
•		10 kHz - 50 kHz: -51dBc double sided noise power
•		50 kHz - 3 MHz: -51dBc double sided noise power
•
	Output Impedance	75 ohms
•
•	Output Return Loss	> 14 dB within an output channel up to 750 MHz;
•		> 13 dB in an output channel above 750 MHz
•	Connector	F connector per [IPS-SP-406]

•1. ±30 kHz includes an allowance of 25 kHz for the largest FCC frequency offset normally built into upconverters.

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•Table 50: DOCSIS Downstream Channel Rates and Spacing

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	Nominal Symbol Rate	Nominal Channel Spacing
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	(Msym/sec)	(kHz)	Bit Rate (bps)
•
	5.056941 (64QAM)	6000	30,341,646
•
•	5.360537 (256QAM)	6000	42,884,296

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178 JUNOSg 3.0 G10 CMTS Hardware Guide