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Table 49, Downstream rf signal output characteristics, Table 50 – Juniper Networks G10 CMTS User Manual

Page 194: Docsis downstream channel rates and spacing

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Radio Frequency (RF) Specifications


























































JUNOSg 3.0 G10 CMTS Hardware Guide

178

Table 49: Downstream RF Signal Output Characteristics

Table 50: DOCSIS Downstream Channel Rates and Spacing

Parameter

Value

Center Frequency (fc)

91 to 857 MHz ± 30 kHz

1

Level

Adjustable over the range 50 to 61 dBmV

Symbol Rate (nominal)
64QAM
256QAM

5.056941 Msym/sec
5.360537 Msym/sec

Nominal Channel Spacing

6 MHz

Frequency response
64QAM
256QAM

~18% Square Root Raised Cosine shaping
~12% Square Root Raised Cosine shaping

Total Discrete Spurious Inband (fc ± 3 MHz)

Inband Spurious and Noise (fc ± 3 MHz)

Adjacent channel (fc ± 3.0 MHz) to (fc ± 3.75 MHz)

Adjacent channel (fc ± 3.75 MHz) to (fc ± 9 MHz)

Next adjacent channel (fc ± 9 MHz) to (fc ± 15 MHz)

Other channels (47 MHz to 1,000 MHz)

< -57dBc

< -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.

< -58 dBc in 750 kHz

< -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

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.

< -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.

Nominal Symbol Rate
(Msym/sec)

Nominal Channel Spacing
(kHz)

Bit Rate (bps)

5.056941 (64QAM)

6000

30,341,646

5.360537 (256QAM)

6000

42,884,296