Cisco uBR7100 Series Hardware Installation Manual page 98
Ubr7100, ubr7100e series universal broadband router
Hide thumbs
Also See for uBR7100 Series:
- Hardware installation manual (138 pages) ,
- Quick reference manual (38 pages)
Table of Contents
Advertisement
DOCSIS Upstream and Downstream Specifications
Table A-5
DOCSIS Cable Upstream RF Specifications (continued)
Specification
Seasonal/diurnal signal level
variation
Carrier to second order
Digital Signal Levels
From cable modem (upstream)
Input amplitude to modem card
(upstream)
Signal as relative to adjacent video
signal
1. DOCSIS specifications are baseline settings for a DOCSIS-compliant, two-way data-over-cable system.
2. Minimum settings are slightly different than the DOCSIS settings to account for cable system variations over time and temperature. Using these settings
should increase the reliability of DOCSIS-compliant, two-way data-over-cable systems.
3. QPSK = Quadrature Phase-Shift Keying: a method of modulating digital signals onto a radio-frequency carrier signal using four phase states to code
two digital bits.
4. These settings are measured relative to the digital carrier. Add 6 or 10 dB, as determined by your company's policy and derived from the initial cable
network setup, relative to the analog video signal.
5. QAM = Quadrature Amplitude Modulation: a method of modulating digital signals onto a radio-frequency carrier signal involving both amplitude and
phase coding.
6. dBc = decibels relative to carrier.
Table A-6
DOCSIS Cable Downstream RF Specifications
Specification
System/Channel
RF channel spacing (bandwidth)
3
Transit delay
Carrier to noise ratio
Carrier to ingress power ratio
Composite triple beat distortion
Carrier to second order
Cross-modulation level
Amplitude ripple
Group delay
Micro reflections bound for dominant
echo
Carrier hum modulation
Burst noise
Seasonal/diurnal signal level variation
Cisco uBR7100 Series and Cisco uBR7100E Series Universal Broadband Router Hardware Installation Guide
A-4
1
DOCSIS Specifications
< 8 dB
< –50 dBc
+8 to +58 dBmV (QPSK)
+8 to +55 dBmV (16 QAM)
–16 to +26 dBmV
–6 to –10 dBc
DOCSIS Specifications
6 MHz
0.800 µsec
4
5
> 30 dB (64 QAM
)
5
> 35 dB (256 QAM)
> 35 dB
6
< -50 dBc
< –50 dBc
< –40 dBc
0.5 dB in 6 MHz
7
75 ns
in 6 MHz
–10 dBc @ < 0.5 µsec
–15 dBc @ < 1.0 µsec
–20 dBc @ < 1.5 µsec
–30 dBc @ < 1.5 µsec
< –26 dBc (5%)
< 25 µsec
8 dB
2
Minimum Settings
< 8 dB
< –50 dBc
+8 to +58 dBmV (QPSK)
+8 to +55 dBmV (16 QAM)
–10 to +25 dBmV
–6 to –10 dBc
1
2
Minimum Settings
6 MHz
0.800 µsec
5
>30 dB (64 QAM)
5
> 33 dB (256 QAM)
> 35 dB
< -50 dBc
< –50 dBc
< –40 dBc
0.5 dB in 6 MHz
75 ns in 6 MHz
–10 dBc @ < 0.5 µsec
–15 dBc @ < 1.0 µsec
–20 dBc @ < 1.5 µsec
–30 dBc @ < 1.5 µsec
< –26 dBc (5%)
< 25 µsec
8 dB
Appendix A
System Specifications
Your Headend Settings
Your Headend Settings
OL-5916-01
Advertisement
Table of Contents
Troubleshooting
