Appendix B RF Specifications
DOCSIS 1.0 Transmission Characteristics
Table
Parameter | Value |
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Seasonal and diurnal signal level variation | 8 dB |
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Maximum analog video carrier level at the cable modem | 17 dBmV |
input, inclusive of above signal level variation |
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Lowest analog video carrier level at the cable modem input, | |
inclusive of above signal level variation |
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1.For measurements above the normal operating frequency band (except hum), impairments are referenced to the
2.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, the
3.Decibels relative to carrier, a common measurement in RF engineering to specify the power of a sideband in a modulated signal relative to the carrier in decibels.
4.For hum measurements above the normal downstream operating frequency band, a
Upstream RF Channel Transmission Characteristics
Transmission is from the cable modem output at the customer location to the headend. Measurement methods are defined in NCTA or CableLabs2 documentation.
Table | DOCSIS 1.0 Assumed Upstream RF Channel Transmission Characteristics | |
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Parameter |
| Value |
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Frequency range |
| 5 to 42 MHz edge to edge |
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| |
Transit delay from the most distant cable modem to the | ≤ 0.800 msec (typically much less) | |
nearest cable modem or CMTS |
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Not less than 25 dB | ||
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Not less than 25 dB1 | ||
ingress signals) ratio |
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Not less than 25 dB | ||
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Carrier hum modulation | Not greater than | |
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Burst noise |
| Not longer than 10 μsec at a |
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Amplitude ripple | 5 to 42 MHz: 0.5 dB/MHz | |
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Group delay ripple | 5 to 42 MHz: 200 ns/MHz | |
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Seasonal and diurnal signal level variation | Not greater than 8 dB min to max | |
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1.Ingress avoidance or tolerance techniques may be used to ensure operation in the presence of time varying discrete ingress signals that could be as high as 0 dBc. (CableLabs1)
2.Amplitude and frequency characteristics sufficiently strong to partially or wholly mask the data carrier.
3.Impulse noise levels more prevalent at lower frequencies (<15 MHz).
Cisco uBR7225VXR Universal Broadband Router Hardware Installation Guide
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