Cisco Systems UBR7225VXR specifications EuroDOCSIS Transmission Characteristics

Appendix B RF Specifications

EuroDOCSIS Transmission Characteristics

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 B-6 DOCSIS 1.1 Assumed Upstream RF Channel Transmission Characteristics

Parameter	Value
Frequency range	5 to 42 MHz edge to edge
Transit delay from the most distant cable modem to the	≤ 0.800 msec (typically much less)
nearest cable modem or CMTS
Carrier-to-interference plus ingress (the sum of noise,	Not less than 25 dB1
distortion, common-path distortion, and cross-modulation
and the sum of discrete and broadband ingress signals,
impulse noise excluded) ratio
Carrier hum modulation	Not greater than –23 dBc (7%)
Burst noise	Not longer than 10 microseconds at a 1-kHz average rate for
	most cases2, 3
Amplitude ripple	5 to 42 MHz: 0.5 dB/MHz
Group delay ripple	5 to 42 MHz: 200 ns/MHz
Micro-reflections—single echo	–10 dBc @ ≤ 0.5 microseconds
	–20 dBc @ ≤ 1.0 microseconds
	–30 dBc @ > 1.0 microseconds
Seasonal and diurnal reverse gain (loss) variation	Not greater than 14 dB min to max

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 10 dBc. Ratios are guaranteed only within the digital carrier channels.

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).

EuroDOCSIS Transmission Characteristics

The following tables provide information on the assumed RF channel transmission characteristics for EuroDOCSIS.

Cisco uBR7225VXR Universal Broadband Router Hardware Installation Guide

OL-17309-02 B-5