Cisco Systems UBR7225VXR specifications Upstream RF Channel Transmission Characteristics

Appendix B RF Specifications

EuroDOCSIS Transmission Characteristics

3.For hum measurements above the normal downstream operating frequency band, a continuous-wave carrier is sent to the test frequency at the same level as the highest-frequency PAL/SECAM carrier.

Upstream RF Channel Transmission Characteristics

Transmission is from the cable modem output at the customer location to the headend.

Table B-8	EuroDOCSIS Assumed Upstream RF Channel Transmission Characteristics
Parameter		Value
Frequency range		5 up to 65 MHz to edge
Transit delay from the most distant cable modem to the		≤ 0.800 msec (typically much less)
nearest cable modem or cable modem termination system
Carrier-to-noise ratio in active channel		Not less than 22 dB
Carrier-to-ingress power (the sum of discrete and broadband		Not less than 22 dB1
ingress signals) ratio in active channel
Carrier-to-interference (the sum of noise, distortion,		Not less than 22 dB
common-path distortion, and cross-modulation) ratio in
active channel
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 65 MHz: 2.5 dB in 2 MHz
Group delay ripple		5 to 65 MHz: 300 ns in 2 MHz
Micro-reflections—single echo		–10 dBc @ ≤ 0.5 microseconds
		–20 dBc @ ≤ 1.0 microseconds
		–30 dBc @ > 1.0 microseconds
Seasonal and diurnal signal level variation		Not greater than 12 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 0 dBc.

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

OL-17309-02 B-7