| Description | This attribute provides an upstream in-channel Carrier-to-Noise
plus Interference Ratio (CNIR). CNIR
is defined as the ratio of the expected commanded
received signal power at the CMTS input, assuming
QPSK0 modulation, to the noise plus
interference in the channel.
This measurement occurs prior to the point at which
the desired CM signal, when present, is demodulated.
The measurement includes the effect of the receive matched
filter but does not include the effect of any ingress filtering.
Both the signal power and noise/interference power
are referenced to the same point, e.g., CMTS input. |