System information

BSR 64000 Configuration and Management Guide
6-78
The hopping threshold error rate is determined by the Forward Error Correction
(FEC) error-rate threshold value. If the error-rate threshold is configured, the
spectrum manager periodically polls the signal quality table of the member channels
to compute the error rate during the polling interval. If the error rate exceeds the
threshold, it triggers spectrum hopping for the affected channel. The error rate is a
fraction of 1000.
The default hopping threshold error rate is 10 or 1 percent. Use the hop threshold
error command in Cable Spectrum Group mode to adjust the acceptable hopping
threshold error rate, as shown below:
MOT(config-spcgrp:<WORD>)#hop threshold error {<num:1-1000>}
where:
WORD is the spectrum group name.
num:1-1000 is the error rate as a fraction of 1000.
For example, an error rate of 1 implies 0.1 percent or an error rate of 1000 implies
100 percent.
Configuring the Spectrum Hopping Flap Threshold
A frequency hopping flap threshold is configured as a criteria to apply the hopping
rules in instances when one or a minimal number of cable modems (CMs) loose their
connection with the BSR (Flap).
The frequency hopping flap threshold is determined by the percentage of CMs that
loose their connectivity. If the flap threshold is configured, the spectrum manager
periodically scans the flap-list table of the member channels to compute the flap rate
during the scan interval. If the flap rate exceeds the threshold, it triggers spectrum
hopping for the affected channel.
This frequency hopping threshold is activated with a value of 0 percent by default to
prevent the unnecessary triggering of a hopping action. For example, if the
downstream cable is disconnected or the downstream frequency is changed, these
actions would cause all CMs on the network to flap.