Motorola Canopy 300 Mbps Backhaul User Manual page 90

is not altered by the channel barring process. Measurements are still collected for all
channels irrespective of the number of barred channels.
8.3.7.3 Measurement Analysis
Spectrum Management uses statistical analysis to process the received peak and mean
measurement. The statistical analysis is based on a fixed, one minute, measurement
quantization period. Spectrum Management collects data for the specified quantization period
and only at the end of the period is the statistical analysis performed.
The analysis produces three key metrics for each channel:
•
Peak of Means
•
99.9% Percentile of the Means
•
Mean of Means
Peak of Means is the largest mean interference measurement encountered during the
quantization period. The peak of means is similar to the peak of peaks and is useful for
detecting slightly longer duration spikes in the interference environment.
99.9% Percentile of the Means is the value of mean interference measurement which 99.9%
of all mean measurements fall below, during the quantization period. The 99.9% percentile
metric is useful for detecting short duration repetitive interference that by its very nature has a
minimal effect of the mean of means.
Mean of Means is the arithmetic mean
period. The mean of means is a coarse measure of signal interference and gives an
indication of the average interference level measured during the quantization period. The
metric is not very good at predicting intermittent interference and is included to show the
spread between the mean of means, the 99.9% percentile and the peak of means.
Important Note: Spectrum Management uses the 99.9% percentile as the prime interference
measurement. All subsequent references to interference level refer to this percentile
measurement.
The display of statistical measurement on the spectrum management page always shows a
statistical summary of all channel measurement. The statistical summary is controlled by the
Statistics Window attribute. This attribute defaults to a value of twenty minutes, which means
that the mean and percentile values displayed for each channel are calculated over the 20
minute period. All channel decisions are made using the values computed over the statistics
window period.
8.3.7.4 The Spectrum Management Master / Slave Relationship
By default Spectrum Management operates in a master / slave relationship. The master is
assumed to be the link master configured during installation. All Spectrum Management
configuration changes MUST be performed from the master, to enforce this the Spectrum
Management webpage has a different appearance depending if you are viewing the data from
the master or slave.
All configuration changes are applied at the master only. All configuration changes are
messaged from the master to the slave. Any Spectrum Management configuration messages
received at the slave are stored in non-volatile memory. This enables both master and slave
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The arithmetic mean is the true power mean and not the mean of the values expressed in dBm.
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of the measured means during a quantization
T P F FP T
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