Motorola PTP 600 System User Manual page 138

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 web page 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. These changes are then 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 to keep
identical copies of Spectrum Management configuration data in their non-volatile memories. It
is therefore possible to swap master and slave roles on an active Point-to-Point link without
modifying Spectrum Management configuration.
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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
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