Motorola PTP 300 series User Manual page 97

MHz of wireless spectrum and is offset in center frequency from its neighboring channel by 5 MHz.
It is important to note that adjacent channels on the Spectrum management display have a 5 MHz
overlap to the adjacent channel.
The default channelization can be modified by varying the lower center frequency attribute in
the installation wizard - see
Considerations" for more detail.
8.3.7.2 Spectrum Management Measurements
Each end of the 300 Series Bridge performs a single measurement of the combined receiver input
power in an inactive portion of the TDD cycle. The measurement is made with an effective
bandwidth of 15 MHz on a single channel and includes the contribution from receiver noise.
The Spectrum Management algorithm collects measurements equally from all channels.
This process is called the Channel Availability Check (hereafter referred to by the acronym CAC).
The CAC uses a round-robin channel selection process to collect an equal amount of measurements
from each channel. It is important to note that the CAC measurement process 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 measure-
ment. 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 quantiza-
tion 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
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.
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The arithmetic mean is the true power mean and not the mean of the values expressed in dBm.
Web Page Reference
Section 8.3.4.3
"Wireless Configuration". See
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of the measured means during a quantization period.
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Section 5
"General