User's Manual

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8.3.7 Spectrum Management
Spectrum
Management Selection is the PTP 600 Series Bridge feature that monitors the
available wireless spectrum and directs both ends of the wireless link to operate on a channel
with a minimum level of co-channel and adjacent channel interference.
8.3.7.1 Wireless Channels
The PTP 600 Series Bridge operates using a set of predefined overlapping channels. There
are a different number of channels, depending on the raster mode selected. Each channel
occupies 30 MHz, 20 MHz, 15 MHz, 10 MHz or 5 MHz of wireless spectrum and is offset in
center frequency from its neighboring channel by 10 MHz or 6 MHz. It is important to note
that adjacent channels on the Spectrum management display have a 10 MHz or 6 MHz
overlap to the adjacent channel.
The default channelization can be modified by varying the lower center frequency attribute in
the installation wizard - see Section 8.3.4.4 “Wireless Configuration”. See Section 5.4
“Variable Channel Bandwidth Operation” and 5.10 “PTP 58600 Specific Frequency Planning
Con
siderations” for more detail.
8.3.7.2 Spectrum Management Measurements
The 600 Series Bridge performs two mean signal measurements per TDD cycle, per channel.
This mean measurement represents the mean received signal power for the 40 microseconds
measurement period.
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
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.