Motorola PTP 600 Series User Manual page 108

Spectrum Management Control: Is used to configure the PTP 600 Series Bridge's
Spectrum Management features, see section 8.3.7 for more details. I-DFS is the abbreviation
for intelligent Dynamic Frequency Selection. This feature continually monitors the spectrum
looking for the channel with the lowest level of on channel and co-channel interference. Fixed
frequency mode allows the installer to fix transmit and receive frequencies on the units. The
frequencies may be configured symmetrically or asymmetrically.
Lower Center Frequency: The software for the PTP 600 Series Bridge allows a user to
optionally adjust the channel center frequencies. Changing the Lower Center Frequency
attribute causes all channel center frequencies to be offset. It effectively slides the
channelization up or down. See Sections 5.4 and 0 for more detail.
Warning: The lower center frequency attribute must be configured to the same value for both
the master and slave. Failure to do so will cause the wireless link to fail reestablishment. The
only way to recover from this situation is to modify the Lower Center Frequency attribute so
that they are identical on both the master and slave unit.
Fixed Transmit Frequency, Fixed Receive Frequency: The software for the PTP 600
Series Bridge allows a user to optionally fix transmit and receive frequencies for a wireless
link. The settings must be compatible at each end of the link. Once configured the spectrum
management software will not attempt to move the wireless link to a channel with lower co or
adjacent channel interference. Therefore this mode of operation is only recommended for
deployments where the installer has a good understanding the prevailing interference
environment. Figure 49 shows a sample fixed frequency configuration. In the example the
lower center frequency is set to its default values and the Fixed Transmit Frequency is set to
5742 MHz and the Fixed Receive Frequency is set to 5742 MHz. Care must be taken when
configuring the Fixed Transmit and Receive Frequencies to ensure that both frequencies are
on the same 10 MHz channel raster as the Lower Center Frequency. For example both the
Fixed Transmit and Receive Frequencies must be a multiple of 10 MHz from the Lower
Center Frequency (5752 = 5742 + 10 MHz) and (5782 = 5742 + 10 MHz × 3). See Sections
5.4 and 0 for more detail.
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