User Manual

Table Of Contents
8 Web Page Reference
110
Lower Center Frequency: The software for the PTP 500 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 Section 5.5PTP 54500 Specific Frequency Planning
Considerations” and Section 5.6PTP 58500 Specific Frequency Planning Considerations
depending on the frequency variant.
CAUTION: 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 500
Series Bridge allows a user to optionally fix the Transmit and the 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 of the prevailing
interference environment. Figure 47 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 5735 MHz and the Fixed Receive Frequency is set to 5735 MHz. Care
must be taken when configuring the Fixed Transmit and Receive Frequencies to ensure that
both frequencies are on the same 5 MHz channel raster as the Lower Center Frequency. For
example both the Fixed Transmit and Receive Frequencies must be a multiple of 5 MHz from
the Lower Center Frequency (5740 = 5735 + 5 MHz) and (5745 = 5735 + 5 MHz x 2). Please
note that there is a raster that limits the selection of the Rx frequency based upon the setting
of the Tx frequency, and that the list of options presented in the fixed Tx frequency box is
limited to that raster.