User's Guide Part 2

Installation pages Chapter 6 Operation
phn-0896_009v003
6-64
UNDER DEVELOPMENT
Feb 2010
NOTE
Because the 4.9 GHz spectrum is restricted by license, the Lower Center
Frequency is fixed for the PTP 49600 and is therefore not displayed.
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.
Default Raster
This is only displayed when Spectrum Management Control is set to “Fixed
Frequency”. If this is set to “On”, the list of options presented in the fixed Tx
frequency box is limited by the default raster.
Fixed Tx Frequency, Fixed Rx Frequency
This is only displayed when Spectrum Management Control is set to “Fixed
Frequency”. The software for the PTP 600 Series 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-channel
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 6-32 sh
ows an example of the fixed frequency configuration for a 30 MHz
channel bandwidth. In this example, the Fixed Transmit Frequency is set to 4436 MHz
and the Fixed Receive Frequency is set to 4436 MHz. Care must be taken when
configuring the Fixed Transmit and Receive Frequencies to ensure that both
frequencies are on the same channel raster as the Lower Center Frequency. For
example, if the channel raster is 10 MHz, both the Fixed Transmit and Receive
Frequencies must be a multiple of 10 MHz from the Lower Center Frequency (4426 =
4416 + 10 MHz) and (4486 = 4416 + 10 MHz × 7).
NOTE
A raster limits the selection of the Rx frequency based upon the setting of
the Tx frequency.