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Target Range Installers that know the range between the two wireless units to within ± 1 km
can use the target range mode. The main advantage of the target range mode is that it
reduces the time taken by the units to range. To use the target range mode the installer
MUST select Target Range as the ranging mode and enter the approximate range in km in
the Target range data entry field at both ends of the link.
Spectrum Management Control Is used to configure the 150/300 Mbps Backhaul Spectrum
Management features, see section 8.3.6 for more details. i_DFS is the abbreviation for
intelligent Dynamic Frequency Selection, this feature continually monitors the 5.8 GHz
spectrum looking for the channel with the lowest level of on channel and co-channel
interference. Fixed frequency mode allows the installer to fix the transmit and receive
frequencies on the units. The frequencies may be configured symmetrically or
asymmetrically. In WiMAX mode the system administrator / installer can assign WiMAX
compatible channelizations. An additional side effect of configuring the wireless in WiMAX
mode is to enable the WiMAX SNMP MIB support ( Figure 42 ) shows an example of WiMAX
configuration
Lower Center Frequency The 150/300 Mbps Backhaul software allows a user to optionally
adjust the channel center frequencies. The default starting channel center frequency is 5742
MHz. This value can be adjusted between 5740 and 5748 MHz. Changing the Lower Center
Frequency attribute causes all channel center frequencies to be offset. It effectively slides the
channelization up or down.
Warning: The lower centre frequency attribute must be configured to the same value for of
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 Canopy 150/300 Mb BH
software 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 5.8 GHz
interference environment Figure 41 shows an example fixed frequency configuration. 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).
Issue 1.1 April 2006
Page 80
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