User guide

45 Mbps Backhaul User Guide
Issue 3, December 2004 Page 63 of 113
mode of operation is only recommended for deployments where the installer has a good understanding the
prevailing 5.8 GHz interference environment. Figure 19 shows an example fixed frequency configuration. The
lower center frequency is set to its default value and the Fixed Transmit Frequency is set to 5740 MHz and the
Fixed Receive Frequency is set to 5782 MHz. Care must be taken when configuring the Fixed Transmit and
Receive Frequencies to ensure that both frequencies are on the same 6 MHz channel raster as the Lower Center
Frequency. For example both the Fixed Transmit and Receive Frequencies must be a multiple of 6 MHz from
the Lower Center Frequency (5740 = 5734 + 6 MHz) and (5782 = 5734 + 6 MHz × 8). To help the user when
identifying the mode of operation Spectrum management uses two visual cues. See Figure 32. The main page
title identifies the mode of operation using the ‘- Fixed Frequency Mode’ postfix., and the selected channels are
identified by a red capital ‘F’.
Figure 32: Spectrum Management Fixed Frequency Screen
Channel barring is disabled in fixed frequency mode as it is not required as dynamic channel hopping is
prohibited in this mode.
The only controls available to the master are the Statistics Window and Interference Threshold attributes. They
will have no effect of the operation of the wireless link and will only effect the generation of the channel
spectrum graphics.
The active channel history menu is removed in this mode of operation as channel hopping is prohibited.
6.3.7 Spectrum Management (UK - Region 4)
To comply with the UK radar avoidance and Road Traffic Tolling (RTT) regulations. Spectrum Management
when the 45 Mbps Backhaul is configured in region 4 has specific behavioral traits. These behavioral traits can