User guide

45 Mbps Backhaul User Guide
Issue 3, December 2004 Page 58 of 113
Figure 27 Spectrum Management as seen from the Slave
6.3.5.5 Spectrum Management Configuration
The following section describes the user modifiable configuration assessible from the DFS webpage. It is
recommended that the default values are maintained. If the user believes that the performance of the DFS
algorithm requires some modifications this should only be done after consulting your distributor or one of the
Motorola field support engineers.
Refresh Page Period The DFS page refreshes automatically according to the setting entered here (in seconds).
Hopping Period The DFS algorithm evaluates the DFS metrics every ‘Hopping Period’ seconds (180 seconds by
default) looking for a channel with lower levels of interference. If a better channel is located then DFS performs
an automated channel hop. If SNMP and or SMTP alerts are enabled an SNMP TRAP and or an email alert is
sent warning the system administrator of the channel change. (Default 180 Seconds).
Hopping Margin DFS uses this margin when making a channel hop decision. The channel to hop to has to have
an interference level 3 dBs (default) better than the current active channel. (Default 3 dB)
Hopping Counter is used to record the number of channel hops. The number in the “(+ )” brackets indicates the
number of channel changes since the last screen refresh.
Asymmetric DFS. The default configuration of symmetric constrains DFS to operate symmetrically using the
same transmit and receive channel. When in symmetric mode the slave unit will always follow the master. If the
master moves to a new channel the slave will hop to the same channel. When the Point-to-Point link is
configured as an asymmetric link both the master and slave a free to select the best channel from their own set
of local interference metrics. (Default Symmetric).