User manual

Chapter 2 - Managing a Single Device/Cell Air Interface Frequency Page
AlvariCRAFT Device Manager 47 User Manual
according to the bandwidth. For instance, if the bandwidth is 20 MHz, then if
radar activity was detected in 5800 MHz, frequencies 5790 MHz and 5810 MHz
should not be used as well. These frequencies are marked in the database as
Adjacent to Radar, and will be treated the same as Radar Detected frequencies.
Before ceasing transmission on the frequency where radar signals had been
detected, the AU/BU sends a special disassociation message to its associated
SUs/RB. This message includes an indication whether the SUs/RB should wait
for this AU/BU. If the SUs/RB should wait, the message includes also the waiting
time. During this time each SU/RB searches for the AU/BU in the defined
frequencies subset. If the AU/BU was not found within the waiting time, or if a
waiting request was not included in the message, the SU/RB starts searching for
any AU/BU, using the Best AU/BU mechanism if applicable.
Typically, operators prefer to preserve the original frequency planning and to
avoid moving to a new channel unless they are sure that there is a continuous
radar activity in the original channel. It should be noted that detection of radar
activity does not necessarily indicate a continuous radar activity in the channel. A
channel reuse algorithm enables returning to the original channel under certain
conditions that indicates low radar activity on the channel.
Starting on SW version 5.2, the DFS feature is supported (although disabled by
default) for units using Country Codes 1060 and 1064 (Universal 5.4 GHz and
Universal 5.8 GHz). When a unit using either one of these Country Codes is
upgraded from a SW version lower than 5.2 the feature will not be automatically
applicable. If the user wants to use the DFS feature he must re-apply the Country
Code values. Note also that for these units, if the user changes the working
sub-band the DFS Option will be automatically be set to No. For other Country
Codes that support DFS when sub-band is changed the DFS Option is forced to
Yes. If DFS is enabled in these units the user can select the DFS algorithm to be
used (ETSI or FCC).