User's Manual

Menus and Parameters
2-35
BreezeACCESS 4.0 System Manual
The Best AU selection mechanism can be overridden by defining a
specific AU as the preferred AU.
! Best AU Parameters in SU
" Best AU Support – Enables or disables the Best AU selection
feature.
The default is Disable.
" Number of Scanning Attempts – Defines the number of
scanning cycles to be used for gathering information on
neighboring AUs. A higher number may result in a better
decision at the cost of an increased scanning time during
which the SU is not operational.
Valid values: 1 - 255.
Default value: 20.
The scanning time can be calculated based on the following
formula:
Scanning Time (secs) = N * C * 0.019
N = Number of scanning attempts
C = Number of channels in the hopping sequence
0.019 seconds is the time spent on each channel (dwell time)
while in scanning mode.
" Preferred AU MAC Address – Defines a specific AU with
which the SU should associate. Gaining control of the SUs
association is a powerful tool in network management. The
Preferred AU MAC Address parameter is intended for
applications where there is a need to dictate the preferred AU
with whom the SU should associate. To prevent the SU from
associating with the first viable AU it finds, the Best AU
Support mechanism should be enabled. Once the SU has
identified the preferred AU based on its MAC address, it will
associate with it and terminate the scanning process. If the
preferred AU is not found, the SU will associate with an AU
according to the decision reached using the best AU
algorithm.
NOTE:
Although the SU selects the Best AU based on long-term conditions prior to the decision
time, it may not always be connected to the instantaneous Best AU at any given time.
Note also that the decision is done only once during the scanning interval. The decision
may not remain the optimal one for ever. If there are significant changes in deployment
of neighboring AUs and the SUs served by them, overall performance may be improved
if the applicable SUs are reset intentionally so as to re-initiate the Best AU decision
process.
NOTE:
If the Best AU feature is not used, the SU associates with the first AU it finds
whose ESSID or Operator ESSID is identical to its own ESSID.