User's Manual

Menus and Parameters
Manual Revision 1.0
4-47
Best AU Parameters (SU)
An SU that can communicate with more than one AU using the same
ESSID may become associated with the first AU it "finds", not
necessarily the best choice in terms of quality of communication or
other factors such as number of SUs serviced by each AU. The same
limitation also exists if only one AU in the neighborhood has an ESSID
identical to the one used by the SU, since it is not always necessarily
the best choice.
The topology of a fixed access network is constantly changing. Changes
in base station deployment and subscriber density can accumulate to
create substantial changes in SU performance. The quest for load
sharing together with the desire to create best throughput conditions for
the SU created the need for the Best AU feature, to enable a SU to
connect to the best AU in its neighborhood.
When the Best AU feature is used, each of the AUs is given a quality
mark based on the level at which it is received by the SU. The SU scans
for a configured number of cycles, gathering information from all the
AUs it can communicate with. At the end of the scanning period, the SU
reaches a Best AU decision according to the information gathered. The
AU with the highest quality mark is selected as the Best AU, and the SU
will immediately try to associate with it. The quality mark given to each
AU depends on the level at which it is received by the SU.
The Best AU selection mechanism can be overridden by defining a
specific AU as the preferred AU.
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.
The Best AU Parameters menu includes the following options:
Best AU Support
The Best AU Support option enables or disables the Best AU selection
feature.
The default is Disable.
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.