Alvarion BREEZEACCESS SW VERSION 5.1 Manual Do Utilizador

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Chapter 4 - Operation and Administration 
 
BreezeACCESS VL System Manual
 
138 
information on how to view the Sub-Bands supported by the unit and the 
supported parameters’ values and options, refer to section 
4.2.2.4
The range depends on the number of Sub-Bands supported by the country code. 
The default selection is Sub-Band 1 
4.2.6.2.5.2 User 
Defined Frequency Subsets 
The User Defined Frequency Subsets menu enables defining for each of the 
available Sub-Bands the frequencies that will be used by the SU when scanning 
for an AU. For each available Sub-Band, the available frequencies are displayed, 
and an index is associated with each frequency. Enter either the desired 
frequency indexes, ‘A’ (All) for using all frequencies in the subset or ‘N’ (None) for 
not scanning that sub-band. 
The default is all frequencies in all available sub-bands. 
4.2.6.2.5.3 Show 
Frequency Definitions 
Upon selecting the Show Frequency Definitions, the selected frequencies in the 
available Sub-Bands and the current operating frequency are displayed.  
4.2.6.2.6  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. The same limitation also exists if only one AU 
in the neighborhood has an ESSID identical to the one used by the SU, as 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 an 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 with which it can 
communicate. 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.