User's Manual

Chapter 4 - Operation BST/AU Parameters
BreezeMAX PRO 5000 CPE 61 Product Manual
4.7 BST/AU Parameters
The quest for load sharing together with the desire to create best throughput
conditions for the SU created the need for the Best BS feature, to enable an SU to
connect to the best BS in its neighborhood.
The SU scans a set of frequencies (see “Radio Parameters” on page 65) searching
for BSs it can communicate with. Each BS in the network is configured with a
unique BS ID. The BS ID parameters in the SU define a set of BS IDs, and the SU
is allowed to communicate only with BSs whose BS ID is included in the BS IDs
range defined by the applicable parameters. Each of the BSs with which the SU
can communicate (perform initial phase of network entry) is given a quality mark
based on the quality of the signal at which it is received by the SU. At the end of
the scanning period, the SU reaches a Best BS decision according to the
information gathered. The BS with the highest quality mark is selected as the Best
BS, and the SU will immediately try to associate with it at the relevant
frequency/bandwidth.
The range used for scanning is defined by the BS ID and BS ID Mask parameters.
The initial range can be limited by defining a preferred range of BSs, and selecting
the best BS in the preferred range. If no device is found in the preferred range, the
SU will scan the entire range.
A Mobility Mode parameter enables supporting optimal performance after loosing
connectivity to the BS according to the expected mobility of the SU: A Mobile SU is
expected to move among different BSs, while a Nomadic SU is typically stationary
although it may also be moved to the coverage area of a different BS.
If a Nomadic SU loses communication with the selected BS, it will continue
searching for it for 5 minutes. If not found within 5 minutes, the SU initiates a
short scan and will try to associate with the second BS in the of Best BS Table and
so on, checking all the BSs in the table, and trying to associate with the best one.
If no BS from the table is found, the Best BSs table will be cleared and the SU will
initiate a Full Scan (all defined scanning frequencies/bandwidths and all BSs in
the defined range).
The same process will be executed also for a Mobile SU, with one exception: The
SU will search for the BS to which it was previously connected only for 100
milliseconds to allow faster association with a new BS.
The same process will be executed following a reset of the SU, with the exception
that the SU will search for the BS to which it was previously connected for one
minute only.