Alvarion BreezeMAX PRO 5000 CPE, Product Manual

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Chapter 4 - Operation BST/AU Parameters
BreezeMAX PRO 5000 CPE 63 Product Manual
4.7 BST/AU Parameters
The quest for load sharing together with the desire to create best throughput
conditions for the CPE created the need for the Best BS feature, to enable an CPE
to connect to the best BS in its neighborhood.
The CPE scans a set of frequencies (see “Radio Parameters” on page 67 ) 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 CPE define a set of BS IDs, and the
CPE 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
CPE 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 CPE. At the
end of the scanning period, the CPE 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 CPE 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
CPE 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 CPE: A Mobile
CPE is expected to move among different BSs, while a Nomadic CPE is typically
stationary although it may also be moved to the coverage area of a different BS.
If a Nomadic CPE loses communication with the selected BS, it will continue
searching for it for 4 minutes. If not found within 4 minutes, the CPE will scan the
frequencies from the discrete frequencies list and if it finds a preferred BS within
these frequencies it will associate with it. If the CPE does not find any BS at this
stage or cannot associate with any of the BSs found, it will move on to the Full
Scan.
The same process will be executed also for a Mobile CPE.
The same process will be executed following a reset of the CPE, with the exception
that the CPE retries connecting to the last connected BS for 2 minutes in case of
reset in the following situations:
» BS is preferred
» Preferred mask is not set