Alvarion BreezeACCESS II, Системное руководство, Страница: 155 / 324

Menus and Parameters
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BreezeACCESS Version 4.5 System Manual
AU Alarms (IF-based AU Only)
The AU Alarms feature enables to identify and alert upon the detection
of a potential problem in the outdoor unit of the AU, or another problem
that causes significant degradation in the performance of the wireless
link.
When the AU Alarms Option is enabled, three types of tests are
performed: Traffic Statistics tests, Power tests and Associations test.
Information is gathered continuously and various calculations used for
decision making are performed each test cycle period that is defined by
the configurable
Test Cycl e parameter. Alarms can be generated only
after a sufficient time, defined by the configurable Learning Period
parameter, has elapsed since the last reset (or since the AU Alarm
Option was enabled).
Traffic Statistics Tests
The AU gathers traffic information that is used to calculate various
traffic statistics. The calculated statistics are used for estimating the
performance of the wireless link. The following traffic statistics rates are
calculated for each test cycle period:
a. Current Retransmission Rate - Defined as Nr/(Nt+ Nr),
Where:
Nr - Number of retransmissions during the last test cycle
period.
Nt - Number of successfully transmitted unicast frames
during the last test cycle. The minimum value of Nt+ Nr for a
meaningful test is 50 (otherwise the result is NA).
b. Current Dropped Frames Rate - Defined as Nd/Nt, where
Nd is the number of dropped frames during the last test
cycle period. Dropped frames are frames that were drooped
because they were retransmitted to the extent of the
maximum allowed number of retransmissions without being
acknowledged. The minimum value of Nt for a meaningful
test is 50 (otherwise the result is NA).
c. Current CRC Error Rate - Defined as Ncrc/(Nrx+Ncrc),
where:
Ncrc - Number of frames received with a CRC error during
the last test cycle period.
Nrx - Number of successfully received frames during the last
test cycle period.
The minimum value of Nrx+Ncrc for a meaningful test is 50
(otherwise the result is NA).
d. Current Duplicate Frames Rate - Defined as Ndup/Nrx,
where Ndup is the number of dropped frames during the last
test cycle period. The minimum value of Nrx for a meaningful
test is 50 (otherwise the result is NA).