Transmission Interface Handling G.703 2048 kbit/s
A new period of available state begins at the onset of Q consecutive
seconds with no SES detected. These Q seconds are considered to be
part of the available time.
32.3.5
Supervision of Transmission Quality
The function is initiated when the AO DP is enabled from the BSC.
The configuration of quality supervision can only be performed when
the AO DP is in state “Disable”. The reporting to the BSC is performed
when the AO DP is in state “Enable”.
Quality supervision consists of six supervision functions:
•
BFF (Bit Fault Frequency)
•
DF (Disturbance Frequency)
•
SF (Slip Frequency)
•
ES (Errored Seconds)
•
SES (Severely Errored Seconds)
•
UAS (Unavailable Seconds)
Bit Fault Frequency supervision
The frame alignment word in time slot 0 in even frames is used to
determine an error rate. The actual error rate is established by taking
the number of faulty frame alignment words and dividing them by the
total number of checked bits during the BI (Base Interval).
The bit fault frequency is supervised and reported as the mean bit error
ratio in ppm (parts per million) during the BI.
Disturbance Frequency supervision
This supervision monitors the detected fault situations which are
regarded as disturbances upon detection. Upon detection the following
events are regarded as disturbances:
•
LOF (Loss Of Frame) alignment
•
LOS (Loss Of Signal)
•
AIS (Alarm Indication Signal)
•
RAI (Remote Alarm Indication) received from remote end
Two disturbance frequency counters exist. Both are derived from the
downstream PCM port, but one is closely connected to downstream
faults while the other one is related to upstream faults.
The DF downstream counter is incremented by 1 for each occurrence of
•
LOF or
•
LOS or
•
AIS
The DF upstream counter is incremented by 1 for each occurrence of
RAI.
EN/LZT 123 2697
R5A
1998-08-13
193 (306)
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