Transmission Interface Handling DS1 1544 kbit/s
ERATE ceases
The ERATE condition ceases when the bit error rate is less than 1*10
–3
during time T.
AIS commences
LOF and a continuous received stream of 1’s during 24 frames (all-
ones) is detected. The "all-ones" are detectable in the presence of a
1*10
–3
BER (Bit Error Rate).
AIS ceases
When at least one of the conditions LOF and “all-ones” is cleared.
RAI commences
At least four consecutive 16-bit patterns consisting of eight 1’s followed
by eight 0’s (i.e. 4 times 1111111100000000), is detected over the ESF
data link. The signal is detected in less than one second and in the
presence of a 1*10
–3
BER.
RAI ceases
The RAI signal pattern does not occur in 8 to 13 contiguous 16-bit
signal pattern intervals.
UAST commences
UAST commences when unavailable state is declared. Each direction
(upstream and downstream) is supervised independently of the other.
Together with the alarm status, time information for each direction of
UAST is reported to the BSC. When UAST commences, zero is
reported as time information. When UAST ceases, the time that the
UAST alarm has been activated is reported.
When the BSC requests the alarm status, two scenarios are possible:
UAST is activated and UAST is not activated. If it is activated, zero is
reported as time information. Otherwise, the time that the UAST alarm
was activated the latest time, is reported to the BSC.
UAST ceases
UAST ceases when available state is declared. Each direction (upstream
and downstream) is supervised independently of the other.
33.3.5
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)
206 (306)
EN/LZT 123 2697
R5A
1998-08-13
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