MT9079
Out of synchronization
YES
NO
Search for primary basic
frame alignment signal
RAI=1, Es=0.
YES
>914 CRC errors
in one second
3 consecutive
incorrect frame
alignment
NO
Verify Bit 2 of non-frame
alignment signal.
signals
YES
NO
Verify second occurrence
of frame alignment signal.
No CRC
multiframe alignment.
8 msec. timer expired*
YES
Primary basic frame synchronization
CRC-4 multi-frame alignment
CRC-4 multi-frame alignment
acquired. Enable traffic RAI=0, E’s=0. Start
loss of primary basic frame alignment
checking. Notes 7 & 8.
Search for multiframe
alignment signal.
Start 400 msec timer.
Note 7.
Note 7.
YES
NO
Basic frame
alignment
acquired
Multiframe synchronization
acquired as per G.732.
Note 7.
Start 8 msec timer.
Note 7.
Basic frame
alignment acquired
No CRC
multiframe
alignment.
NO
YES
8 msec. timer expired*
Find two CRC frame
alignment signals.
Note 7.
No CRC
Check for two consecutive errored
multiframe alignment signals.
Notes 7 & 8.
multiframe
alignment.
8 msec.
timer expired**
CRC multiframe
alignment
CRC-to-CRC interworking. Re-align to new
basic frame alignment. Start CRC-4 processing.
E-bits set as per G.704 and I.431. Indicate
CRC synchronization achieved.
Parallel search for new basic frame
alignment signal.
Notes 6 & 7.
Notes 7& 8.
400 msec timer expired
CRC-to-non-CRC interworking. Maintain
primary basic frame alignment. Continue to
send CRC-4 data, but stop CRC processing.
E-bits set to ‘0’. Indicate CRC-to-non-CRC
operation. Note 7.
*
only if CRC-4 synchronization is selected and automatic CRC-4 interworking is de-selected.
** only if automatic CRC-4 interworking is selected.
Figure 6 - Synchronization State Diagram
4-250
MITEL [ MITEL NETWORKS CORPORATION ]
