PM5366-PI PMC-Sierra, Inc., PM5366-PI Datasheet - Page 79

• Manufacturer Part Number: PM5366-PI
• Description: HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER AND M13 MULTIPLEXER
• Manufacturer: PMC-Sierra, Inc.

PRELIMINARY
DATASHEET
PMC-2010672
9.4 E1 Performance Monitoring
PROPRIETARY AND CONFIDENTIAL
CI is cleared upon deassertion of RAI or upon 28 consecutive 40ms intervals
without validation of “00111110 11111111”.
By definition, AIS-CI is a repetitive pattern of 1.26 seconds. It consists of 1.11
seconds of an unframed all ones pattern and 0.15 seconds of all ones modified
by the AIS-CI signature. The AIS-CI signature is a repetitive pattern 6176 bits in
length in which, if the first bit is numbered bit 0, bits 3088, 3474 and 5790 are
logical zeros and all other bits in the pattern are logical ones. AIS-CI is an
unframed pattern, so it is defined for all framing formats.
AIS-CI is declared between 1.40 and 2.56 seconds after initiation of the AIS-CI
signal and is deasserted 16.6 seconds after it ceases.
E1 framing can be performed on up to three sets of 21 tributaries for the purpose
of performance monitoring. The ingress or egress path may be monitored, as
selected on an indiividual tributary basis.
The E1 framing function searches for basic frame alignment, CRC multiframe
alignment, and channel associated signaling (CAS) multiframe alignment in the
incoming recovered PCM stream.
Once basic (or FAS) frame alignment has been found, the incoming PCM data
stream is continuously monitored for FAS/NFAS framing bit errors, which are
accumulated in a framing bit error counter dedicated to each tributary. Once
CRC multiframe alignment has been found, the PCM data stream is continuously
monitored for CRC multiframe alignment pattern errors and CRC-4 errors, which
are accumulated in a CRC error counter dedicated to each tributary. Once CAS
multiframe alignment has been found, the PCM data is continuously monitored
for CAS multiframe alignment pattern errors. The E1 framer also detects and
indicates loss of basic frame, loss of CRC multiframe, and loss of CAS
multiframe, based on user-selectable criteria. The reframe operation can be
initiated by software, by excessive CRC errors, or when CRC multiframe
alignment is not found within 400 ms.
The E1 framer extracts the contents of the International bits (from both the FAS
frames and the NFAS frames), the National bits, and the Extra bits (from timeslot
16 of frame 0 of the CAS multiframe). Moreover, the framer also extracts
submultiframe-aligned 4-bit codewords from each of the National bit positions
Sa4 to Sa8, and stores them in microprocessor-accessible registers that are
updated every CRC submultiframe.
The E1 framer identifies the raw bit values for the Remote (or distant frame)
Alarm (bit 3 in timeslot 0 of NFAS frames) and the Remote Signaling Multiframe
ISSUE 1
67
HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER
AND M13 MULTIPLEXER
PM5366 TEMAP-84