Monitoring Line Quality (Performance Monitoring) - NEC UPD98413 User Manual

3.4.6 Monitoring Line Quality (Performance Monitoring)

(1) Transmission performance monitoring-related functions
To monitor a sign error to maintain the line quality at the transmission side, a Bit Interleaved Parity (BIP)
operation is performed on a specific area and the result is inserted as an OH byte. In addition, the number of
Interleaved Bit Blocks in which an error has been detected at the reception side is inserted in the OH byte at the
transmission side and transmitted to the upstream side.
(a) Bit Interleaved Parity (BIP)
(i) B1 byte (Section BIP-8)
BIP-8 operation is performed on all the bits in frames after frame descramble, and the result of this
operation is inserted in the B1 byte before frame scramble of the next frame, then transmitted.
1 frame
9 rows
1 frame
9 rows
(ii) B2 byte (Line BIP-96)
BIP-96 operation is performed on all the bits of the frames before frame scramble, except the bits on
the first through third lines of SOH, and the result of this operation is inserted in the B2 byte before
frame scramble of the next frame, and transmitted.
1 frame
9 rows
1 frame
CHAPTER 3 FUNCTIONAL OUTLINE
SOH
AU pointer
B1
SOH
AU pointer
: BIP operation range
36 bytes
3 rows
AU pointer
6 rows
AU pointer
9 rows
B2 × × × × 12
: BIP operation range B2 × 12: BIP operation result of preceding
PRELIMINARY
1,080 bytes
After scramble
Before scramble
B1: BIP-8 operation result of preceding
1,080 bytes
Before scramble
Before scramble
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