Alcatel 1850 TSS-320 Technical Handbook page 57

3.4.3.1 Source Side (Signal flow from HPC matrix to Optical line)
Backpanel Aligner:
performs Alignment processing on proprietary 4G Backplane Frame Format signals at 3.11 Gb/s
coming from HPC matrix A and B
Descrambler+DEFEC+Label extraction:
performs descrambling; FEC decoding, error detection, corrected/uncorrected errored blocks count;
J0Link extraction.
EPS Protection Sk:
performs the selection (for EPS protection purposes) between link from HPC matrix A and link from
HPC matrix B.
OverHead extraction+Deslicer+Rate Adapter:
Overhead and Protection channels extraction and transmission to FERMAT; adaptation from
backpanel rate to SDH rate
HVC After Matrix (HTCM/HTCTsk, HPOM/HSUTsk, HSUTso, HTCTso):
performs path overhead handling: N1 insertion, BIP-8 (B3) compensation, C2 "unequipped"
insertion, J1 and G1 insertion, BIP-8 (B3) calculation and insertion
MSA So (MSn/Sn_A_So):
performs AUG assembly, AU4 pointer generation and processing, AU-AIS generation and PJE
count.
MST So (MSn_TT_So):
MS-REI and MS-RDI insertion, D4-D12, K1-K2 and MSOH OverHead bytes insertion.
RST*So (partial RSn_TT_So):
performs regenerator section trace (J0) insertion, D1-D3 and RSOH OverHead bytes insertion,
provides the data together with control bits on two 16-bit differential LVDS interfaces to EUCLIDE.
B1/B2 Insertion + Scrambler:
it performs errored blocks BIP-8 (B1) and BIP-24 (or BIP-96) (B2) computing and insertion,
scrambling.
FAW Insertion:
it performs frame alignment and word insertion.
O/E TX:
it performs the conversion from an electrical STM-1 (or STM-4) signal to an equivalent optical
stream.
3.4.3.2 Loopbacks
For Test and maintenance purposes Loop-back capabilities, located on FERMAT Fpga, are supported.
For each STM-1 (or STM-4) Channel, FERMAT Fpga provides both "Line" side and "Equipment" side
Loopbacks with VC4 granularity (or 4xVC4 granularity for STM4).
In both "Line side Loopback" and "Equipment side Loopback", the following operating modes are
supported:
• "Loop and continue"
• "Loop and send AIS"
These Loopbacks are controlled via ISPB bus.
Technical Handbook SDH
Units Description
Alcatel 1850 TSS-320 Rel.1.1
8DG 07734 CAAA Edition 01 55/84