Figure 97. Stm-1 Structure And Soh Byte Contents - Alcatel 1850 TSS-320 Technical Handbook

9 COLUMNS (Bytes)
A1
A1
RSOH
B1
D1
B2 B2
D4
MSOH
D7
D10
S1
A1 - A2The six octets of type A1=11110110 and A2=00101000 constitute the alignment word.
J0 Regenerator Section Trace.
B1 This octet resulting from the BIP-8 procedure performed on the previous frame at the
scrambler output, is inserted into the current frame before scrambling; it is utilized to estimate the
BER in the regenerator section.
B2 These three octets, resulting from the BIP-Nx24 encoding performed on the previous
frame without the first three rows of SOH, are inserted into the current frame before scrambling;
they are not estimated again in the repeaters because they are utilized to estimate
between multiplexer.
E1 - E2(orderwire, EOW) Are utilized for service telephone communication between regenerators
(E1) and between muldex and muldex (E2).
D1 ³ D3Are utilized as a 192 Kbit/s channel for data communication (DCC=Data Communication
Channel) between regenerates in the TMN network.
D4 ³ D12Are utilized as a 576 Kbit/s channel for data communication (DCC) between multiplexers
in the TMN network.
F1 (user channel) Is utilized to transmits a data channel received from SERVICE unit (for
service and maintenance).
K1 - K2 Are utilized for APS indications (Automatic Protection Switching); the last three K2 bits
(b6³b8) are used like MS-RDI multiplex section remote indication for FERF and AIS alarms
between the multiplexers.
S1 Indicates synchronization status (b5³b8) of sync. path status.
M1 Indicates MS-REI Far-end Block Errors (FEBE) for the multiplex section.
Notes:
– bytes marked with X are reserved for national use.
– all unmarked bytes are reserved for future international standardization (for media
dependent, additional national use and other purposes).
– bytes marked with D is a Media Dependent byte: not operative.
– bytes marked with ² are not scrambled (like the whole first row).
Alcatel 1850 TSS-320 Rel. 1.1
150/270 8DG 07734 AAAA Edition 01
A1 A2 A2 A2 J0
E1 F1
D2 D3
AU pointer(s)
B2 K1 K2
D5 D6
D8 D9
D11 D12
M1 E2

Figure 97. STM-1 structure and SOH byte contents

261 COLUMNS (bytes)
STM-1
PAYLOAD
Technical Handbook Common
Functional Description
the BER