SDH Principles

SDH Concepts

Features and advantages of SDH

• SDH is apparently synchronous. All the SDH recommendations are based upon the use of a SINGLE reference clock.

• SDH is compatible with existing PDH networks. • SDH provides much simpler extraction and insertion of

any lower- order Tributary stream from a higher-order Tributary stream or frame structure without the need to completely demultiplex

• SDH allows for integrated network management and performance monitoring using centralised network control.

PLESIOCHRONOUS MULTIPLEXING

140

34

34

88

2

34

8

8

2

OFTE

64 X

2Mbit/s

Tribs

8 Mbit/s DDF

2 Mbit/s DDF 34 Mbit/s DDF

140 Mbit/s DDF

(or Radio)

OPTICAL

FIBRE

STM-1 FRAME FORMAT

REGENERATORSECTIONOVERHEAD

MULTIPLEXSECTIONOVERHEAD

ADMINISTRATIVE UNIT (AU) POINTERS

STM-1 PAYLOAD

1 2709

9 ROWS

COLUMNS

STM-1 SECTION OVERHEADS

A1* A1* A1* A2* A2* A2* C1*

B1 E1 F1

D1 D2 D3

B2 B2 B2 K1 K2

D4 D5 D6

D7 D8 D9

D10 D11 D12

S1 Z1 Z1 Z2 Z2 Z2 E2

AU POINTERS

9 BYTES

9

ROWS

RSOH

MSOH

* First ROW of 9 Bytes are not scrambled.

* *

ADD-DROP MULTIPLEXERS

THROUGH CONNECTIONS

TRIBUTARY TO TRIBUTARY CONNECTION

ADD / DROPCONNECTION

ADD / DROPWITH PROTECTION

STM-n

FRAME

STM-n

FRAME

PDH TRIBUTARIES

OR

LOWER ORDER (OR SIMILAR)

STM-n FRAMES

Network Structures

AD-MUX

TRIBS

AD-MUX

TRIBS

AD-MUX

TRIBS

STM - 1 STM - 1

AD-MUX

TRIBS

AD-MUX

TRIBS

AD-MUX

TRIBS

STM - 1 STM - 1

1STM-1

AD-MUX

TRIBS

TERM

MUX

TRIBS

E M

ELEMENT

MANAGER

STM-1

GATEWAY

'Q' INTERFACE

SPUR

W E

W

LOCAL

TERMINAL

LT

RINGMASTER.

EXT. SYNC.

SDH Hierarchy (1)

STM-1 AU-4 VC-4

TU-3

TU-2

TU-12

VC-3

VC-2

VC-12

C-3

C-2

C-12MAPPING

ALIGNING

MULTIPLEXING1.5 Mbit/s

2 Mbit/s

6.3 Mbit/s

45 Mbit/s34 Mbit/s

140 Mbit/s

x4

x3

x7

x3

TU-11 VC-11 C-11

Payload

AU-3 VC-3

x7

x3

C-4

TUG-2

TUG-3

AUG-4

KEY

x1

SDH Hierarchy (2)

STM-256

STM-64

STM-16

STM-4

STM-1

AUG-256

AUG-64

AUG-16

AUG-4

AUG-1

AU-4-64c

AU-4-16c

AU-4-4c

AU-4

AU-3

AU-4-64c

AU-4-16c

AU-4-4c

AU-4

AU-3

C-4-64c

C-4-16c

C-4-4c

x 1

x 1

x 1

x 1

x 1 x 1

x 1

x 1

x 1

x 4

x 4

x 4

x 4

x 3

Pointer Processing

Multiplexing

Aligning

Mapping

Cross connect Structure

Alarms and maintenance

Low Order (LO) Path

Tributary

G703 AIS

LO PTE HO PTE MSTE RSTE MSTE HO PTE LO PTE

High Order (HO) Path

Multiplexer Section

RegeneratorSection

RegeneratorSection

B1 BIP-8 B1 BIP-8

B2 BIP-24

BIP-2

REI/FEBE

RDI/RAI(V5)

REI/FEBE

FEBE/REI(V5)

RAI/RDI

(V5)

RAI/RDI(G1)

REI/FEBE(G1)

RDI/FERF(K2)

LOSLOF(A1/A2)

RDI/RAI(G1)

B3 (BIP-8)

LOP

LOSLOF

AIS

RDI/FERF(K2)

LOP

AIS(H1,H2)

LOP

AIS(V1,V2) AIS

Detection Transmission Generation

MS

Protection Mechanisms

• Network Protections:– MS-SPRING (2/4 fibre);– MSP (1+1 and 1:N);– 1+1 SNCP;– Gigabit Ethernet 1:1 Line Protection.

• Equipment Protections:– Power Supply Protection;– 1+1 Controller/Communication Card Protection;– 1+1 Switch Card Protection;– Fan Protection;– 1:N Tributary Card Protection on STM-1 G.703

tributary interfaces.

THANK YOU