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

STM-1 FRAME FORMAT

STM-1 SECTION OVERHEADS

ADD-DROP MULTIPLEXERS

Network Structures

SDH Hierarchy (1)

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

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