guide to sdh2

Guide to SDH 1

NECITR-YTCYM-OCT/00-02

Guide to SDH2

Guide to SDH

Synchronous Digital Hierarchy

Guide to SDH 2


Guide to SDH2

Contents

• Features of SDH

• SDH Hierarchy

• World-wide Standard

• Synchronous System

• Simple Access to Tributaries

• SDH Multiplexing Structure

• Multiplexing Process

• STM-N Multiplexing

• STM-1 Frame Structure

• Overhead Termination

• Section and Path

• Section Overhead

• Bit Interleaved Parity

• Pointer Functions

Guide to Synchronous Digital Hierarchy

• Scrambling

• Network Synchronization

• Timing Source

• S1 Byte Quality Levels

• Clock Switching Rules

• Timing Source Flow

• SDH Function Model

• Network Management System

• SDH Radio System

• SOH and RFCOH

• SDH Radio Operation Mode

• SDH Radio Function Model

• ITU-T Recommendation

Guide to SDH 3


Guide to SDH2

Features of SDH

• One Global Digital Hierarchy• ITU-T standardization in 1988

• World-wide Standard• Common to Europe, North America and Japan digital hierarchy

• Multi vendor environment

• Unified Multiplexing Structure • Flexible multiplexing structure using virtual container (VC-n)

• Synchronous System• Synchronous multiplexing

• Simple access to tributaries (Add-drop/Cross connect)

• Abundant Overhead Bit• Sophisticated Network Management System

• Full Management Capability for the Network Operator

Guide to SDH 4


Guide to SDH2

SDH Hierarchy

STM-n : Synchronous Transport Module-n (n=1, 4, 16, 64)

125 micro seconds frame speed (based on 8kHz sampling frequency) Byte interleaved multiplexing (one byte = 64kb/s)

155.52 MB/s2,430 bytes (19,440 bits) 125 micro second

STM-4 : 622.08 MB/s9,720 bytes (77,760 bits) 125 micro second

STM-16 : 2,488.32 MB/s38,880 bytes (311,040 bits) 125 micro second

STM-64 : 9,953.280 MB/s155,520 bytes (1,244,160 bits) 125 micro second

STM-0 : 51.84 MB/s810 bytes (6,480 bits) 125 micro second

STM-1

STM- 4

STM-16

STM- 64

STM- 0

ITU-T G.707

Guide to SDH 5


Guide to SDH2

World-wide Standard

CEPT

2.048 MB/s

8.448 MB/s

34.368 MB/s

139.264 Mb/S

USA

1.544 MB/s

6.312 MB/s

44.376 MB/s

274.176 Mb/S

JAPAN

1.544 MB/s

6.312 MB/s

32.064 MB/s

397.72 Mb/S

SDHSTM-1 : 155.52 MB/sSTM-4 : 622.08 MB/sSTM-16: 2488.32 MB/s

STM-64 : 9953.28 MB/s Sub STM-0 : 51.84 MB/s

PDHITU-T G703

SDHITU-T G707

Guide to SDH 6


Guide to SDH2

Synchronous System

• All equipment in the network use the same clock source

• Stuffing is not required for multiplexing

• SDH multiplexing using pointer function• All byte visibility

• Minimize delay of multiplexing

• Minimize memory size

• Simple Access to Tributaries• Direct tributary access to high speed aggregate data

• High stability clock source required• 10 stability clock source for Primary reference source

-11

Guide to SDH 7


Guide to SDH2

Simple Access to Tributaries

2 MBDrop

2 MBInsert

8 MB 8 MB

34 MB

140 MB140 MB

34 MBPDH

Add-Drop Multiplex

2 MBInsert

2 MBDrop

STM-1 STM-1

SDH

Stuff multiplexing

Guide to SDH 8


Guide to SDH2

SDH Multiplexing Structure

C4

C3

C2

C12

C11VC11

VC12

VC2

TU11

TU12

TU2

TU3

139264kb/s

34368kb/s

44736kb/s

6312kb/s

2048kb/s

1544kb/s

TUG2

TUG3 VC3

VC3

VC4AU4

AU3

AUGSTM-N

x N

x 3

x 7

x 7

x 1x 3

x 1

x 3

x 4

: Pointer Processing

: Multiplexing

: Aligning

: Mapping

STM-RR

(STM-0)

Container

Lower OrderVirtual

ContainerTributary

UnitTributary

Unit Group

Higher OrderVirtual

ContainerAdministrative

UnitAdministrative

Unit Group

SynchronousTransport

Module - N

STM for Radio Relay System

Guide to SDH 9


Guide to SDH2

Multiplexing Process (1)

2MB

C-12

VC-12C-12

S

POH

VC-12

VC-12 (1)VC-12 (2)VC-12 (3)PtrPtrPtr

Ptr

(1)(3) (2)

TUG-2 (1)TUG-2 (2)TUG-2 (7)

TU-12

TUG-2

TUG-3

VC-4

AU-4

AUG

STM-N

TUG-3TUG-3 TUG-3POH

VC-4Ptr

AU-4

(1)(2)(3)

AUGAUG (1)(N)SOH

PDH

2MBS : Stuffing bitsPtr : Pointer

(Container-12)

(Virtual Container-12)

(Tributary Unit-12)

(Tributary Unit Group-2)

(Tributary Unit Group-3)


(Administrative Unit-4)

(Administrative Unit Group-4)

(Synchronous Transport Module Level-N)

Example

2MB/s to STM-N

Ptr

: Logical association: Physical association

Unshaded areas are phase aligned, Phase alignment between the unshaded and shaded areas is defined by the pointer(Ptr) and is indicated by the arrow

Guide to SDH 10


Guide to SDH2

Multiplexing Process (2)

140MB

C-4S

C4VC-4

AU-4

AUG

STM-N

POH

VC-4Ptr

AU-4

AUGAUG (1)(N)SOH

PDH

S : Stuffing bitsPtr : Pointer

(Container-4)


(Administrative Unit-4)

(Administrative Unit Group-4)

(Synchronous Transport Module Level-N)

Example

140MB/s to STM-N

140MB

: Logical association: Physical association

Unshaded areas are phase aligned, Phase alignment between the unshaded and shaded areas is defined by the pointer(Ptr) and is indicated by the arrow

Ptr

Guide to SDH 11


Guide to SDH2

STM-N Multiplexing

Byte Interleaved Multiplexing

9 rows

9 x N 261 x N

ABC - - - - NABC - - - - NABC - - - -

NABC - - - - N125μS

RSOH

MSOH

AU POINTER

ABC - - - - NABC - - - - NABC - - - -

STM -1

STM -1

STM -1

STM -1

AAA

BBB

CCC

NNN

AU4

AU4

AU4

AU4

Guide to SDH 12


Guide to SDH2

STM-1 Frame Structure(1)

1 2 3 4 5 6 7 8

8 bits = 1 byte

(1)

(1)

(2)(3)

(9)

270 columns

9 ro

ws

(2) (3) (4) (5) (6) (7) (8) (9)

6.43 nS

ＳＯＨ 9 (bytes) PAYLOAD (261 bytes)

(4)(5)(6)(7)(8)

125 μS

125 μS

9 261

STM-1 : 155.52MB/s125 μS / Frame19,440 bits / Frame1 byte : 64kb/s

Guide to SDH 13


Guide to SDH2

PO

H

STM-1 Frame Structure (2)

9 bytes 261bytes

3

5

1

RSOHPAY LOAD

MSOH

POINTER

PO

H

85 bytes

PO

H

PO

H

VC

12

9 ro

ws

270bytes

VC-3

STM-1 : Synchronous Transport Module Level-1 RSOH : Regenerator Section OverheadMSOH : Multiplex Section OverheadPOH : Path OverheadVC-x : Virtual Container

STM-1155.52 MB/s

125 μS

VC-4

261bytes

Guide to SDH 14


Guide to SDH2

Overhead Termination

RRT RRTMUX MUX

Regenerator Section

Path

Regenerator Section

Multiplex SectionMultiplex Section Multiplex Section

RSOH

MSOH

POH

RRR

Regenerator Section Overhead

Multiplex Section Overhead

Path Overhead

RRT RRT

RSOHTermination

MSOHTermination

RRR MUXMUX

POHTermination VC VC

Virtual Container

MST MST RST MST MST

Guide to SDH 15


Guide to SDH2

Section and Path(1)

C-1,2

C-3,4

VC-1,2

VC-3,4 STM-NC-1,2

C-3,4

VC-1,2

VC-3,4STM-N

RSOH RSOH RSOH

MSOH

VC-3,4 POH

VC-1,2 POH

RSOH : Regenerator Section Overhead

MSOH : Multiplex Section Overhead

Lower Order Path Overhead (VC-1/VC-2 POH)

Higher Order Path Overhead (VC-3/VC-4 POH)

SOH

VC POH

Type of Overhead

Multiplex Equipment Multiplex Equipment

Guide to SDH 16


Guide to SDH2

Section and Path (2)

RT

RR

RT

RT

RT

RR RT RT

MUX MUX

MUX

RT RT

MUX

RT RT

MUX

RT

RT

MUX RT RT MUX

RS RS

MS

RS RS

MS

VC4 VC3

VC4

VC3

VC2

VC2VC2

VC2

Path

Path

Path

RT : Radio TerminalRR : Radio RepeaterRS : Regenerator SectionMS : Multiplex SectionVCx : Virtual Container

Path

Guide to SDH 17


Guide to SDH2

Section Overhead (1)

A1,A2 : Frame Alignment

J0 : Regenerator Section Trace

B1 : Bit Interleave Parity for Regenerator Section (BIP-8)

E1 : Order Wire at Regenerators

F1 : User Channel (64kb/s)

D1 - D3 : Data Communication Channel

for Regenerator Section (DCCr) (192kb/s)

B2 : Bit Interleave Parity for Multiplex Section (BIP-24)

K1,K2 : Automatic Protection Switching (APS)

MS-AIS, MS-RDI

D4 - D12 : Data Communication Channel

for Multiplex Section (DCCm) (576kb/s)

S1 : Synchronization Status

Z1,Z2 : Not Defined yet

M1 : Section Status Report

MS-REI / Far End Block Error (FEBE)

E2 : Order Wire at Multiplex Section

X : Reserved for national use

A1 A1 A1 A2 A2 A2 J0

B1

D1

E1 F1

D2 D3

B2 B2 B2 K1 K2

E2S1 M1Z1 Z1 Z2 Z2

AU Pointer(s)

D4 D5 D6

D7 D8 D9

D10 D11 D12

X

X

X

XX

X

REI : Remote Error IndicatorRDI : Remote Defect Indicator

Guide to SDH 18


Guide to SDH2


• A1, A2 : Frame alignment signal• This is a unique identifier indicating start point of STM frame. It is using for Frame synchronization.

Unscrambled. (A1 :11110110 A2 : 00101000)

• J0 : Regenerator section trace • This byte used for the confirmation of correct regenerator section connection. Unscrambled(C1:Former

recommendation)

• B1 : Bit Interleaved Parity - 8• This is an 8 bits error check code using even parity coding. It allows each regenerator section to monitor

and reset this byte. The BIP-8 is computed over all bits of the previous STM-N frame after scrambling and is placed in byte B1 before scrambling.

• B2 : Bit Interleaved Parity -24• This is a 24 bits error check code using even parity coding. Each multiplex section monitor and reset this

bytes. The BIP-24 is computed over all bits except for the first three rows of SOH and is placed in bytes B2 before scrambling.

• E1 : Order wire for regenerator section• It is used to provided for order wire channels for voice communication. E1 is a part of RSOH and may be

accessed at each regenerators. (64kb/s)

• E2 : Order wire for multiplex section• E2 is a part of MSOH and may be accessed at each multiplexer. (64kb/s)

Guide to SDH 19


Guide to SDH2


• F1 : User channel• This byte is reserved for user purposes (for example network operator) (64kb/s)

• D1 - D3 : Data Communication Channel for Regenerator Section (DCCr)• This data channel passes the information between the regenerator sections and the network management

center. This is to provide alarm monitoring, remote maintenance, reconfiguration, etc.(192kb/s)

• D4 - D12 : Data Communication Channel for Multiplex Section (DCCm)

• This is the data communication channel for the multiplex sections.(576kb/s)

• K1, K2 : APS Channel (Automatic Protection Switching)• These are control bytes for any automatic protection switching that will be used on the network. The state

of these bytes tells the network protection equipment which route to transmit on.

• A part of K2 is also used to send the MS-RDI (Multiplex Section Remote Defect Indication/Formerly FERF, Far End Receive Failure) and MS-AIS (Multiplex Section Alarm Indication Signal).

• S1 : Synchronization Status• This byte indicates quality of synchronization reference clock source used by the equipment.

• M1 : Section Status Reporting• The result of BIT-24 (B2) is reported to its originating end by this byte as MS-REI (Multiplex Section

Remote Error Indication) Formerly FEBE (Far End Block Error).

• Z1, Z2 : Spare

Guide to SDH 20


Guide to SDH2

Bit Interleaved Parity (1)

RSOH

MSOH

PAYLOADPtr

B1

MSOH

PAYLOADPtr

Result of BIP-8

Frame #n

Frame #n+1

1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

1 2 3 4 5 6 7 81 2 3 4 5 6 7 8

Result of Even ParityEven : K=0Odd : K=1

1 2 3 4 5 6 7 8

1 2 3 4 5 6 7 8

B1 byte

Frame #n

Frame #n+1

B1 byte is monitored and renewed at every regenerator section

BIP-8

Guide to SDH 21


Guide to SDH2


RSOH

MSOH

PAYLOADPtr

B2

MSOH

PAYLOADPtr

Result of BIP-24

Frame #n

Frame #n+1

1 2

Result of Even ParityEven : K=0Odd : K=1

B2 byte

Frame #n

Frame #n+1

2423 1 2 2423

1 2 23 24

1 2 23 241 2 23 24

1 2 23 24

B2 bytes are monitored and renewed at every multiplex section

RSOH

RSOH

BIP-8

Guide to SDH 22


Guide to SDH2


Multiplex Section

Regenerator SectionRegenerator Section Regenerator Section

BIP-8 BIP-8 BIP-8

BIP-24

B1 B1 B1B1

B2 B2

B1 B1

: Generate

: Detect

Radio Terminal Radio TerminalRadio Repeater Radio Repeater

B3/V5

Multiplex

B3/V5

Multiplex

BIP-8/BIP-2

Path

Guide to SDH 23


Guide to SDH2

Pointer Function (1)

POINTERSOH SOH

Aμs

VC4 n Frame

STM-1 n Frame

STM-1 n+1 Frame

VC4 n Frame

STM-0 n Frame

STM-0 n+1 Frame

Aμs

p q

q = p +

VC4 VC4

STM-1 Frame

VC-4 Frame (in phase)

VC-4 Frame (lagging)

(1) VC-4 Frame (in phase)

(2) VC-4 Frame (lagging)

(1)

(2) VC4

Phase Alignment

VC4

Guide to SDH 24


Guide to SDH2


Bμs

B μs

Reference Frame timingof receiving station

q

r = q +

VC4

r

VC4

Pointer valuenot changed

Reference Frame timingof receiving station

VC4

p

VC4

pIn coming STM frame is the same as reference frame timing of the station

Poi

nte

r p

roce

ssin

g

In coming STM frame is lagging to the reference frame timing of the receiving station

Pointer valuechanged

B μs

Poi

nte

r p

roce

ssin

g

Case 1 Case 2

Phase Alignment

Guide to SDH 25


Guide to SDH2


ST

M-0

n

Fra

me

ST

M-0

n+

1 F

ram

e

STM-0 Pay loadClock : f 0

(1) Clock : f 0

783 bytes (reference)

STM-0 Pay loadClock : f 0

783 bytes

STM-0 Pay loadClock : f 1 < f 0

782 bytes

STM-0 Pay loadClock : f 2 > f 0

784 bytes

ST

M-0

n

Fra

me

ST

M-0

n+

1 F

ram

e

(2) Clock : f 1 < f 0

Positive Justification

ST

M-0

n

Fra

me

ST

M-0

n+

1 F

ram

e

(2) Clock : f 2 > f 0

Negative JustificationSupposedPointer value = 0

(1)

(2)

(3)

VC3783 bytes

VC3782 bytes

VC3784 byte

Frequency Justification

Guide to SDH 26


Guide to SDH2


p

P + 1

VC4

p

VC4

In coming STM clock frequency is lower than the reference clock frequency of the receiving station.

Frame timing is the same as reference frame of the station.

Reference clockf 0

PointerProcessing

Circuit

In coming STM clockf 1

f 1 < f 0

Poi

nte

r Ju

stifi

catio

n

Frequency Justification

Pointer value incremented by “1”. Positive justification.

Guide to SDH 27


Guide to SDH2

Scrambling

RSOH

MSOH

Payload

1000000100000110

1100000010000011

1110000001000001

1111000000100000

1111100000010000

1111110000001000

1111111000000100

a b c d e f g

0

000000100000110

x

1

3

2

456789

101112

1270 1 1 1 1 1 1 1

1 1 1 1 1 1 1 0

D

C

Q

S

D

C

Q

S

D

C

Q

S

D

C

Q

S

D

C

Q

S

D

C

Q

S

D

C

Q

S

+

+

Data in

Scrambleddata out

STM-N clock

Frame pulse

x a b c d e f g

1

32

456789

A1,A2 1 1 1 1 1 1 1 0 0 0 0 0 0 1

No scramble Start scramble

RSOH

MSOH

Payload

1

32

456789

A1,A2 1 1 1 1 1 1 1 0 0 0 0 0 0 1

Generator Polynomial = 1 + X + X6 7

Scramble pattern length = 2 -1 =127 bits7

Guide to SDH 28


Guide to SDH2

Network Synchronization (1)

Equipment

#1

Equipment

#2

Equipment

#3

Clock : Fa

Station A

All the equipment in the station-A operate by the master clock (FA)

Station B

Station C

Station A

Fa

FcFb

Other station’s data can not be read unless clock synchronization

Fa = Fb = Fc

Networking

Network Synchronization

Station C

Station D

Station E

Station A

Station B

F0

All the network element work in the same clock (F0)

Byte visibility at all bit rate

Synchronous multiplexing

Cross connect

Direct tributary access from high speed bearer

Simple multiplex configuration

Merit of the Network Synchronization

Guide to SDH 29


Guide to SDH2

Network Synchronization (2)

FaTX RX

Clk extraction

RXFb

TX

Clk extractionTransmission line

Asynchronous timing

Station A Station B

Fa

TX RX

RX TX

Clk extractionTransmission line

Loop timing

Station A Station B

TX RX

RX TX

Transmission line

Network synchronization timingStation A Station B

F0 F0

Master clock

Guide to SDH 30


Guide to SDH2

Timing Source

REG1 MUX CLK

REG1 MUX CLK

REG1 MUX CLK

REG1 MUX CLK

REG1 MUX CLK

REG1 MUX CLK

REG1 MUX CLK

SEL

SEL

REG1 MUX CLK

INT

SELTiming Source

CLK module

EXT CLK : Incoming signal from external reference 2.048MHz clock signal or 2.048/1.544MB/s Bipolar signal.

MUX CLK : Clock extracted from incoming STM-1 data stream (from MUX equipment)

DMR CLK : Clock demodulated by the demodulator from STM-1 data stream coming from the far-end radio station

INT CLK : Clock produced by the internal oscillator in the CLK module

Note; only for MST mode

Guide to SDH 31


Guide to SDH2

S1 Byte Quality Levels

S1 byte pattern Quality Level

S1 Byte Valueb5 b6 b7 b8

0 0 0 0

0 0 1 0

0 1 0 0

1 0 0 0

1 0 1 1

1 1 1 1

0

2

3

4

5

6

Quality Unknown

G.811 (Primary Reference Clock)

G.812 Transit Node (Slave Clock)

G.812 Local Node (Slave Clock)l

SET(Synchronous Equipment Timing Source)

Do not use for synchronization

Clock Type

Quality Level with S1 Byte Pattern

S1 byte is the signal to transmit QUALITY LEVEL of timing signal to all continually connected NEs.

The value of QUALITY LEVEL is transmitted by low 4-bit of MSOH S1 byte.

Guide to SDH 32


Guide to SDH2

Clock Switching Rules

1. Select the highest quality clock.

2. Select the highest priority for the same quality clock sources.

3. Consider the clock from a failed line signal to be Q=6. 4. Backward direction S1 byte is set to Q=6

DMR CLK : Q=3MUX CLK : Q=2

Select MUX Clock DMR CLK : Q=2MUX CLK : Q=2

Select DMR Clock

MUX CLK : Priority=2DMR CLK : Priority=1

DMR CLK : Q=2MUX CLK : Q=2

Select MUX Clock

MUX CLK : Priority=1DMR CLK : Priority=2

xQ=6

DMR CLK : Q=2

MUX CLK : Q=2

Select MUX Clock

Backward S1 : Q=6

Guide to SDH 33


Guide to SDH2

Timing Source Flow (1)

Ext timing

NE1EXT CLK

NE2MUX CLK

NE4MUX CLK

NE3DMR CLK

NE7MUX CLK

NE8DMR CLK

NE6MUX CLK

NE5DMR CLK

Q=6Q=2

Q=6Q=2

Q=2

Q=6

Q=6Q=2

Q=2

Q=2

Q=6Q=2

Q=2

Q=6

Q=2 Q=6

Timing Source Flow in Normal State

NE TIMING SOURCE

NE1 EXT: QTY=2, PRTY=1 <--SEL INT : QTY=5, PRTY=2

NE2 MUX : QTY=2, PRTY=1 <--SEL DMR : QTY=6, PRTY=2 INT : QTY=5, PRTY=3

NE3 MUX : QTY=6, PRTY=2 DMR : QTY=2, PRTY=1 <--SEL INT : QTY=5, PRTY=3






Guide to SDH 34


Guide to SDH2


NE TIMING SOURCE



NE3 MUX : QTY=6, PRTY=2 DMR : FAIL , PRTY=1 INT : QTY=5, PRTY=3<--SEL






Ext timing

NE1EXT CLK

NE2MUX CLK

NE4MUX CLKNE7

MUX CLK

NE8DMR CLK

NE6MUX CLK

NE5DMR CLK

Q=6Q=2 -->5

Q=6 --> 5Q=2

Q=2

Q=6

Q=6Q=2Q=2Q=2

Q=6Q=2

Q=2

Q=6

Q=2Q=6

Timing Source Flow in Occurrence of Interruption (1/5)

XNE3DMR CLK -->HOLD OVER --> INT CLKINT

Guide to SDH 35


Guide to SDH2


NE TIMING SOURCE



NE3 MUX : QTY=6, PRTY=2 DMR : QTY=6, PRTY=1 INT : QTY=5, PRTY=3 <--SEL






Ext timing

NE1EXT CLK

NE2MUX CLK

NE4MUX CLK

NE3INT CLK

NE7MUX CLK

NE8DMR CLK

NE6MUX CLK

NE5DMR CLK

Q=6Q=5

Q=5Q=2

Q=2

Q=6

Q=6Q=5Q=2

Q=2

Q=6Q=2

Q=6

Q=2 --> 5

Q=6Q=2


X

INT

Guide to SDH 36


Guide to SDH2


NE TIMING SOURCE









Ext timing

NE1EXT CLK

NE2MUX CLK

NE4MUX CLK

NE3INT CLK

NE7MUX CLK

NE8DMR CLK

NE6MUX CLK --> DMR CLK

NE5DMR CLK


X

NE5DMR CLK

Q=5Q=2

Q=2

Q=6

Q=6Q=5

Q=2 --> 6

Q=2

Q=6Q=2

Q=2

Q=5

Q=6Q=2Q=6Q=5

INT

Guide to SDH 37


Guide to SDH2


NE TIMING SOURCE








NE8 MUX : QTY=6, PRTY=2 DMR : QTY=2, PRTY=1 <--SEL INT : QTY=5, PRTY=3Timing Source Flow in Occurrence of Interruption (4/5)

Ext timing

NE1EXT CLK

NE2MUX CLK

NE4DMR CLK

NE3INT CLK

NE7MUX CLK

NE8DMR CLK

NE6DMR CLK

X

NE5DMR CLK --> MUX CLK

Q=5Q=2

Q=2

Q=6

Q=6 --> 2Q=5Q=6Q=2

Q=6Q=2

Q=2

Q=5 --> 6

Q=6Q=2Q=6 --> 2Q=5

INT

Guide to SDH 38


Guide to SDH2


NE TIMING SOURCE








NE8 MUX : QTY=6, PRTY=2 DMR : QTY=2, PRTY=1 <--SEL INT : QTY=5, PRTY=3Timing Source Flow in Occurrence of Interruption (5/5)

Ext timing

NE1EXT CLK

NE2MUX CLK

NE4DMR CLK

NE3INT CLK -> MUX CLK

NE7MUX CLK

NE8DMR CLK

NE6DMR CLK

X

NE5MUX CLK

Q=5 --> 2Q=2

Q=2

Q=6

Q=2Q=6Q=6Q=2

Q=6Q=2

Q=2

Q=6

Q=6Q=2Q=2Q=5 --> 6

INT X

Guide to SDH 39


Guide to SDH2

SDH Function model (1)

PPILPA

-m

LPT

-m

LPC

-m

HPA

-m/n

HPT

-n

HPC

-nMSA MSP MST RST SPI

PPILPA

-n

ABCDEFGHJKLM

M

S11 S10

S11 S10 S9 S8 S7 S6 S5 S4 S14 S3 S2 S1

Synchronous equipment management function

SEMF

Multiplexer timing source

MTS

Multiplexer timing

physical interface

MTPI

Message communications

functions

MCF

S11 S8 S7 S6 S5 S4 S3 S2 S1S10 S9

S12

S13

S14

S15

P

N

D4-D12 (DCCm)

D1-D3 (DCCr)

STM-N

port

S12

Synchronisation

interface port

T3

T1T0T2

V

Q Interface port

F Interface port

n=3 or 4

Ple

sioc

hron

ous

trib

utar

y po

rt

Overhead access

OHA

U1 E1, F1 unused bytes in RSOH

E2, Z1, Z2, D4-D12 unused bytes in MSOH

U2U3U4

F2, Z3, Z4, Z5

Lower order path functions; m=1,2,or 3 Higher order path functions; n = 3,4 Transport terminal functions

OHA interface

MSA:Multiplex Section Adaptation

HPC-n:Higher Order Path Connection

HPT-n:Higher Order Path Termination

HPA-m/n:Higher Order Path Adaptation

LPC-m:Lower Order Path Connection

LPT-m:Lower Order Path Termination

LPA-m:Lower Order Path Adaptation

PI: Plesiochronous Physical Interface

SPI:SDH Physical Interface

RST:Regenerator Section Termination

MST:Multiplex Section Termination

MSP:Multiplex Section Protection

S13

NP

ITU-T G.783

Guide to SDH 40


Guide to SDH2

SDH Function Model (2)

• SPI : SDH Physical Interface• STM-N signal input/output (Optical / Electrical)

• Timing Extraction from Line signal

• RST : Regenerator Section Termination• Frame Synchronization (A1, A2)

• Scramble / Descramble

• RSOH Termination / Insertion

• B1 error monitoring (BIP-8)

• MST : Multiplex Section Termination• MSOH Termination / Insertion

• B2 error monitoring (BIP-24)

• SD (Signal Degrade), E-BER (Excessive BER) detection and reporting to SEMF

• MS-FERF (MS-RDI) detection and reporting to SEMF

• MSP : Multiplex Section Protection• Protection for the STM-N signal against channel-associated failures within a multiplex section (K1,K2)

• Switching is initiated by SD (Signal Degrade) and SF (Signal Fail)

• MSA : Multiplex Section Adaptation• Adaptation of higher order paths into administrative units (AUs)

• Assembly and De-assembly of AU Groups

• Pointer Generation, Interpretation and Processing

Guide to SDH 41


Guide to SDH2


• HPC : Higher Order Path Connection• Add/Drop, Cross-connect function of higher order VCs

• Port assignment to be made according to the connection matrix (CM) from SEMF

• HPT : Higher Order Path Termination• POH termination and Insertion (VC-n POH, n=3, 4)

• Error monitoring (BIP-8)

• HPA : Higher Order Path Adaptation• TU pointer processing (Pointer generation, Pointer interpretation, Frequency justification)

• LPC : Lower Order Path Connection• Add-Drop, Cross-connect function of lower order VCs

• Port assignment to be made according to the connection matrix (CM) from SEMF

• LPT : Lower Order Path Termination• POH termination and Insertion (VC-n POH, n=1, 2, or 3)

• Error monitoring (BIP-8)

• LPA : Lower Order Path Adaptation• User data (PDH) is mapped into synchronous container (C)

• PPI : Plesiochronous Physical Interface• PDH physical interface

• Timing extraction from the received tributary signal.

• Loss of signal (LOS) detection

Guide to SDH 42


Guide to SDH2


• OHA : Overhead Access• Overhead information interface (RSOH, MSOH, POH)

• MTPI : Multiplexer Timing Physical Interface• External synchronization signal source interface

• MTS : Multiplexer Timing Source• Synchronization source selection

• Internal Oscillator

• SEMF : Synchronouse Equipment Management Function• This interacts with the other functional blocks by exchanging information across the Sn interface.

• Collects all event of the NE– Error monitoring (B1, B2, B3, V5 ...)– Pointer activity (AU justification event, TU justification event)– Loss of Signal, Loss of Frame, Loss of Pointer, MS-AIS, Path AIS, etc

• MCF : Message Communications Function • Interface provided for network management systems

Guide to SDH 43


Guide to SDH2

Network Management System(1)

• Abundant built-in overhead bits realize highly advanced Network Management System

– Overhead bit rate PDH : 0.5% SDH:10%

• Fault Management• Network alarm monitoring

• NE (Network Element) status monitoring

• Event history

• Event filtering

• Performance Management • Performance data display

• Scheduled performance data retrieval from NE

• Quality of Service(QOS) Monitoring

• Quality of Service Threshold setting

Guide to SDH 44


Guide to SDH2

Network Management System (2)

• Configuration Management• Building of overall network view

• Provisioning of network element

• Protection switch

• Path management

• Maintenance Function

• House keeping alarms and control

• Security Management• User registration

• Assignment of user privilege

• Logging of security relevant actions

Guide to SDH 45


Guide to SDH2

Network Management System (3)

Network Management System

SNC-P

DCN

RT

F

F

RR

RR

RT

RT M

RT

RT

RTRT

RT

M

M

M M

RT

RT

F

F F

M

F F

RR : Radio TerminalRR : Radio RepeaterM : Multiplex F : Fots

LCT

LCT

System Configuration Example

Guide to SDH 46


Guide to SDH2

SDH Radio System

DPU MOD TX TX DEM DPU

DPU MOD TX TX DEM DPUSTM INTFC STM INTFC

PDH Radio System

SDH Radio System

RFCOH

PDH signal

2MB/s 4MB/s 8MB/s 34MB/s140MB/s

SDH signal

155MB/s (140MB/s) ( 2MB/s)

RFCOH

PDH data

RFCOH (Radio Frame Complementary Overhead)

Radio frame structure

RFCOH RFCOH

RFCOH (Radio Frame Complementary Overhead)

Radio frame structure

RSOHMSOH

RSOHMSOH

STM-1 frame structure STM-1 frame structure

PayloadRSOH

MSOHPayload

RSOH

MSOHPayload

RSOH

MSOH

PDH data PDH data

Radio Frame Alignment bit / Forward Error Correction bitParity Check bit / Auxiliary Channel bitRadio System Control bit / etc.

Guide to SDH 47


Guide to SDH2

SOH and RFCOH

RRT RRTMUX MUX

Regenerator Section

Path

Regenerator Section

Multiplex SectionMultiplex Section Multiplex Section

RSOH

MSOH

POH

Radio Relay Section Radio Relay SectionRFCOH

RRR

Radio Frame Complementary Overhead

Regenerator Section Overhead

Multiplex Section Overhead

Path Overhead

RRT RRT

RSOHTermination

MSOHTermination

RRR MUXMUX

POHTermination VC VC

Virtual Container

RFCOHTermination

Guide to SDH 48


Guide to SDH2

SDH Radio Operation Mode

MST MSASPI RST

RSOH

MST RST MOD TX RX DEM RST MSAMS

TMST SPIRST

RSOHMSOH MSOH MSOHRSOH RSOHMSOH

Reference Timing Reference Timing

MST Mode Terminal

SPI RST

RSOH

RST MOD TX RX DEM RST SPIRST

RSOHRSOH RSOH

RST Mode Terminal

STM-1 frame structure

Payload

RSOH

MSOH

ptr


Payload

RSOH

MSOH

ptr


Payload

RSOH

MSOH

ptr


Payload

RSOH

MSOH

ptr

Guide to SDH 49


Guide to SDH2

SDH Radio Function Model

MST MSA RST

RST

MST MSA

MOD TX

SPI

SPI

RST

RST

MST

MST

MSP

MST MSA

MST MSA

SPI

SPI

RST

RST

MST

MST

MSP

RST

MOD TX

MOD TX

RX DEM

RX DEM

RST

RST

MSAMST

MSP

MST

MSTMSAMS

T

SPI

SPI

RST

RST

RX DEM RST

HL

HL

MSAMST

MSP

MST

MSTMSAMS

T

SPI

SPI

RST

RST

N+1 Protection system(MST mode)

Guide to SDH 50


Guide to SDH2

ITU-T Recommendation• G707 Network Node Interface for the SDH

• This recommendation is a merged revised version of ITU-T Recommendations G.707, G.708 and G.709 in 1993. This gives Bit rate, Frames structures, Formats for mapping and multiplexing PDH and ATM elements, Functionalities of the overheads.

• G.782 Types and General Characteristics of SDH Multiplexing Equipment• This recommendation gives an overview of the function of SDH multiplexing equipment. It describes the

equipment in terms of various functional blocks. (Function reference model)

• G.783 Characteristics of SDH Multiplexing Equipment Functional Blocks• This recommendation defines the interfaces and functions to be supported by the multiplexer types

defined in Recommendation G.782.

• G.957 Optical Interfaces for Equipment and Systems Relating to SDH• This covers optical interface parameter specifications for equipment and systems supporting the SDH.

• G.784 SDH Management

• This addresses management aspects of the SDH, including the control and monitoring functions relevant to SDH network elements. The SDH management sub-network architecture, SDH embedded control channel(ECC) functions, and SDH ECC protocols are specified.

• G.773 Protocol Suits for Q-interfaces for Management of Transmission Systems• This defines the characteristics of protocol for Q-interfaces of transmission systems/Equipments, as

defined in Recommendations M.30 (Principles for a TMN), and G.771 (Q-interfaces protocol selection process for transmission equipment.

• G.774 SDH Management Information Model for the Network Element View• This provides an information model for the SDH. It identifies the TMN object classes required for the

management of SDH network elements.

• G.803 Architecture of Transport Networks Based on the SDH

guide to sdh2

Documents