sdh_all

08.04.23 09:03 The World of Synchronous Networks 1

• Current transmission technologies (PDH)• The Synchronous Digital Hierarchie (SDH)• Bit rates, frame structures and interfaces in SDH• Basic elements of STM-1• SDH network elements• Synchronization architecture in SDH• Monitoring, maintenance and measurements in SDH• International SDH Network standards• Future Trends

Copyright by Stephan Schultz, Wandel & Goltermann GermanyBox 1262, D-72795 Eningen u.A.e-mail: [email protected]://www.wg.com

All rights reserved.No parts of this book may be reproduced by any means, or transmitted, or translated without the written permission of the publisher.

Basics on SDH from STM-1 up to STM-16


Current Transmission Technologies


The Telephone System

LE LE


T1 T2 T3

T4 T5 T6 T7time Audio Signal

Sampler Output

timeT1 T2 T3

T4 T5 T6 T7

Pulse Amplitude Modulated (PAM)

signal

Sampling


+V0 0 0 0 X XXX

0 0 0 1 X XXX

0 0 1 0 X XXX

1 0 0 0 X XXX

1 0 0 1 X XXX

1 0 1 0 X XXX

1 0 1 1 X XXX

1 1 0 0 X XXX

1 1 0 1 X XXX

1 1 1 0 X XXX

1 1 1 1 X XXX

digital codesQuantization

Level

3248648096112

-VIn accordance with

CCITT’s A-law

1/2V1/4V

1/8V

1/16V

1/32V

1/64V

Non-Linear Quantization and Encoding


8bits per sample

x = 64kbit/s8000

samples per sec

PCM Signal Data Rate


Time Division Multiplexing (TDM)


2048 kbit/s2048 kbit/s

64 kbit/s64 kbit/s

x 4

x 30/31x 24

x 3

x 7x 5

x 3

Japan USA Europe

primary rate

2. order

3.

4.

5.


x 3


397200 kbit/s397200 kbit/s

x 4

x 4


139264 kbit/s139264 kbit/s

x 4

564992 kbit/s564992 kbit/s

x 4



274176 kbit/s274176 kbit/s

x 6



x 4

PDH Systems Worldwide


64 kbit/s Data Signals

15 kHzSound ProgramSignals

139264 kbit/s (+/-15ppm)

1

2048 kbit/s (+/-50ppm)

8448 kbit/s (+/-30ppm)

34 368 kbit/s (+/-20ppm)

64 Channel Capacity:64 x 30 = 1920

0.3 to 3.1 kHzAF signals

DSMX34/140

DSMX8/34

DSMX2/8

1

30

DSMX64k/2

1

30

PCMX 30

1

PCMX 30

5

1

30

4

1

4

PDH Multiplex / Demultiplex


2.448 kbit/s frame: 32x8 bit=256 bit in 125µs

encoded voice / data signals encoded voice / data signals

signallinginformation

timeslots0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

2 Mbit/s Frame Structures


Si: Reserved for international useSa4: Non urgent Alarm (0=Alarm)A: Remote alarm (1=urgent Alarm)

Sa4 to Sa8: Spare bits or used for message based data links (point-to-point applications)FAS: Frame alignment signal (0011011)NFAS: Non frame alignment signal


Si 0 0 1 1 0 1 1



timeslots

Si 1 A Sa Sa Sa Sa Sa 4 5 6 7 8

FAS(frames 0,2,4...)

NFAS(frames 1,3,5...) (M)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31



Si: Reserved for international useSa4: Non urgent Alarm (0=Alarm)A: Remote alarm (1=urgent Alarm)Y: Remote MF alarm (1=Alarm)E: CRC error indication (0=Error)

Sa4 to Sa8: Spare bits or used for message based data links (point-to-point applications)FAS: Frame alignment signal (0011011)NFAS: Not frame alignment signal

signallingsubscr. n

signallingsubscr. n+15


Si 0 0 1 1 0 1 1



timeslots




0 0 0 0 x Y x x

a b c d a b c d

MFAS NMFASframe 0

frames 1... 15 & 17...31

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31



2.448 kbit/s Multiframe, ITU-T G.704

fr 15 fr 0 fr 1 fr 2 fr 3 fr 4 fr 5 fr 6 fr 7 fr 8 fr 9 fr 10 fr 11 fr 12 fr 13 fr 14 fr 15

multiframe

sub multiframe 1 sub multiframe 2

Si: Reserved for international useSa4: Non urgent Alarm (0=Alarm)A: Remote alarm (1=urgent Alarm)Y: Remote MF alarm (1=Alarm)

Sa4 to Sa8: Spare bits or used for message based data links (point-to-point applications)FAS: Frame alignment signal (0011011)NFAS: Not frame alignment signal

signallingsubscr. n



Si 0 0 1 1 0 1 1



timeslots




0 0 0 0 x Y x x

a b c d a b c d

MFAS NMFASframe 0

frames 1... 15 & 17...31

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31



2.448 kbit/s Multiframe, ITU-T G.704

fr 15 fr 0 fr 1 fr 2 fr 3 fr 4 fr 5 fr 6 fr 7 fr 8 fr 9 fr 10 fr 11 fr 12 fr 13 fr 14 fr 15

multiframe

sub multiframe 1 sub multiframe 2

Si: Reserved for international useSa4: Non urgent Alarm (0=Alarm)A: Remote alarm (1=urgent Alarm)Y: Remote MF alarm (1=Alarm)E: CRC error indication (0=Error)M: Transmitting CRC multiframe alignment signal ( CRC MFAS: 001011 )Sa4 to Sa8: Spare bits or used for message based data links (point-to-point applications)FAS: Frame alignment signal (0011011)NFAS: Not frame alignment signal

signallingsubscr. n


Si 0 0 1 1 0 1 1




0 0 0 0 x Y x x

a b c d a b c d

MFAS NMFASframe 0

frames 1... 15 & 17...31

Time slot 0 of CRC multiframe:

sub

mul

tifra

me

1su

b m

ultif

ram

e 2




timeslots0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

0 FAS C1 0 0 1 1 0 1 1

C4 0 0 1 1 0 1 1

C1 0 0 1 1 0 1 1

C4 0 0 1 1 0 1 1

0 1 A Sa Sa Sa Sa Sa



E2 1 A Sa Sa Sa Sa Sa

1 NFAS

6 FAS

7 NFAS

8 FAS

9 NFAS

14 FAS

15 NFAS

256 X 8 bit = 2048 bit

256 X 8 bit = 2048 bit

2 Mbit/s Frame Structures2 Mbit/s Frame Structures


1c 2c 3c 4c s1 s2 s3 s4

1 1 1 1 0 1 0 0 0 0 A N

1a 2a 3a 4a 1b 2b 3b 4b

8.448 kbit/s; frame length 848 bit; 100.4 us; ITU-T G.742

A: Alarm BitN: National Spare Bit1a: Stuffing Control BitS: Stuffing Bit

10 200 208 208 2042 4 4 4 4

Plesiochronous Hierarchies - Frame Structures


1c 2c 3c 4c s1 s2 s3 s4

1 1 1 1 0 1 0 0 0 0 A N

1a 2a 3a 4a 1b 2b 3b 4b



1 1 1 1 0 1 0 0 0 0 A N

A: Alarm BitN: National Spare Bit1a: Stuffing Control BitS: Stuffing Bit

10 200 208 208 2042 4 4 4 4

10 372 380 380 3762 4 4 4 4

1c 2c 3c 4c s1 s2 s3 s4 1a 2a 3a 4a 1b 2b 3b 4b



139.264 kbit/s; frame length 2928 bit; 21 us; ITU-T G.751

A: Alarm BitN: National Spare Bit1a,b,c,d: Stuffing Control BitS: Stuffing Bit

1a 2a 3a 4a 1c 2c 3c 4c 1d 2d 3d 4d1b 2b 3b 4b 1e 2e 3e 4e s1 s2 s3 s4

1 1 1 1 1 0 1 0 0 0 0 0 A N N N

12 472 484 484 4844 4 4 4 4844 48044



AISPDHEquipment

AISPDHEquipment

LOSLOFAIS

D-Bit

BER 10-3

D-Bit

BER 10-6

N-Bit

PDH Maintenance Signals


OLTU

34 - 140

8 - 34

2 - 8

OLTU

34 - 140

8 - 34

2 - 8

OLTU

34 - 140

8 - 34

2 - 8

OLTU

34 - 140

8 - 34

2 - 8

main

stand-by

140 Mbit/s 140 Mbit/s

Line Terminating Unit

Line Terminating Unit

Drop & Insert Station

1,2 ................. 64 1,2 ................. 64

Plesiochronous Drop & Insert


The Synchronous Digital Hierarchy (SDH)


Simpler multiplexing(low SDH level can be directly identified from higher SDH level)

Simple D&I of traffic channels(direct access to lower level systems without synchronization)

Allows mixing of ANSI and ETSI PDH systems

SDH is open for new applications (It can carry PDH, ATM, HDTV, MAN,...)

SDH provides TMN (ECCs)(for centralized network control)

Why SDH


2Mbit/s 34Mbit/s 140Mbit/s STM-1 STM-4

STM-1 / STS-3c Gateway to SONET

TM

DXC

ADMADM ATMSwitch

STM-4/-162Mbit/s

34Mbit/s

140Mbit/s

STM-1

LAN

2Mbit/s

ADM

STM-1

STM-1, STM-4

2Mbit/s

8Mbit/s34Mbit/s

140Mbit/s

ADM : Add Drop MultiplexerDXC : Digital Cross ConnectTM : Terminal MultiplexerDSC: Digital Switching CenterLAN: Local Area Network

DSC

Synchronous Network Structure


VC-2VC-1

VC-2VC-1

VC-4VC-3VC-12

VC-4VC-3

VC-2VC-1

VC-4 VC-3 VC-12

VC-4VC-3

Reg

S M

X

S M

X

MultiplexSection

Regenerator Sections

Higher Order Path

Lower Order Path

STM-nRSOH

STM-nRSOH

STM-n MSOH

VC-4/3 POH

VC-1/2/3 POH

Path Denominations


MU

X /

DE

MU

X

MU

X /

DE

MU

XPDH PDHSDH SDH SDH

Reg.

CC

NNI NNI NNI

ITU-T Rec.:G.707 BitratesG.708 Signal Structure (NNI)G.709 Synchronous Multiplex StructureG.703 Electrical characteristicG.957 Optical interface characteristic

The Network Node Interface (NNI) specifications are necessary to enable interconnection of synchronous digital network elements for transport of payloads

Network Node Interface (NNI)


Bit Rates, Frame Structure and Interfaces in SDH


RSOH: Regenerator section overheadMSOH: Multiplex section overheadPayload: Area for information transport

Transport capacity of one Byte: 64 kbit/sFrame capacity: 270 x 9 x 8 x 8000 = 155.520 Mbit/sFrame repetition time: 125 µs

1

3

5

9

4

270

270 Columns (Bytes)

1 9transmitrow by row

RSOH

MSOH

AU Pointer Payload(transport capacity)

STM-1 Frame Structure


C-4C-4



VC-4VC-4

C-4C-4

VC

-4 P

OH

VC

-4 P

OH



AU PointerAU Pointer

AU-4AU-4

VC-4VC-4

C-4C-4

VC

-4 P

OH

VC

-4 P

OH



1

3

5

9

4

270

270 Columns (Bytes)

1 9

RSOHRSOH AU-4AU-4

MSOHMSOH

AU PointerAU PointerVC-4VC-4

VC

-4 P

OH

VC

-4 P

OH

C-4C-4



12341234123412 . . . .

11111

22222

33333

44444

STM-1 #1

STM-1 #2

STM-1 #3

STM-1 #4

STM-4

The STM-4/16 bit rate is obtained by byte-interleaved multiplexing of the STM-1 tributary signals.

Clock offset at the tributary side is taken into consideration by pointer adaptation on the STM-n output signal.

B1B2

B1B2

termination new

Higher SDH Bitrates


STM-4 SOH

A1 A1 A1 A1 A1 A1 A1 A1 A1 A1 A1 A1 A2 A2 A2 A2 A2 A2 A2 A2 A2 A2 A2 A2 J0 Z0 Z0 Z0 X X X X X X X X

B1 E1 F1 X X X X X X X X X X X X

D1 D2 D3 X

D4

B2 B2 B2 B2 B2 B2 B2 B2 B2 B2 B2 B2 K1 K2

D7

D10

S1Z1 Z1 Z1 Z1 Z1 Z1 Z1 Z1 Z1 Z1 Z1 Z2 Z2 M1 Z2 Z2 Z2 Z2 Z2 Z2 Z2 Z2 E2 E2 X X X X X X X X X X X

D5

D8

D11

D12

D9

D5

36 bytes

B1 and B2 bytes are being recalculatedBytes E1, F1, K1, K2, D1 to D3 and D4 to D12 are taken from tributary #1

A U Pointers

Payload

#1 #2 #3 #4 #1 #2 #3 #4 #1 #2 #3 #4 #1 #2 #3 #4 #1 #2 #3 #4 #1 #2 #3 #4 #1 #2 #3 #4 #1 #2 #3 #4 #1 #2 #3 #4



Basic Elements of STM-1


MU

X /

DE

MU

X

MU

X /

DE

MU

X

back-up line

PDH PDHSDH SDH SDH

Multiplex Section Multiplex Section

Regenerator Section Regenerator Section

Reg.

CC

clock

clock

clock

B1 B1

B3

B2B2

P a t h

Parity Bytes

F2 E1, F1, D1 ... D3E2, D4 ... D12

Comm.Channels

Synchronous Network


J1B3C2G1F2H4F3K3N1

V5J2N2K4

AU - PTR

VC-3/4 POH

VC-11/12/ 2 POH

STM-1 SOH

Media dependent bytesX Reserved for national use

SOH: Section overheadPOH: Path overhead

The overheads (SOH, POH) are used for maintenance and supervision of the SDH transmission network.

RSOH

MSOH Payload

P

O

H

Pointer

A1 A1 A1 A2 A2 A2 J0 X X

D1 D2 D3

B2 B2 B2 K1 K2D4 D5 D6 D7 D8 D9

D10 D11 D12 S1 Z1 Z1 Z2 Z2 M 1 E2 X X

B1 E1 F1 X X

H1 Y Y H2 1 1 H3 H3 H3

Embedded Overhead Bytes


Parity check(B1 calculated by regenerator and multiplexers)

Data communication channels(D1...D3, F1 between regenerators)

Voice communication channels(E1 between regenerators)

Frame Alignment(A1, A2)

Section Trace(J0 Identfication of regenerator source)

A1 A1 A1 A2 A2 A2 J0

B1 E1 F1

D1 D2 D3

B2 B2 B2 K1 K2

D4 D5 D6

D7 D8 D9

D10 D11 D12

S1 M1 E2

AU - Pointer

Functions of Regenerator Section Overhead


Parity check (B2)

Alarm information (K2)

Remote error indication (M1,K2)

Automatic protection switching(K1, K2 Bytes)

Data communication channels(D4 to D12 between multiplexers)

Clock source information (S1)

Voice communications channels(E2 between multiplexers)

A1 A1 A1 A2 A2 A2 J0

B1 E1 F1

D1 D2 D3

B2 B2 B2 K1 K2

D4 D5 D6

D7 D8 D9

D10 D11 D12

S1 M1 E2

AU - Pointer

Functions of Multiplexer Section Overhead


Parity check B3, V5/ BIP-2 calculated by path terminating point

Alarm and performance information (V5, G1)

Structure of the VC Signal label C2

Multiframe indication for TUs (H4)

User communications channelbetween path elements (F2, F3)

Identification of the Path Source (Path Trace J1, J2)

J1B3C2G1F2H4F3K4N1

V5J2N2K4

VC-3/4 POH

VC-11/12/2 POH

Functions of Path Overhead


The Container (C) Basic packaging unit for tributary signals (PDH) Synchronous to the STM-1 Bitrate adaptation is done via a positive stuffing procedure Adaptation of synchronous tributaries by fixed stuffing bits Bit by bit stuffing

The Virtual Container (VC) Formation of the Container by adding of a POH (Path Overhead) Transport as a unit through the network (SDH) A VC containing several VCs has also a pointer area

Functions and Characteristics of the Individual Elements of the NNI


The Tributary Unit (TU) Is formed via adding a pointer to the VC

The Tributary Unit Group (TUG) Combines several TUs for a new VC

The Administrative Unit (AU) Is shaped if a pointer is allocated to the VC formed at last

The Syncronous Transport Module Level 1 (STM-1) Formed by adding a Section Overhead (SOH) to AUs Clock justification through positive-zero-negative stuffing in the AU

pointer area byte by byte stuffing

Functions and Characteristics of the Individual Elements of the NNI


A1, A2 Frame synchronisationB1, B2 Parity bytes for transmission error monitoringJ0 Regenerator section trace D1... D3 Regenerator section DCCD4.. D12 Multiplex section DCCE1, E2 Orderwire for voice communicationF1 User channel for maintenance purposes (data, voice)K1, K2 Automatic protection switching (APS)S1 Synchronisation status messageM1 MS-REI (remote error idication)

J1 Higher order path traceB3 Path parity byte for error monitoringC2 Signal Label (composition of payload)G1 Path status and performanceF2, F3 Path user channelsH4 Payload specific byteK3 Automatic protection switching (APS)N1 Network operator byte (Tandem Connection Monit.)

V5 Error check, path status, signal labelJ2 Lower order path traceN2 Network operator byte (Tandem Connection Monit.)K4 Automatic protection switching (APS)

SOH

VC-3/4POH

VC-1/2POH

Overhead Byte Functionality


ContainerContainer

Virtual ContainerVirtual Container

Administrative UnitAdministrative Unit

Synchronous Transport ModuleSynchronous Transport Module

Path Overhead

Pointer

Section Overhead

Plesiochronous signal 140Mbit/s

C4

VC-4

AU-4

STM-1

The way of integrating PDH signals into STM-1


The pointer technology provides a means to accommodate timing differences at SDH networks.The pointer indicates the start of the payload within a STM-1frame.

AU-Pointer

1

9

TU-PTR

VC

-4 P

OH

VC-12POH

VC-12

VC-4

STM-1

Pointers


H1 Y Y H2 1 1 H3 H3 H3

Opportunity fornegative stuffing(more capacity)

Pointerinc/decIDIDIDID

NDF,mapping struc,pointer inc/dec

J1

C4 payload

N N N N S S I D I D I D I D I D

H1 byte H2 byte

0 1 1 0 1 0 0 1 1 0 0 1 X X X X X X X X X X X X X X X X X X X X 1 0 0 1 S S 1 1 1 1 1 0 0 0 0 0

Opportunity forpositive stuffing(less capacity)

Pointer interpretation :

New data flag (NDF) disabled :New data flag enabled :AU/TU type AU-4/TU-3 :AU/TU type AU-3/TU-3 :AU-4 pointer 0...782 :TU-3 pointer 0...764 :Null pointer indication (NPI) :

Use of the AU-4 Pointer Area, Coding


Frequency justification of several STM-1 signals running into a network node (Pointer Stuffing)

RSOH

MSOH

H1 H2 H3

RSOH

MSOH

H1 H2 H3

1 9 270

RSOH

MSOH

H1 H2

RSOH

MSOH

H1 H2 H3

125µs

250µs

375µs

500µs

Start of VC-4

negative justification byte (data)

Pointer with inverted D bits

New pointer

Actual pointer

Not Synchronous SDH Networks


AU Pointer

RSOH

MSOH

9 261

J1B3C2G1F2H4Z3K3Z5

20 x 13 bytes per row

C-4140 Mbit/s

260

C-4 transport capacity: 260 x 9 x 64 kbit/s = 149.760 kbit/s

Container C-4 contains a 140 Mbit/s PDH Tributary

Mapping 140 Mbit/s


W = I I I I I I I I Y = RRRRRRRR X = CRRRROOO Z = I I I I I I SR

I = Information bitS = Justification opportunity bit

R = Fixed stuffing bitC = Justification control bit

O = Overhead bit

The figure shows one row of the VC-4

96 IW 96 IY96 IY96 IY96 IX

96 IX 96 IX96 IY96 IY96 IY

96 IY 96 IY96 IX96 IY96 IY

96 IY 96 IZ96 IY96 IX96 IY

J1

Mapping of a 140 Mbit/s Tributary into VC-4


AU Pointer

RSOH

MSOH

J1B3C2G1F2H4Z3K3Z5

H1 H1 H1 H2 H2 H2

H3 H3 H3

260

fixed stuffing

Container C-4 contains 3 times a 34 Mbit/s PDH Tributary (ETSI structure)

C-3 transport capacity: 84 X 9 x 64 kbit/s = 48.384 kBit/s84

C-3

J1B3C2G1F2H4Z3K3Z5

J1B3C2G1F2H4Z3K3Z5

J1B3C2G1F2H4Z3K3Z5

C334 Mbit/s

9 261

VC-3 #1VC-3 #2

VC-3 #3

VC-4 POH

VC-3 POH

Mapping 34 Mbit/s


RSOH

MSOH

AU pointer

VC-4

TUG-3

TUG-2

TU

-12

VC-12

Tu pointer

Mapping 2 Mbit/s


AU-4 Pointer

RSOH

MSOH

J1

B3

C2

G1

F2

H4

Z3

K3

Z5

1 2 3 4 5 6 7 8 9 10...........................................261

A B C A B C A A B C

S

T

U

F

F

I N

G

S

T

U

F

F

I N

G

. ......

1 86TUG-3(A)

. ......

1 86TUG-3(C)

. ......

1 86TUG-3(B)

Mapping and Multiplexing (1)


1 2 3 4 5 6 7 8 9 10...........................................86

NPI

E3 F3 G3S T

U

F

F I

N

G

S

T

U

F

F

I N

G

A1 B1 C1 D1 E1 F1 G1 A2

1 2 3 1 2 3 1 2 3 1 2 3

TU-12#1

TUG-2(A)

TU-12#3

.....

1 2 3 1 2 3 1 2 3 1 2 3

TU-12#1

TUG-2(B)

TU-12#3

.....

1 2 3 1 2 3 1 2 3 1 2 3

TU-12#1

TUG-2(G)

TU-12#3

.....

TUG-3NPI: Null Pointer Indication1001 XX11 1110 0000 XXXX XXXX

TU-12s occupy 36 bytes per frame

Mapping and Multiplexing (2)


V5R

32 bytes (32x8I)

RJ2

C1 C2 O O O O R R

32 bytes (32x8I)

32 bytes (32x8I)

32 bytes (32x8I)

RK4

R

N2R

C1 C2 O O O O R R

S2 I I I I I I I

14

0 B

yte

s

35 bytes in one VC-4

500 µs

V5: VC-12 Path OverheadR: fixed stuffing bitsJ2: Path TraceC1/2: Justification control bitO: Overhead bitN2: Network Operator byteK4: APSS2: Justification opportunity bitI: Info-bit

PayloadVC-4 Payload

V4

XXX XX00

PayloadVC-4 Payload

V1

XXX XX01

PayloadVC-4 Payload

V2

XXX XX10

PayloadVC-4 Payload

V3

XXX XX11

PayloadVC-4 Payload

V4

XXX XX00

VC-12 Structure:

H4: Indicates the number of VxV1,V2,V3: TU-12 Pointer

H4

H4

H4

H4

H4

VC-4 POH

Mapping 2 Mbit/s (asynchronous)


AU-4 Pointers

MSOH

RSOH

STM-4

VC-4-4c

J1

C2

G1

F2

H4

F3

K3

N1

C-4-4cF

ixe

d S

tuff

Fix

ed

Stu

ff

Fix

ed

Stu

ff

4 x 9 bytes 4 x 261 bytes

4 x 261 bytes

ATM CellThe first Pointer indicates J1All other Pointers are set to "Concatenation Indication"

B3

VC-4 Contiguous Concatenation


ATM switchSDH cross-connect for VC-4

ATM switch

150 Mbit/s

600 Mbit/s

In

Out

Out

In

Out

In

In

Out

VC-4-4c

STM-4c portSTM-4c port

STM-4 portSTM-4 port

150 Mbit/s

150 Mbit/s

150 Mbit/s

?VC4VC4

VC4VC4

4 x

Differentdelays for VC-4's?

622 Mbit/s622 Mbit/s

How to transport 600 Mbit/s ATM via 150 Mbit/s SDH?


Generation:All Pointers are set to the same valueAll VC-4 should be kept in the same STM-4All VC-4 are transported as individual VC-4's

AU-4 Pointers

MSOH

RSOH

STM-4

VC-4-4vc

J1

B3

C2

G1

F2

H4

F3

K3

N1

C-4-4vc

4 x 9 bytes 4 x 261 bytes

4 x 261 bytes

ATM Cell

J1

B3

C2

G1

F2

F3

K3

N1

H4

J1

B3

C2

G1

F2

H4

F3

K3

N1

J1

B3

C2

G1

F2

H4

F3

K3

N1

VC-4 Virtual Concatenation (Generation)


Termination:VC-4-4vc is reconstructed using the (different) pointer values for alignment

VC-4-4vc

J1B3C2G1F2H4F3K3N1

4 x 261 bytes

ATM Cell

J1B3C2G1F2H4F3K3N1

J1B3C2G1F2H4F3K3N1

J1B3C2G1F2H4F3K3N1

J1B3C2G1F2H4F3K3N1

C-4-4vc

J1B3C2G1F2

F3K3N1

H4

J1B3C2G1F2H4F3K3N1

J1B3C2G1F2H4F3K3N1

VC-4 #1VC-4 #2 VC-4 #3

VC-4 #4

VC-4 Virtual Concatenation (Termination)


E4: 139.264 kbit/s

DS3: 44.736 kbit/sE3 : 34.368 kbit/s

AUG C-4

TUG-3 TU-3 VC-3

C-3AU-3

x1

x3

x7

x7

x3

x1

STM-N

STS-3N

AU-4STS-3C

VC-4STS-3C SPE

STS-1

VC-3STS-1SPE

TUG-2 VTgroup

x3

xN

x1

x4

DS1: 1.544 kbit/sTU-11 VC-11

C-11VT-1.5 VT-SPE

E1: 2.048 kbit/sTU-12 VC-12

C-12 VT-2 VT-SPE

SDH

SONET

ITU-T G.707

BELLCORE GR.253ANSI T1.105

ATM: 149.760 kbit/s

ATM: 48,384 kbit/s

DS2: 6.312 kbit/sTU-2 VC-2

C-2 VT-6 VT-SPE

x1

STM-0

STS-1

SDH and SONET are International Standards


SDH Network Elements


SDH Network Elements

SDH Repeater

STM-n STM-n Applications:Line Signal Regenerationin Point-to-Point and Ring Networks

Terminal Multiplexer

STM-nPDH & STM-mTributariesm<n

Applications:Point-to-PointTransmission Systems(STM-1, STM-4, STM-16)


STM-1/4STM-1/4

Tributary Ports : n x 2 Mbit/s ( 34 Mbit/s)

ADM

......

WEST EAST

Add Drop Multiplexer


16x16x

4x 4x

VC11

34

2

SDH Multiplexer

VC 4 VC 3VC 12

2.4 Gbit/s

622 Mbit/s

2.4 Gbit/s

622 Mbit/s

140 Mbit/s

34 (45)Mbit/s

2 (1.5)Mbit/s

140 Mbit/s

34 (45)Mbit/s

2 (1.5)Mbit/s

155 Mbit/s155 Mbit/s

VC12

VC3

140

VC4

VC12

VC3

140

2

2

VC12

VC12

2

2

140

VC12

2

2

34

34

2

2

VC12

140 Mbit/s

34 Mbit/s 34 Mbit/s

140 Mbit/s

VC4

140

155VC4

155 Mbit/s

Synchronous Cross Connect


Optical Receive UnitSync

DEMUX4

4

4

4

OpticalTransmit UnitSync

MUX4

4

4

4

Management Communication Unit

Service Channel Unit

OverheadProcessing Unit

Data Channels

Service Channels

PC / TMN (Q)

16 x 140 Mbit/s

or

16 x STM-1

16 x 140 Mbit/s

or

16 x STM-1

STM-16

STM-16

SLX 1/16

Synchronous Line Equipment


2Mbit/s 34Mbit/s 140Mbit/s STM-1 STM-4

SDH

TM

DXC

ADMADM ATMSwitch

STM-4/-162Mbit/s

34Mbit/s

140Mbit/s

STM-1

LAN

2Mbit/s

ADM

STM-1

STM-1, STM-4

2Mbit/s

8Mbit/s

34Mbit/s

140Mbit/s

STM-1 / STS-3c Gateway to SONET

ADM : Add Drop MultiplexerDXC : Digital Cross ConnectTM : Terminal Multiplexer

Hybrid Networks Connect Old and New Technologies


Local Network

STM-4

STM-16

STM-1

STM-1Exchange

FlexMux

SubscriberAccess

Mux64/2M

LocalExchange

Trunk NetworkL 1

Trunk NetworkL 2

SDH Network Topology

SDH Network Topology

Trunk Network L 2


Synchronization Architecture in SDH


Synchronization Network

PRC

SSU SSU

Primary Reference Clock

Synchronization Supply Unit

SDH Equipment ClockSEC SDH Equip.

SEC SDH Equip.

SEC SDH Equip.

Caesium (Stratum 1) requ : 1 x 10-11

typ : 5 x 10 -12

long term: holdover 24h:

Rubidium (Stratum 2) requ : 1.6 x 10-8 , 1 x 10-10

typ : 4 x 10 -11 , 2 x 10-11


Limits:

Max. 10 x G.812 TNCMax. 60 x G.813 SEC, though no more than 20 between 2 TNCs

G.811 PRC

G.812 TNC

G.812 TNC

G.813 SEC

G.813 SEC

G.813 SEC

SSU SSU

Synchronization reference model


Synchronization of SDH Network Elements

SynchronousSDH Signal

155 Mbit/sData Signal

2 Mbit/sData Signal

2 048 kHz Central Clock

SDH Network Element

Osc.

InternalOscillator± 4.6 ppm


Phase error [ ns]

Observation interval [s]0.01 1 100 10000

10

100

1000

10000

100000

Hold-over mode


Hold-over measured values (TIE)


ITU-T ANSI / Bellcore ETSI

Definitions G.810 T1.101 / GR-253 ETS 300 462-1Network G.825 T1.105 / GR-253 ETS 300 462-3Primary Reference Clocks G.811 T1.101 ETS 300 462-6Synchron. Supply Clocks (ST2) G.812 T1.101 ETS 300 462-4Equipment Clocks (ST3) G.813 (G.81s) GR-253 ETS 300 462-5

Which Recommendations define Synchronization Networks


Monitoring, Maintenance and Control Functions in SDH


LOS Loss Of Signal LOS Loss Of Signal TSE Test Sequence Error (Bit Err.) TSE Test Sequence Error LSS Loss of Sequence Synchron. LSS Loss of Sequence Synchr.LTI Loss of incoming Timing Ref. LTI Loss of inc. TimingRef OOF Out Of Frame OOF Out Of FrameLOF Loss Of Frame LOF Loss Of FrameB1 Regenerator Section BIP Err. B1 Section BIP ErrorsB2 Multiplex Section BIP Err. B2 Line BIP ErrorsMS-AIS Multiplex Section AIS AIS-L Line AISMS-RDI Mux Sect. Remote Defect Ind. RDI-L Line remote Defect Ind.MS-REI Mux Sect. Remote Errro Ind. REI-L Line Remote Error Ind.AU-LOP Loss Of AU Pointer LOP-P SP Loss Of PointerAU-NDF New Data Flag AU Pointer NDF-P SP New Data FlagAU-AIS AU Alarm Ind. Signal AIS-P SP AISAU-PJE AU Pointer Just. EventB3 HO Path BIP Errors B3 SP BIP ErrorsHP-UNEQ HO Path Unequipped UNEQ-P SP UnequippedHP-RDI HO Path Remote Defect Ind. RDI-P SP Remote Deect. Ind.HP-REI HO Path Remote Error Ind. REI-P SP Remote ERrro Ind.

PDI-P SP Payload Defect Ind.HP-TIM HO Path Trace Ident. Mismatch TIM-P SP Trace Ident. MismatchHP-PLM HO Path Payload Label Mism. PLM-P SP Payload Label MismatchTU-LOP Loss Of TU Pointer LOP-V VP Loss Of PointerTU-NDF New Data Flag TU Pointer NDF-V VP New Data FlagTU-AIS TU AIS AIS-V VP AISTU-LOM Loss Of Multiframe LOM Loss Of MultiframeBIP-2/B3 LO Path BIP Errors BIP-2 VP BIP ErrorsLP-UNEQ LO Path Unequipped UNEQ-V VP UnequippedLP-RDI LO Path Remote Defect Ind. RDI-V VP Remote Defect Ind.LP-REI LO Path Remote Error Ind. REI-V VP Remote Error Ind.LP-RFI LO Path Remote Failure Ind. RFI-V VP Remote Failure Ind.

PDI-V VP Payload Defect Ind.LP-TIM LO Path Trace Ident. Mismatch TIM-V VP Trace Ident. MismatchLP-PLM LO Path Payload Label Mism. PLM-V VP Payload Label Mism.

Mu

x S

ect.

Mu

x S

ect.P

hys

./Reg

.Sec

t.P

hys

./Reg

.Sec

t.H

igh

er O

rder

Pat

hH

igh

er O

rder

Pat

hL

ow

er O

rder

Pat

hL

ow

er O

rder

Pat

h

Lin

e (L

)L

ine

(L)

ST

S P

ath

(S

P)

ST

S P

ath

(S

P)

VT

Pat

h (

VP

)V

T P

ath

(V

P)

Ph

ys./S

ecti

on

Ph

ys./S

ecti

on

LCD Loss of Cell Delineation I.610HCOR Correctable Header ErrorsHUNC Uncorrectable Header ErrorsVP-AIS Virtual Path AIS I.610VP-RDI Virtual Path Remote Defect Indication I.610VC-AIS Virtual Channel AIS I.610VC-RDI Virtual Channel Remot Defect Indication I.610Vx-AIS Virtual Channel AIS & Virtual, Path AIS simultan. (O.191)Vx-RDI Virtual Channel RDI & Virtual, Path RDI simultan. (O.191)LOC Loss Of Continuity I.610

AT

M P

ath

AT

M P

ath

EVENTS SDHEVENTS SDH EVENTS SONETEVENTS SONET


Frame Areas Covered by Parity Bytes

RSOH

MSOH

Payload

B1:- Supervision of the whole STM-1 frame- Covers the regenerator sections of a transmission system

B2:- Covers the multiplex sections (from network node to network node)

B3:- Covers the transmission paths from beginning to the end (tributary to tributary)

RSOH

MSOH

PayloadPayload

RSOH

MSOH

Parity bytes providing a means to supervise the transmission quality of a life STM-N signal !

PayloadAU-PTR


Parity Supervison Procedure

Tra

nsm

it S

ide

BIP-8 B1

frame nframe n+1


Parity Supervison Procedure

Tra

nsm

it S

ide

BIP-8 B1

frame nframe n+1

BIP-8 B1Comparisonwith the Tx side value

Rec

eive

Sid

e

frame n+1 frame n

recalculation at Rx side


How to Built a Parity Byte ?

Bit interleaved data field structure of the area covered Field width: BIP-24: 24 bits (B2) BIP-8: 8 bits (B1, B3) BIP-2: 2 bits (V5)

Column by column parity check for even numbers of "1"

BIP-24801

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 0 1 1 0 0 0 1 1 1 0 1 0 1 0 0 0 1 1 0 0 1 1 1 0 0 1 0 1 0 1 0 0 1 1 1 1 0 1 0 1 1

0 0 1 0 0 0 1 1 0 1 1 1 1 0 1 0 1 0 1 1 0 1 1 1

1 1 0 1 0 1 0 1 1 0 1 1 0 1 0 0 1 1 1 0 0 1 0 11 0 0 1 0 0 0 0 1 0 1 0 0 0 0 0 1 0 1 0 1 0 0 0

1

23

Byte 1 Byte 2 Byte 3

even numbers of "1"

Example: 24 bit interleaved parity check (BIP-24)


SDH MAINTENANCE INTERACTIONS

LOS/LOFRS-TIM

BIP Err.

"1"AIS

MS-AIS "1"

MS-BIP Err.

MS-REI

MS-RDI

AU-AIS

AU-LOP

AIS

"1"

HP-UNEQ

HP-TIM

HP-BIP Err.

HP-REI

HP-RDI

"1"AIS

TU-AIS

TU-LOP

LOM

HP-PLM

LP-UNEQ

LP-TIM

LP-BIP Err.

LP-REILP-RDI

LP-PLM

"1"

"1"

"1"

AIS

AIS

RegeneratorSection

MultiplexSection

Higher OrderPath

Lower OrderPath

(J0)

(B1)

(K2)

(B2)

(M1)

(K2)

(C2)

(J1)

(B3)

(G1)

(G1)

(H4)

(C2)

(V5)

(J2)

(V5)

(V5)

(V5)

(V5)


LOS Drop of incomming optical power level causes BER of 10-3 or worseOOF A1, A2 incorrect for more than 625 usLOF If OOF persists of 3msB1 Error Mismatch of the recovered and computed BIP-8MS-AIS K2 (bits 6,7,8) =111 for 3 or more framesB2 Error Mismatch of the recovered and computed BIP-24MS-RDI If MS-AIS or excessive errors are detected, K2(bits 6,7,8)=110MS-REI M1: Binary coded count of incorrect interleavedbit blocksAU-AIS All "1" in the entire AU including AU pointerAU-LOP 8 to 10 NDF enable or 8 to 10 invalid pointersHP-UNEQ C2="0" for 5 or more framesHP-TIM J1: Trace identifier mismatchHP-SLM C2: Signal label mismatchHP-LOM H4 values (2 to 10 times) unequal to multiframesequence

B3 Error Mismatch of the recovered and computed BIP-8HP-RDI G1 (bit 5)=1, if an invalid signal is received in VC-4/VC-3HP-REI G1 (bits 1,2,3,4) = binary coded B3 errors

Maintenance Signal Defenitions (1)


TU-AIS All "1" in the entire TU incl. TU pointerTU-LOP 8 to 10 NDF enable or 8 to 10 invalid pointersLP-UNEQ VC-3: C2 = all "0" for >=frames;

VC-12: V5 (bits 5,6,7) = 000 for >=5 framesLP-TIM VC-3: J1 mismatch; VC-12: J2 mismatchLP-SLM VC-3: C2 mismatch; VC-12: V5 (bits 5,6,7) mismatchBIP-2 Err Mismatch of the recovered and computed BIP-2 (V5)LP-RDI V5 (bit 8) = 1, if TU-2 path AIS or signal failure receivedLP-REI V5 (bit 3) = 1, if >=1 errors were detected by BIP-2LP-RFI V5 (bit 4) = 1, if a failure is declared

Abbreviations:

AU Administration unitHP High path

LOF Loss of frameLOM Loss of miltiframeLOP Loss of pointerLOS Loss of signal

LP Low pathOOF Out of frameREI Remote error indication (FEBE)RDI Remote defect indication (FERF)RFI Remote failure indicationSLM Signal label mismatch

TIM Trace identifierTU Tributary unitUNEQ UnequippedVC Virtual C container

Maintenance Signal Definitions (2)


ES Errored Second Second with> 1errored block

SES Severely Errored Second Second with > 30% errored blocks or > 1 defect

BBE Background Block Error Errored block, not occuring aspart of SES

ITU-T G.826ITU-T G.826ITU-T G.826ITU-T G.826

ES Errored Second Second with > 1 bit error

SES Severely Errored Second Second with BER > 1 x 10E-3

ITU-T G.821ITU-T G.821ITU-T G.821ITU-T G.821

UAS Unavailable Seconds:

Time10 sec 10 sec

< 10sec

Unavailable SecondsUnavailable Seconds

Unavailabilitydetected

Availabilitydetected

Performance Parameter


Jitter and Wander


0 1 2 3 4 5 6 7 8 9 . . .

Time Line

1 0 1 1 0 1 0 0 1 10 0Bit Sequence

1 UI

Ideal Signal (NRZ)

Actual Signal(with Jitter

and Wander)

Phase Variations (Jitter or Wander) in a Digital Transmission System

Jitter and Wander Definitions


• Interference signals

• Pattern dependent jitter

• Phase noise

• Delay variation

• Stuffing and wait time jitter

• Mapping jitter

• Pointer jitter

Sources of Jitter and Wander


Pattern

Clock

SignalInput

Ext. Reference Clock Input (Wander Measurement)

ClockInput

N

1

V

V

Pattern-ClockConverter

FrequencyDivider

Phase Detector

Phase Detector

~ 1 Hz

Filters

HP LP

Peak-to-PeakDetector

Low Pass Filter VCO

JitterandWander

Reference Clock Generator (PLL)

ResultEvaluation

Jitter and Wander Measurement Method


Amplitude / dB

Frequency / Hz10 Hz

STM-1: 500 Hz 65 kHz 1.3 MHzSTM-4: 1 kHz 250 kHz 5 MHzSTM-16: 5 kHz 1 MHz 20 MHz

HighFrequency

Jitter

Jitterincluding

lowerFrequency

Components

TotalJitter

Wander

Values according to ITU-T Rec. G.825 and G.813

Max. Jitter Amplitude: 1,5UI 0,15UI

Jitter Measurement Filters


JitterAmplitude

(PP)

Measurement Period

Jitter / UIpp

Time

Definition of Jitter Peak-to-Peak Amplitude


Network output jitter (G.825)

Network element output jitter (G.783, G.813)

Jitter transfer function (G.958)

Jitter and Wander tolerance (G.825, G.813)

Jitter and Wander Measurements


Wander Long-term timing variation (below 10 Hz)

TIE "Time Interval Error"

MTIE "Max. Time Interval Error"

TDEV "Time Deviation", timing variation as a function of integration time. Provides information about the spectral content.

TVAR "Time Variation", square of TDEV

ADEV "Allen Deviation"

MADEV "Modified Allen Deviation"

Definitions specified in ITU-T Rec. G.810

WANDER Definitions


MTIE

Observation Period

Start End

Wander / UI

Time

Slope representing

Frequency Offset

TIE at t End

TIE max

TIE min

Tim

e va

riat

ion

ag

ain

st r

efer

ence

TIE and MTIE Definition


Results (MTIE) compared to Standards


Network resilience


Linear Protection (G.783)

W

P

W

P

W

W

P

1 + 1 Protection scheme

1 : 1 Protection scheme

1 : N Protection scheme


Unidirectional and Bidirectional Rings

ADM

ADM

ADM

ADM

A

B

Traffic A -> B

Traffic B -> A

Unidirectional Ring

traffic between A-B uses the entire length of ring

Bidirectional Ring- use the shorter or longer path- increase number of paths- short path : traffic long path : protection

ADM

ADM

ADM

ADM

A

B

Traffic A -> B

B -> A

longer path


Unidirectional Path-Switched Ring

Tributary

Tributary

A

C

BF

D

E

Fiber 2 : unidirectional




Tributary

Tributary

A

C

BF

D

E




Unidirectional Line-Switched Ring

Tributary

Tributary

A

C

BF

D

E

Protection

Working

Working



Tributary

Tributary

A

C

BF

D

E

Protection

Working

Working


Two fiber Bidirectional Line-Switched Ring (BLSR)

Tributary

A

BF

C

D

E Tributary

Fiber 1

Fiber 2

workingprotection


Tributary

A

BF

C

D

E Tributary

Fiber 1

Fiber 2


workingprotection



Tributary

A

BF

C

D

E Tributary

Fiber 1

Fiber 2

workingprotection


Tributary

A

BF

C

D

E Tributary

Prot.Fiber 3 + 4

Working Fiber 1 + 2

Four fiber Bidirectional Line-Switched Ring (BLSR)



Tributary

A

BF

C

D

E Tributary

Prot.Fiber 3 + 4

Working Fiber 1 + 2


Four fiber Bidirectional Span-Switched Ring

Tributary

A

BF

C

D

E Tributary

Prot.Fiber 3 + 4

Working Fiber 1 + 2



Tributary

A

BF

C

D

E Tributary

Prot.Fiber 3 + 4

Working Fiber 1 + 2


TMN in SDH networks


Network Management

Basic tasks of network management:

Administrative functions:

Operation: Network supervising (anomalies, defects)Network linking (reserve links, additional links)

Maintenance: Identifing and elimination of impairments

Planning and commissioning: Network configuration

Operative functions: Supervision of network functionsRepairInstallationSelf test


TMN Overlay

CC CC

Central OS

Local OS

QQ

Q

Q

Q

Q ECC

ADM

AD

M

AD

M

ADM

Q ECC


PerformanceFaultsConfigurationAccountingSecurity

Management of :

DXC DXC

Central OS

Local OS

XX

Q3

Q3

Q3

Q ECC

ADM

AD

M

AD

M

ADM

QECC

Central OS

NEManager

NEManager

Q3

Data Communication Network : X.25, ISDN, LAN

Telecommunication Management Network (TMN) Overlay

STM-N

STM-N STM-N


TMN Reference Configuration

Operating System

OS

Mediation Device

MD

Network Element

NE

Data Communication Network

DCN

Network Element

NE

F

F

F

Q3

Q3

Q2 or Q1

Qx

Q3

Workstation

Workstation

Workstation

MD: Conversion between different interfaces(Information Conversion Function ICF:manufacturer-specific information model ->operator specific information model)

Local Communication Network

LCN


Interoperability in TMN

QMonitor provides easy adaptation to the interface

(autoconfiguration)

decoding of protocols and management information

automatic detection of errors in management information

SDH/SONET Qecc access with transmission analyzers (e.g. ANT-20)

QMonitor based on DominoWANDominoLAN DA-30

TMNOperations

System

TMNOperations

System

Qecc Qecc

Qecc

Q3

Q3

XX Interoperability problems because of– multi vendor networks

– heterogenous technology

– different standards for protocols and management information


SDH Benefits

Reduced equipment costsmulti vendor compatibility

Lower maintenance costsbuilt-in defect and anomaly monitoring

Future proof equipmentSDH is the physical layer for BISDN

Efficient drop / insert facilitiesADM (add&drop multiplexers), DXC (digital cross connectors)

TMN capabilitiesBuilt-in DCN (data comm. network), DCC/ECC

More flexibility in provision of servicesadding transmission capacity by routing on demand


Pirelli : WaveMux 320032 x OC-48 channels80Gbit/s over 1200km

40 x OC-48 channels100Gbit/s over 600km

Ciena :

There may not be a near term need, but this is the direction that networking will take next for 3 or 4 years.

Ryan, Hunkin, Kent Consulting '96

Future Trends - WDM Systems

Current Systems : 4, 8, 16 x OC-48 (MCI, Sprint)


Future Trends - Optical ComponentsFuture Trends - Optical Components

ADM

Optical D&I

Local Traffic2Mbit/s, DS-3, STM-1

WDM WDM

STM-N,OC-N

STM-N,OC-N

Extract selectively Minimize need for demultiplexing

entire bandwidth


STM-16c VC2-5c PoS

STM-64

DWDM

Larger Capacity

Optical Networks

Additional Mappings

FutureTrendsin Synchronous Technology

TMN Q3 Worldwide


Let‘s summarize !

•Please name the PDH bitrates !

•Please explain „stuffing“ !

•When will „stuffing“ be applied ?

•What is the reaction of a Network element after an „LOS“ alarm ?

•What is the meaning of an „LOF“ alarm ?

•Is it possible to drop an 2Mbit/s signal out of an 140Mbit/s line ?

•Why not ?

•Please name the SDH bitrates !

•Explain the way an PDH signal is integrated in an STM-1 !


Let‘s summarize !

•Please name the different sections of an SDH connection !

•What is a parity byte ?

•Please explain the way to build a parity byte !

•Which parity bytes do you know ?

•Which overhead bytes are used for data communication ?

•What is a „pointer“ ?

•What is a „pointer“ used for ?


Let‘s summarize !

•Please name the SDH network elements !

•What are they used for ?

•Please explain how a synchronization network looks like !

•What is a holdover mode ?

•Which byte is used to transport an HP-UNEQ ?

•Please explain „Jitter“ and „Wander“ !

•How can jitter be defined ?

•Please explain the terms TIE and MTIE ?

•Please explain the term TDEV ?

•Explain the possibilities to synchronize a NE !


Let‘s summarize !

•Please name the main Jitter and Wander measurements !

•Explain these measurements !

•Please explain the methods of linear protection !

•What kind of ring structures do you know ?

•Please explain „DWDM“ !

•What are the the advantages of a TMN controlled network ?

•How is the TMN interface called ?

sdh_all

Documents

kbits x

kbits frame

kbits data signals1

kbits 20ppm1

sa sa sa

frame alignment signal

mbits frame structures

voice data signals time