sdh networks.ppt

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Communications Test Solutions 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

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.

Copyright by Stephan Schultz, Wandel & Goltermann Germany

Box 1262, D-72795 Eningen u.A.e-mail: [email protected]

http://www.wg.com

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 XXX0 0 1 0 X XXX

1 0 0 0 X XXX

1 0 0 1 X XXX

1 0 1 0 X XXX1 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 codes

-V

In accordance withCCITT’s A-law

1/2V1/4V

1/8V

1/16V

1/32V

1/64

V

Quantization

Level

3248

648096112

Non-Linear Quantization and Encoding




8

bits persamplex = 64kbit /s

8000

samplesper sec

PCM Signal Data Rate




Time Division Multiplexing (TDM)




2048 kbit/s

64 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.

32064 kbit/s

x 3

97728 kbit/s

397200 kbit/s

x 4

x 4

34368 kbit/s

139264 kbit/s

x 4

564992 kbit/s

x 4

8448 kbit/s

44736 kbit/s

274176 kbit/s

x 6

1544 kbit/s

6312 kbit/s

x 4

PDH Systems World-wide




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

encoded voice / data signals encoded voice / data signals

signalling

information

time

slots0 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 use

Sa4: 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


signalling

information

time

slots

Si 1 A Sa Sa Sa Sa Sa4 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








Y: Remote MF alarm (1=Alarm)

E: CRC error indication (0=Error)

Sa4 to Sa8: Spare bits or used for message baseddata links (point-to-point applications)


NFAS: Not frame alignment signal

signalling

subscr. n

signalling

subscr. n+15


Si 0 0 1 1 0 1 1


signallinginformation

time

slots


FAS

(frames 0,2,4...)

NFAS

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

0 0 0 0 x Y x x

a b c d a b c d

MFAS NMFAS

frame 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





Sa4 to Sa8: Spare bits or used for message based




signalling

subscr. n

signalling

subscr. n+15


Si 0 0 1 1 0 1 1


signalling

information

time

slots


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

NFAS

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

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





2.048 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





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




signalling

subscr. n

signalling

subscr. n+15

Si 0 0 1 1 0 1 1


FAS

(frames 0,2,4...)

NFAS

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

0 0 0 0 x Y x x

a b c d a b c dMFAS NMFAS

frame 0

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

Time slot 0 of CRC multiframe:

s u b m u l t i f r a m e 1

s u b m u l t i f r

a m e 2



signalling

information

time

slots0 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





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 Bit

N: National Spare Bit

1a: Stuffing Control Bit

S: 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 Bit


1a: Stuffing Control Bit

S: 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 s41a 2a 3a 4a 1b 2b 3b 4b





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

A: Alarm Bit


1a,b,c,d: Stuffing Control Bit

S: 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





AISPDH

Equipment

AISPDH

Equipment

LOS

LOF

AIS

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 TerminatingUnit

Line TerminatingUnit

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 Why SDH




2Mbit/s

34Mbit/s140Mbit/s

STM-1

STM-4

STM-1 / STS-3c Gateway to SONET

TM

DXC

ADMADMATM

Switch

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

ADM : Add Drop Multiplexer

DXC : Digital Cross ConnectTM : Terminal Multiplexer

DSC: Digital Switching Center

LAN: Local Area Network

DSC

Synchronous Network Structure




VC-2

VC-1

VC-2

VC-1

VC-4VC-3VC-12

VC-4

VC-3

VC-2

VC-1

VC-4 VC-3 VC-12

VC-4

VC-3

Reg S M X

S M X

Multiplex

Section

Regenerator

Sections

Higher Order PathLower Order Path

STM-n

RSOH

STM-n

RSOH

STM-n MSOH

VC-4/3 POH

VC-1/2/3 POH

Path Denominations




M U X /

D E M U X

M U X /

D E M U XPDH PDH

SDH SDH SDH

Reg.

CC

NNI NNI NNI

ITU-T Rec.: G.707 Synchronous Multiplex Structure

G.703 Electrical characteristic

G.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 Interfacesin SDH




RSOH: Regenerator section overhead

MSOH: Multiplex section overhead

Payload: Area for information transport

Transport capacity of one Byte: 64 kbit/s

Frame capacity: 270 x 9 x 8 x 8000 = 155.520 Mbit/s

Frame repetition time: 125 µs

1

3

5

9

4

270

270 Columns (Bytes)

1 9transmit

row by row

RSOH

MSOH

AU Pointer Payload(transport capacity)

STM-1 Frame Structure




C-4





VC-4

C-4

V C - 4 P O H





AU Pointer

AU-4

VC-4

C-4

V C - 4 P O H





1

3

5

9

4

270

270 Columns (Bytes)

1 9

RSOH AU-4

MSOH

AU PointerVC-4

V C - 4 P O H

C-4





12341234123412 . . . .

11111

22222

33333

44444

STM-1 #1

STM-1 #2

STM-1 #3

STM-1 #4

STM-4

The STM-4/16/64 bit rate is obtained as integer multiples of the STM-1 tributary bit rate.

Clock offset at the tributary side is taken into consideration by pointer adaptation on the

STM-n output signal.

B1B2

B1B2

SOH termination New SOH

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

S1 M1 E2 X 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




M U X /

D E M U X

M U X /

D E M U X

back-up line

PDH PDH

SDH SDH SDH

Multiplex Section Multiplex SectionRegenerator 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

B1

Reg. Section

Synchronous Network




J1

B3

C2

G1

F2

H4

F3

K3

N1

V5

J2

N2

K4

AU - PTR

VC-3/4 POH

VC-11/12/ 2 POH

STM-1 SOH

Media dependent bytesX Reserved for national use

SOH: Section overhead

POH: Path overhead

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

RSOH

MSOHPayload

P

O

H

Pointer

A1 A1 A1 A2 A2 A2 J0 X X

D1 D2 D3

B2 B2 B2 K1 K2

D4 D5 D6D7 D8 D9

D10 D11 D12

S1 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 Identficationof 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

F ti f P th O h d




Parity checkB3, V5/ BIP-2 calculated by path terminating point

Alarm and performance information(V5, G1)

Structure of the VCSignal label C2

Multiframe indication for TUs (H4)

User communications channelbetween path elements (F2, F3)

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

J1

B3C2

G1

F2

H4

F3

K4

N1

V5

J2

N2

K4

VC-3/4 POH

VC-11/12/2

POH

Functions of Path Overhead

Functions and Characteristics of the





Individual Elements of NNI

• 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





• 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


Individual Elements of the NNI

Overhead Byte Functionality




A1, A2 Frame synchronisationB1, B2 Parity bytes for transmission error monitoringJ0 Regenerator section traceD1... 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 trace

B3 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 label

J2 Lower order path traceN2 Network operator byte (Tandem Connection Monit.)K4 Automatic protection switching (APS)

SOH

VC-3/4

POH

VC-1/2

POH

Overhead Byte Functionality

Th f i t ti PDH i l i t STM 1




Container

Virtual Container

Administrative Unit

Synchronous 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

P i t




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

V C - 4

P O H

VC-12POH

VC-12

VC-4

STM-1

Pointers

Use of the AU 4 Pointer Area Coding




H1 Y Y H2 1 1 H3 H3 H3

Opportunity for

negative stuffing

(more capacity)

Pointer

inc/dec

IDIDIDID

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 XX 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 for

positive 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

Not Synchronous SDH Networks




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 withinverted D bits

New pointer

Actual pointer

Not Synchronous SDH Networks

Mapping 140 Mbit/s




AU Pointer

RSOH

MSOH

9 261

J1B3

C2

G1

F2

H4

Z3

K3

Z5

20 x 13 bytes per row

C-4

140 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

Mapping of a 140 Mbit/s Tributary into VC 4




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

I = Information bit

S = Justification opportunity bit

R = Fixed stuffing bit

C = 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

Mapping 34 Mbit/s




AU Pointer

RSOH

MSOH

J1

B3

C2

G1

F2

H4

Z3

K3

Z5

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

J1

B3C2

G1

F2

H4

Z3

K3

Z5

J1B3

C2

G1

F2

H4

Z3

K3

Z5

J1

B3

C2

G1

F2

H4

Z3

K3

Z5

C3

34 Mbit/s

9 261

VC-3 #1VC-3 #2

VC-3 #3

VC-4 POH

VC-3 POH

Mapping 34 Mbit/s

Mappings 2 Mbit/s




RSOH

MSOH

AU pointer

VC-4

TUG-3

TUG-2

T U - 1

2

VC-12

Tu pointer

Mappings 2 Mbit/s

Mapping and Multiplexing (1)




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)






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

N

PI

E3 F3 G3 S

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 Indication

1001 XX11 1110 0000 XXXX XXXX

TU-12s occupy

36 bytes per

frame


Mapping 2 Mbit/s (asynchronous)




V5R

32 bytes (32x8I)

RJ2

C1 C2 O O O O R R

32 bytes (32x8I)

32 bytes (32x8I)

32 bytes (32x8I)

RK4

R

N2RC1 C2 O O O O R R

S2 I I I I I I I

1 4 0 B y t e

s

35 bytes

in one

VC-4

500 µs

V5: VC-12 Path Overhead

R: fixed stuffing bits

J2: Path Trace

C1/2: Justification control bit

O: Overhead bit

N2: Network Operator byte

K4: APS

S2: Justification opportunity bit

I: Info-bit

Payload

VC-4 Payload

V4

XXX XX00

Payload

VC-4 Payload

V1

XXX XX01

PayloadVC-4 Payload

V2

XXX XX10

Payload

VC-4 Payload

V3

XXX XX11

PayloadVC-4 Payload

V4

XXX XX00

VC-12 Structure:

H4: Indicates the number of Vx

V1,V2,V3: TU-12 Pointer

H4

H4

H4

H4

H4

VC-4 POH

Mapping 2 Mbit/s (asynchronous)

VC-4 Contiguous Concatenation




AU-4 Pointers

MSOH

RSOH

STM-4

VC-4-4c

J1

C2

G1

F2

H4

F3

K3

N1

C-4-4c

F i x e

d S t u f f

F i x e

d S t u f f

F i x e d

S t u f f

4 x 9 bytes 4 x 261 bytes

4 x 261 bytes

ATM Cell

The first Pointer indicates J1 All other Pointers are set to "Concatenation Indication"

B3

VC 4 Contiguous Concatenation

How to transport 600 Mbit/s ATM via

150 Mbit/ SDH ?




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 port

STM-4 port

150 Mbit/s

150 Mbit/s

150 Mbit/s ?VC4

VC4VC4

VC4

4 x

Different

delays for VC-4's?

622 Mbit/s622 Mbit/s

150 Mbit/s SDH ?

VC-4 virtual Concatenation (Generation)




Generation:

All Pointers are set to the same value

All VC-4 should be kept in the same STM-4 All VC-4 are transported as individual VC-4's

AU-4 Pointers

MSOH

RSOH

STM-4

VC-4-4vc

J1

B3

C2

G1

F2H4

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

F2H4

F3

K3

N1

J1

B3

C2

G1

F2H4

F3

K3

N1

( )



SDH and SONET are International Standards




E4: 139.264 kbit/s

DS3: 44.736 kbit/s

E3 : 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-4

STS-3C

VC-4

STS-3CSPE

STS-1

VC-3

STS-1

SPE

TUG-2VT

group

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-12VT-2 VT-SPE

SDH

SONET

ITU-T G.707

BELLCORE GR.253

ANSI T1.105

ATM: 149.760 kbit/s

ATM: 48,384 kbit/s

DS2: 6.312 kbit/sTU-2 VC-2 C-2VT-6 VT-SPE

x1

STM-0

STS-1

SDH Network Elements




SDH Network Elements




SDH Repeater

STM-n STM-n Applications:

Line Signal Regeneration

in Point-to-Point and RingNetworks

Terminal Multiplexer

STM-nPDH &

STM-m

Tributaries

m<n

Applications:

Point-to-Point

Transmission Systems

(STM-1, STM-4, STM-16)

Add Drop Multiplexer




STM-1/4STM-1/4

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

ADM

......

WEST EAST

Synchronous Cross Connect




16x16x

4x 4x

VC11

34

2

SDH

Multiplexer

VC 4

VC 3

VC 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 Line Equipment




OpticalReceive

UnitSync

DEMUX

4

4

4

4

OpticalTransmit

UnitSyncMUX

4

4

4

4

ManagementCommunication Unit

Service Channel Unit

OverheadProcessing Unit

DataChannels

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

Hybrid Networks Connect Old and

New Technologies




2Mbit/s

34Mbit/s

140Mbit/sSTM-1

STM-4SDH

STM-1 / STS-3c Gateway to SONET

TM

DXC

ADMADMATM

Switch

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

ADM : Add Drop Multiplexer

DXC : Digital Cross ConnectTM : Terminal Multiplexer

New Technologies

STM-4

Trunk NetworkTrunk

Network L 2




Local Network

STM-16

STM-1

Exchange

FlexMux

SubscriberAccess

Mux64/2M

Local

Exchange

Trunk Network

L 1

Trunk Network

L 2

SDHNetwork Topology

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

Synchronization reference model




Limits:

Max. 10 x G.812 TNC

Max. 60 x G.813 SEC,

though no more than20 between 2 TNCs

G.811

PRC

G.812

TNC

G.812

TNC

G.813

SEC

G.813

SEC

G.813

SEC

SSU SSU

Synchronization of SDH Network Elements




Synchronous

SDH Signal

155 Mbit/s

Data Signal

2 Mbit/s

Data Signal

2 048 kHz

Central Clock

SDH Network Element

Osc.

Internal

Oscillator

± 4.6 ppm

Hold-over mode




Phase error [ ns]

Observation interval [s]0.01 1 100 10000

10

100

1000

10000

100000

Hold-over measured values (TIE)




Which Recommendations defineSynchronization Networks




ITU-T ANSI / Bellcore ETSI

Definitions G.810 T1.101 / GR-253 ETS 300 462-1

Network G.825 T1.105 / GR-253 ETS 300 462-3

Primary Reference Clocks G.811 T1.101 ETS 300 462-6Synchron. Supply Clocks (ST2) G.812 T1.101 ETS 300 462-4

Equipment Clocks (ST3) G.813 (G.81s) GR-253 ETS 300 462-5

Monitoring, Maintenance and Control Functionsin SDH




LOS Loss Of Signal LOS Loss Of SignalTSE Test Sequence Error (Bit Err.) TSE Test Sequence ErrorLSS Loss of Sequence Synchron. LSS Loss of Sequence Synchr.LTI Loss of incoming Timing Ref. LTI Loss of inc. TimingRefOOF Out Of Frame OOF Out Of FrameLOF Loss Of Frame LOF Loss Of FrameB1 R S i BIP E B1 S i BIP E

P h y s . / R e g .

S e c t .

P h y s . / S e c t i o n

EVENTS SDH EVENTS SONET




B1 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 Pointer

AU-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 Multiframe

BIP-2/B3 LO Path BIP Errors 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.

M u x S e c t .

H i g h e r O r d e r P a

t h

L o w e r O

r d e r P a t h

L i n e ( L )

S T S P a t h ( S P

)

V T P a t h

( V P )

P

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.610

VC-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

A T

M P a t h

Parity bytes providing a means to supervise the transmission

Frame Areas Covered by Parity Bytes




RSOH

MSOH

Payload

B1:

- Supervision of the

whole STM-1 frame

- Covers the regenerator

sections of a trans-

mission 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 !

Payload AU-PTR

Parity Supervison Procedure




T r a n s m i t S i d e

BIP-8 B1

frame nframe n+1

Parity Supervison Procedure




Comparisonwith the Tx side value

T r a n s m i t S i d e

BIP-8 B1

frame nframe n+1

BIP-8 B1

R e c e i v e S i d e

frame n+1 frame n

recalculation at Rx side

Bit interlea ed data field str ct re of the area co ered

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-24

801

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

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

123

Byte 1 Byte 2 Byte 3

even numbers of "1"

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

Regenerator Multiplex Higher Order Lower Order

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-REIHP-RDI

"1" AIS

TU-AIS

TU-LOP

LOM

HP-PLM

LP-UNEQ

LP-TIM

LP-BIP Err.

LP-REI

LP-RDILP-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)

Maintenance Signal Definitions (1)




LOS Drop of incomming optical power level causes BER of 10-3 or worse

OOF A1, A2 incorrect for more than 625 us

LOF If OOF persists of 3msB1 Error Mismatch of the recovered and computed BIP-8

MS-AIS K2 (bits 6,7,8) =111 for 3 or more frames

B2 Error Mismatch of the recovered and computed BIP-24

MS-RDI If MS-AIS or excessive errors are detected, K2(bits 6,7,8)=110

MS-REI M1: Binary coded count of incorrect interleavedbit blocks

AU-AIS All "1" in the entire AU including AU pointer

AU-LOP 8 to 10 NDF enable or 8 to 10 invalid pointers

HP-UNEQ C2="0" for 5 or more framesHP-TIM J1: Trace identifier mismatch

HP-SLM C2: Signal label mismatch

HP-LOM H4 values (2 to 10 times) unequal to multiframesequence

B3 Error Mismatch of the recovered and computed BIP-8

HP-RDI G1 (bit 5)=1, if an invalid signal is received in VC-4/VC-3

HP-REI G1 (bits 1,2,3,4) = binary coded B3 errors

Maintenance Signal Definitions (2)




TU-AIS All "1" in the entire TU incl. TU pointer

TU-LOP 8 to 10 NDF enable or 8 to 10 invalid pointers

LP-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 mismatch

LP-SLM VC-3: C2 mismatch; VC-12: V5 (bits 5,6,7) mismatch

BIP-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 received

LP-REI V5 (bit 3) = 1, if >=1 errors were detected by BIP-2

LP-RFI V5 (bit 4) = 1, if a failure is declared

Abbreviations:

AU Administration unit

HP High path

LOF Loss of frame

LOM Loss of miltiframe

LOP Loss of pointer

LOS Loss of signal

LP Low path

OOF Out of frame

REI Remote error indication (FEBE)

RDI Remote defect indication (FERF)

RFI Remote failure indication

SLM Signal label mismatch

TIM Trace identifier

TU Tributary unit

UNEQ Unequipped

VC Virtual

C container

Perfomance Parameter

ITU T G 821




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.826

ES Errored Second Second with > 1 bit error

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

UAS Unavailable Seconds:

Time10 sec 10 sec

< 10secUnavailable Seconds

Unavailabilitydetected Availabilitydetected

ITU-T G.821

Jitter and Wander




Jitter and Wander Definitions




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

Sources of Jitter and Wander




• Interference signals

• Pattern dependent jitter

• Phase noise

• Delay variation

• Stuffing and wait time jitter

• Mapping jitter

• Pointer jitter

Jitter and Wander Measurement Method




Pattern

Clock

SignalInput

Ext. Reference Clock Input(Wander Measurement)

ClockInput

N

1V

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

Amplitude / dBValues acco rdin g to ITU-T Rec. G.825 and G.813

Jitter Measurement Filters




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

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

Definition of Jitter Peak-to-Peak Amplitude




JitterAmplitude

(PP)

Measurement Period

Jitter / UIpp

Time

Jitter and Wander Measurements




• 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)

Wander Long-term timing variation (below 10 Hz)

WANDER Definitions




a de o g e g a a o (be o 0 )

TIE "Time Interval Error"

MTIE "Max. Time Interval Error"

TDEV "Time Deviation", timing variation as a function ofintegration time. Provides information about thespectral content.

TVAR "Time Variation", square of TDEV

ADEV "Allen Deviation"

MADEV "Modified Allen Deviation"

Definitions specified in ITU-T Rec. G.810

TIE and MTIE Definitions




MTIE

Observation Period

Start End

Wander / UI

Time

TIE at t End

TIE max

TIE min T i m e v a r i a

t i o n a g a i n s t r e f e r e n c e

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

Linear Protection (G.783)




W

P

W

P

W

W

P

1 + 1 Protection scheme

1 : 1 Protection scheme

1 : N Protection scheme

ADMTraffic A -> B ADM

Traffic A -> B

Unidirectional and Bidirectional Rings




ADM

ADM

ADM

ADM

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

A

B

B -> A

longerpath

Fiber 1 : unidirectional

Unidirectional Path-Switched Ring




Tributary

Tributary

A

C

BF

D

E






Working

Unidirectional Line-Switched Ring




Tributary

Tributary

A

C

BF

D

E

Protection

Working

Working

Unidirectional Line-Switched Ring




Tributary

Tributary

A

C

BF

D

E

Protection

Working

Fiber 1

Two fiber Bidirectional Line-Switched Ring (BLSR)




Tributary

A

BF

C

D

E Tributary

Fiber 2

working

protection

Fiber 1

Two fiber Bidirectional Line Switched Ring

(BLSR)




Tributary

A

BF

C

D

E Tributary

Fiber 2

working

protection

Fiber 1

Two fiber Bidirectional Line-Switched Ring

(BLSR)




Tributary

A

BF

C

D

E Tributary

Fiber 2

working

protection

AProt 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

AProt 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



AProt.Fiber 3 + 4

Working Fiber 1 + 2

Four fiber Bidirectional Span-Switched Ring




Tributary

A

BF

C

D

E Tributary

Prot.Fiber 3 4

AProt.Fiber 3 + 4

Working Fiber 1 + 2

Four fiber Bidirectional Span-Switched Ring




Tributary

A

BF

C

D

E Tributary

ot be 3

TMN in SDH networks



TMN Overlay

Central QQ




CC CC

Central

OS

Local

OS

QQ

Q

Q

Q

Q ECC

ADM

ADM A

D M

ADM

Q ECC

Management of :

Telecommunication Management Network(TMN) Overlay




PerformanceFaults

Configuration

Accounting

Security

DXC DXC

Central

OS

Local

OS

XX

Q3

Q3

Q3Q ECC

ADM

ADM A

D M

ADM

QECC

Central

OS

NE

Manager

NE

Manager

Q3

Data Communication Network : X.25, ISDN, LAN

STM-N

STM-N STM-N

TMN Reference Configuration

Operating

System

OS F




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



Reduced equipment costsmulti vendor compatibility

SDH Benefits




Lower maintenance costsbuilt-in defect and anomaly monitoring

Future proof equipmentSDH is the physical layer for BISDN

Efficient drop / insert facilities ADM (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

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

Future Trends - WDM Systems




Pirelli : WaveMux 3200

32 x OC-48 channels

80Gbit/s over 1200km

40 x OC-48 channels

100Gbit/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

, , ( , p )

WDM WDM

Future Trends - Optical Components




ADM

Optical D&I

Local Traffic

2Mbit/s, DS-3, STM-1

l1, l2, l3, l4

l2

l1, l2, l3, l4

l2

WDM WDM

STM-N,

OC-N

STM-N,

OC-N

Extract selectively

Minimize need for demultiplexing

entire bandwidth

STM-64




STM-16c

VC2-5c

PoS

DWDMFuture

Trends

in

SynchronousTechnology

TMN

•Please name the PDH bitrates !

Pl l i t ffi “ !

Let‘s summarize !




•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 !

•Please name the different sections of an SDH connection !

Let‘s summarize !




•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 ?

•Please name the SDH network elements !

Let‘s summarize !




•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 !

•Please name the main Jitter and Wander measurements !

Let‘s summarize !




•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 networks.ppt

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