BBCOM_SDH

8/8/2019 BBCOM_SDH

1/66

8/8/2019 BBCOM_SDH

2/66

Lars Dittmann, [email protected]

Synchronization problem

Multiplexing of N channels must adopt to

highest rate (N x highest rate - rather thansum)

Clock distribution depending on local

oscillators and network structure

Must incorporate case of failure

8/8/2019 BBCOM_SDH

3/66


Multiplexing

f1f2f3

f4

f5f6

f8

f7

f9f10

f11

f12f13f14f15

f16

4 x maxf

4 x maxf

4 x maxf

4 x maxf

4 x maxf

8/8/2019 BBCOM_SDH

4/66


Net synchronization

1 2 3n 1 2 3 n 1 2 3 n1 2 3 n

core network

node

access

node

????

8/8/2019 BBCOM_SDH

5/66


Framing in circuit switching

11 121097 865 19 20181715 161413 27 28262523 2422213 42131 03029 3 42131 03029

125 sec

Basic PDHframingstructure

Destination determined by frame possition

8/8/2019 BBCOM_SDH

6/66


PDH Multiplex hierarchy

Multiplex hierarchy, European standard

System Data speed, Mbit/s Number of channels

DS-1E 2,048 30

DS-2E 8,448 120

DS-3E 34,368 480

DS-4E 139,264 1920DS-5E 564.992 7680

(4)

DS-1E

(4)

DS-2E

(4)

DS-3E

M34E

(4)

DS-4E

M45E

DS-5EM23E

M12E

8/8/2019 BBCOM_SDH

7/66


Plesiochronous add and drop

8/8/2019 BBCOM_SDH

8/66

8/8/2019 BBCOM_SDH

9/66


The history of SONET/SDH

SONET proposed standard by BELLCORE at thetime when ITU/CCITT was working on global

standard

A (simplified) version adopted by ITUG.707/708/709 now one standard G.707

Still minor differences in SDH and SONET - NOTjust plug and play.

Now a general accepted standard - even non-SDHnetworks are using SDH-framing

Simplified (not all function fields supported)

versions in datacom e.g. 10GE, DPT/SRP etc.

8/8/2019 BBCOM_SDH

10/66


SDH in brief

SDH is synchronous, i.e. all elements use one clock as reference.

SDH provide simpel multiplexing and allow direct access

to lower level signals.

SDH defines optical standards => midspan meet possible

SDH can be introduced into existing systems

SDH is prepared for carrying many signal types such as:

ETSI-PDH, ANSI-PDH and ATM.

SDH include management channels embedded in the signal.

SDH enable the possibility of a centralized network control.

SDH advantages

8/8/2019 BBCOM_SDH

11/66


SDH network structure

S D H le v e l D a t a s p e e d

S T M -1 1 5 5 5 2 0 k b /s

S T M -4 6 2 2 0 8 0 k b /s

S T M -1 6 2 4 8 8 3 2 0 k b /s

S T M -6 4 9 9 5 3 2 8 0 k b /s

Regionalnetwork

Regional

network

Regional

network

Localnetwork

Localnetwork

Localnetwork

Localnetwork

Localnetwork

Localnetwork

STM-1

STM-1

STM-1

STM-1STM-1

STM-1

STM-4/STM-16

STM-16/STM-64

core network STM-4/STM-16

STM-4/STM-16

8/8/2019 BBCOM_SDH

12/66


SONET vs. SDH

SONET = ANSI (American standard)

SDH = International Standard SDH basic unit = STM-1 = 155 Mbit/s

SONET basic unit STS-1 = OC-1 = 51 Mbit/s

8/8/2019 BBCOM_SDH

13/66


SDH og PDH

Customer

SDH-island

PDHnetwork

PDHnetwork

High speedSDH-line

Customer

SDH-island

8/8/2019 BBCOM_SDH

14/66


Network element 1

SDXCsynchronous digital cross connect

SDXC STM - n

(m

8/8/2019 BBCOM_SDH

15/66


Network element 2

ADMadd / drop multiplexer

ADM STM - n

(m

8/8/2019 BBCOM_SDH

16/66


Network element 3

Muxmultiplexer

Multiplexer STM - n

STM - m

(m

8/8/2019 BBCOM_SDH

17/66


Network element 4

Regregenerator

Regenerator STM - nSTM - n

Regenerate the signalSignal supervision

8/8/2019 BBCOM_SDH

18/66


Layered structure

T1816750-92/d11

Circuit layer networks

VC-11 VC-12 VC-2 VC-3

VC-3 VC-4

Multiplex section layer

Regenerator section layer

Physical media layer

Circuit

layer

Lower

order

pathlayer

Path

layer

SDH

transport

layers

Higher

orderpath

layer

Section

layerTransmission

media

layer

8/8/2019 BBCOM_SDH

19/66


SDH structure

Path layer:low-order pathhigh-order path

Transmission medium layer:Multiplexer sectionRegenerator sectionPhysical medium (e.g. fiber)

8/8/2019 BBCOM_SDH

20/66


Overhead

Overhead is generated at:

Regenerator section

Multiplekser section End-to-end high-order path

End-to-end low-order path

8/8/2019 BBCOM_SDH

21/66


SDH

frame structure

8/8/2019 BBCOM_SDH

22/66


Multiplexing structure

European multiplexing of low-order signals into a SDH signal

Multiplexed TUs

Pointer added

Overhead added

Input container

Overhead added

Pointer added

Multiplexed AUs

Overhead added

F t i 1 t STM N

8/8/2019 BBCOM_SDH

23/66


From container 1 to STM-N

T1819910-93/D03

VC-1

TU-1

TUG-2

TUG-3

VC-4

AU-4

AUG

STM-N

Container-1

VC-1 POH Container-1

VC-1

VC-1VC-1

TU-1 PTR

TU-1 PTRTU-1 PTR

TUG-2 TUG-2

VC-4 POH TUG-3 TUG-3

AU-4 PTR VC-4

VC-4AU-4 PTR

SOH AUG AUG

Logical association

Physical association

PointerPTR

BIP 8 l l i

8/8/2019 BBCOM_SDH

24/66


BIP-8 calculationCalculation of a BIP-8

Bit-stream : 1011 0010 0100 1101 1011 0011 1110 0101

BIP-8 => In a group of bits:

Number of 1 even => parity bit 0Number of 1 odd => parity bit 1

T i i

8/8/2019 BBCOM_SDH

25/66


Transmission system

TX

Site A

RX

RX

Site C

TX

RX TX

Site B

TX RX

If site B have problems with a signal from site A

Upstream to A

Remote Defect Indication (RDI)former (Far End Receive Failure (FERF))

Remote Error Indication (REI)former (Far End Block Error (FEBE))

Downstream to C Alarm Indication Signal (AIS) of appropriate type

O h d

8/8/2019 BBCOM_SDH

26/66


Overhead


Multiplexed TUs

Pointer added

Overhead added

Input container

Overhead added

Pointer added

Multiplexed AUs

Overhead added

Multiplexed AUGs

STM N f

8/8/2019 BBCOM_SDH

27/66


STM-N frame

T1819950-93/D07

4

3

1

9

5

270 Ncolumns (bytes)

9 N 261 N

STM-N payload 9 rows

Section overheadSOH

Section overheadSOH

Administrative unit pointer(s)

Transmission From upper left corner to lower right corner. One row at a time

Each byte is transmitted with most significant bit first

Frame Repeated every 125 s => frame rate 8 kHz Each byte correspond to 64 kbit/s

STM 1 S ti h d (SOH)

8/8/2019 BBCOM_SDH

28/66


STM-1 Section overhead (SOH)

Regenerator Section Overhead (RSOH) terminated at regenerators

Multiplexer Section Overhead (MSOH) terminated at multiplexers

Regerator section overhead

8/8/2019 BBCOM_SDH

29/66


Regerator section overhead

A1, A2 Framing bytes. A1=hex F6, A2=hex 28.C1/J0

STM-1 Identifier / Section trace.(16-byte frame)B1 8-bit byte interleaved parity (BIP-8)

check sum on entire STM-1 (after scrambling)and stored in the next frame (before scrambling).

E1 Order wire-64 kbit/s voice channel.F1 User channel, not yet defined.D1-D3

Data communication channel (192 kbit/s)for operation and management of regene-rators.

Multiplexer section overhead

8/8/2019 BBCOM_SDH

30/66


Multiplexer section overhead

B2 3 bytes (BIP-24)check sum. Calculated onthe entire STM-1 (except RSOH) and inser-ted in the next frame.

K1,K2

Mainly for signaling related to multiplexsection protection and maintenance.

D4-D12 Data Communication Channel (576 kbit/s)

for operation and management of multi-

plexers.S1 Synchronization state.M1 Section REI (FEBE). Number of B2

bit errors detected by far end in the lastframe. Range [0-24*N] for STM-N, buttruncated at 255.

E2 Order wire for multiplex section.

8/8/2019 BBCOM_SDH

31/66

Low-order path overhead

8/8/2019 BBCOM_SDH

32/66


Low order path overhead

VC-11, VC-12, VC-2 pathoverhead : V5, J2, N2 and K4.BIP-2 2-bit interleaved check sum calculated on

the total VC-n, stored and inserted intothe next VC-n.

REI (former FEBE) Remote Error Indication. Bit which shows

if any BIP-2 errors was found in the lastreceived frame in the far end.RFI Remote Failure Indication. A failure is a

defect which persists beyond the timeallocated for protection mechanisms.

RDI (former FERF)

Remote Defect Indication. Bit which showif the far end has detected a large problem.

J2 : Low-order path Access Point Identifier.

N2 : Tandem Connection MonitorK4 : (b1-b4) Automatic Protection Switching.

(b5-b7) Reserved.(b8) Spare

BIP-2 REI RFI Signal Label RDI

1 2 3 4 5 6 7 8

Virtual Container path REI coding: 0 = 0 errors

1 = 1 or more errors

Virtual Container path Signal Label coding :

b5 b6 b7 Meaning

0 0 0 Unequipped or supervisory-unequipped

0 0 1 Equipped - non-specific (Note 1)

0 1 0 Asynchronous

0 1 1 Bit synchronous (Note 2)

1 0 0 Byte synchronous

1 0 1 Reserved for future use

1 1 0 Test signal, O.181 specific mapping (Note 3)

1 1 1 VC-AIS (Note 4)

NOTES

1 Value "1" is only to be used in cases where a mapping code is not defined in the above table. For

interworking with old equipment (i.e. designated to transmit only the values "0" and "1"), the following

conditions apply:

For backward compatibility, old equipment shall interpret any value received other than "0" as an

equipped condition.

For forward compatibility, when receiving value "1" from old equipment, new equipment shall not

generate a Signal Label Mismatch alarm.

2 In the case of a VC-12, the code "3" shall, for backward compatibility purposes, continue to be

interpreted as previously defined even if the bit synchronous mapping of 2048 kbit/s signal is not

defined anymore.

3 Any mapping defined in Recommendation O.181 which does not correspond to a mapping defined in

Recommendation G.707 falls in this category.

4 Only for networks supporting the transport of Tandem Connection signals.

V5=>

FIGURE 9-7/G.707 (03/96)

VC-2/VC-1 POH V5 byte

Overhead summary

8/8/2019 BBCOM_SDH

33/66


Overhead summary

Regenerator section Multiplekser section

End-to-end high-order path

End-to-end low-order path

TU-pointer

AU-pointer

8/8/2019 BBCOM_SDH

34/66


SDH

pointers

Pointers

8/8/2019 BBCOM_SDH

35/66


Pointers


Multiplexed TUs

Pointer added

Overhead added

Input container

Overhead added

Pointer added

Multiplexed AUs

Overhead added

Multiplexed AUGs

Pointers

8/8/2019 BBCOM_SDH

36/66


Pointers

Pointers are used to allow a flexible and dynamic alignment of VC-nswhich include compensation for phase and frequency differences betweentwo SDH net.

There are two pointer levels for 2Mb/s signals in a VC-4.

AU-4 pointer

8/8/2019 BBCOM_SDH

37/66


AU 4 pointer

1

2

3

4 H1

5

6

7

8

9

H3 H3 H3 0 - - 1

87

- -- 86

1

2

3

4

5

6

7

8

9

-

- -521

- -782

- -860

522 -

. . . .

. . . .

. . . .

. . . .

. . . .

. . . .

H2Y

1 2 3 4 5 6 7 8 9 10 270

125 s

250 s

H1 H3 H3 H3H2YY

Y 1* 1*

1* 1*

T1819190-92/d12

AUG

Negative justificationopportunity (3 bytes)

Positive justification

opportunity (3 bytes)

All 1s byte

1001SS11 (S bits are unspecified)

1*

Y

AU-4 pointer offset numbering

261*9/3 = 783 = 0 to 782

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

H1 H2 H3

T1518180-95

10 AU-4, AU-3, TU-3

ID

N

IncrementDecrement

New data flag

Negative

justificationopportunity

Positive

justificationopportunity

Negative justification

Invert 5 D-bits

Accept majority vote

SS bits AU-n/TU-ntype

Concatenation indication

1001SS1111111111 (SS bits are unspecified)


Invert 5 I-bits


NOTE The pointer is set to all "1"s when AIS occurs.

10 bit pointer value

New data flag

Enabled when at least 3 out of 4 bits match "1001"

Disabled when at least 3 out of 4 bits match "0110"

Invalid with other codes

Pointer value(b7-b16)

Normal range is:

for AU-4, AU-3: 0-782 decimal

for TU-3: 0-764 decimal

FIGURE 8-3/G.707 (03/96)

AU-n/TU-3 pointer (H1, H2, H3) coding

AU-4 pointers

8/8/2019 BBCOM_SDH

38/66


AU 4 pointers

1

2

3

4 H1

5

67

8

9

H3 H3 H3 0 - - 1

87

- -- 86

1

2

3

4

5

6

7

8

9

-

- -521

- -782

- -860

522 -

. . . .

. . . .

. . . .

. . . .

. . . .

. . . .

H2Y

1 2 3 4 5 6 7 8 9 10 270

125 s

250 s

H1 H3 H3 H3H2YY

Y 1* 1*

1* 1*

T1819190-92/d12

AUG

Negative justificationopportunity (3 bytes)

Positive justificationopportunity (3 bytes)

All 1s byte


1*

Y

AU-4 pointers

8/8/2019 BBCOM_SDH

39/66


AU 4 pointers


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

H1 H2 H3

T1518180-95

10 AU-4, AU-3, TU-3

I

DN

Increment

DecrementNew data flag

Negative

justification

opportunity

Positive

justification

opportunity


Invert 5 D-bits


SS bits AU-n/TU-ntype



Positive justification Invert 5 I-bits


NOTE The pointer is set to all "1"s when AIS occurs.

10 bit pointer value

New data flag

Enabled when at least 3 out of 4 bits match "1001"

Disabled when at least 3 out of 4 bits match "0110"

Invalid with other codes

Pointer value(b7-b16)

Normal range is:

for AU-4, AU-3: 0-782 decimal


8/8/2019 BBCOM_SDH

40/66

Possitive adjustment

8/8/2019 BBCOM_SDH

41/66


Possitive adjustment

43

1

5

9

500 s

375 s

250 s

125 s

H3H3H3H2H1

43

1

5

9

H3H3H3H2H1

4

3

1

5

9

H3H3H3H2H1

43

1

5

9

H3H3H3H2H1

1 2 3 4 5 6 7 8 9 10 270

Y Y 1* 1*

Y Y 1* 1*

Y Y 1* 1*

Y Y 1* 1*

n 1

n 1

n 1

n 1

n n n n+ 1, n+ 1

n n n n+ 1, n+ 1

n n n n+ 1, n+ 1

T1819220-92/d15

AUG

n n n n+ 1, n+ 1

Pointer value (n+ 1)

Pointer value (I-bits inverted)

Pointer value (n)

Positive justification bytes (3 bytes)

All 1s byte


Start of VC-4

Frame 1

Frame 2

Frame 3

Frame 4

1*

Y


8/8/2019 BBCOM_SDH

42/66


g j

43

1

5

500 s

375 s

250 s

125 s

H3H3H3H1

43

1

5

9

H3H3H3H1

43

1

5

9

H1

43

1

5

9

H3H3H3H1

1 2 3 4 5 6 7 8 9 10 270

9

Y Y 1*1*

Y Y 1*1*

Y Y 1*1*

Y Y 1*1*

AUG

H2

H2

H2

H2

n n n n+ 1, n+ 1n 1

n n n n+ 1, n+ 1n 2, n 1, n 1, n 1

n n n n+ 1, n+ 1n 2 n 1, n 1, n 1

n n n n

+ 1,n

+ 1

T1819240-92/d17

n

2n

1,n

1,n

1Frame 4

Frame 3

Frame 2

Frame 1

Pointer value (n 1)

Pointer value (D-bits inverted)

Pointer value (n)

Negative justification bytes (data)

All 1s byte1001SS11 (S bits are unspecified)

Start of VC-4

1*Y

TU-12 Pointer-1

8/8/2019 BBCOM_SDH

43/66


XXXXXX00

XXXXXX01

XXXXXX10

XXXXXX11

V1

V2

V3

V4

V5

500 s

375 s

250 s

125 s

26 35 107

26 35 107

26 35 107

26 35 107

104 140 428

T1518250-95

J2

N2

K4

TU-n VC-n

VC-11 VC-12 VC-2

State ofH4 byte

VC capacity (byte/500 ms)

TUVCV1V2V3V4

Tributary unitVirtual containerVC Pointer 1VC Pointer 2VC Pointer 3 (action)Reserved

NOTE V1, V2, V3 and V4 bytes are part of the TU-n and are terminated at the

pointer processor.

FIGURE 8-10/G.707 (03/96) Virtual Container mapping in multiframed Tributary Unit


00

01

11

V1 V2

V1

V2

V3

V4

T1518260-95

PTR1

PTR2

TU-11

TU-2

TU-12

Zero pointer offset location

Negative justification opportunity

Positive justification opportunity

PTR3 (action)

Reserved

(S bits specify size)

10-bit pointer value




Invert 5 D-bits



Invert 5 I-bits




NDF

I IncrementD DecrementN New Data Flag

New Data Flag Enabled when at least 3 out of 4 bits match "1001" Disabled when at least 3 out of 4 bits match "0110" Invalid with other codes

Pointer value

Normal range is:




NDF

NDF

FIGURE 8-11/G.709 (03/96) TU-2/TU-1 pointer coding

V1

105

....

139

V2

0

....

34

V3

35

....

69

V4

70

104

....

TU-12

TU-12 Pointer-2

8/8/2019 BBCOM_SDH

44/66


H4(00)

H4(01)

H4(10)

H4(11)

H4(00)

T1518280-95

(V4)

PTR (V2)

PTR (V3)

(V4)

PTR (V1)

VC-3/VC-4 POH

VC-3/VC-4 payload

VC-3/VC-4 payload

VC-3/VC-4 payload

VC-3/VC-4 payload

VC-3/VC-4 payload

9row

In H4 (XY), XY represent bits 7 and 8 of H4

FIGURE 8-13/G.707 TU-1/2 500 s multiframe indication using H4 byte

H4 bits1 2 3 4 5 6 7 8 Frame N Time-------------------------------------------------------------

X X X X X X 0 0 0 0

X X X X X X 0 1 1

X X X X X X 1 0 2

X X X X X X 1 1 3 500 s TU-n multiframe

X undefined content

FIGURE 8-14/G.707

Tributary Unit multiframe indicator byte (H4) coding sequence

8/8/2019 BBCOM_SDH

45/66


SDH

mapping and multiplexing

Multiplexing

8/8/2019 BBCOM_SDH

46/66


p g


Multiplexed TUs

Pointer added

Overhead added

Input container

Overhead added

Pointer added

Multiplexed AUs

Overhead added

Multiplexed AUGs

8/8/2019 BBCOM_SDH

47/66

STM-N pointers

8/8/2019 BBCOM_SDH

48/66


1 9

1 261

1 9

1 261

N 9 N 261

123...N123...N

T1518050-95

123 ... N

123...N123...N

AUG AUG

RSOH

MSOH

STM-N

#1 #N

STM-n Section Overhead (SOH)

8/8/2019 BBCOM_SDH

49/66


STM-4 overhead

Some bytes are repeated 4 times (for STM-4) and others only show once.

And in the latter case the byte from the first STM-1 is used.

The overhead is 36 bytes long for STM-4, but 1 byte is still 64 kbit/s.

Multiplexing of TUs 1

8/8/2019 BBCOM_SDH

50/66


TUG-3 VC-4

AA B CA B C A B CA B C

74 5 61 2 3 108 9 261

. . . .

1 86 1 86 1 86

TUG-3(A)

TUG-3(B)

TUG-3(C)

T1819120-92/d05

FIGURE 2-4/G.709

Multiplexing of three TUG-3s into a VC-4

Fixed stuff

VC-4 POH

8/8/2019 BBCOM_SDH

51/66

Mapping

8/8/2019 BBCOM_SDH

52/66



Multiplexed TUs

Pointer added

Overhead added

Input container

Overhead added

Pointer added

Multiplexed AUs

Overhead added

Multiplexed AUGs

Mapping

8/8/2019 BBCOM_SDH

53/66


In the SDH note following mappings are described :

140 Mbit/s PDH => C-4 => VC-434 Mbit/s PDH => C-3 => VC-3 => TU-3 => TUG-32 Mbit/s

2 Mbit/s can be mapped into C-12 using 3 metods:

Asynchronous (eg. PDH signals)

Bit-synchronous (not framesynchronous) (not in 03/96)Byte- synchronous (frame and speed synchronous)

2 ways of operation are defined:

Floating mode (pointers are used)Locked mode (no pointers) (not in 03/96)

Multiframed TU-12

8/8/2019 BBCOM_SDH

54/66


VC-12 mapped into

a multi-frame TU-12

TU-12 multiframe indikation

H4(00)

H4(01)

H4(10)

H4(11)

H4(00)

T1819300-92/d24

VC-3/VC-4 POH

VC-3/VC-4 payload

VC-3/VC-4 payload

VC-3/VC-4 payload

VC-3/VC-4 payload

VC-3/VC-4 payload

9row

FIGURE 3-13/G.709

An example of TU-1/2 multiframe indication using H4 byte

(the case of 500 s multiframe)

TU PTR (V1)

TU PTR (V2)

TU PTR (V3)

TU PTR (V4)

TU PTR Tributary unit pointer

TU PTR (V4)XXXXXX00

XXXXXX01

XXXXXX10

XXXXXX11

V1

V2

V3

V4

V5

500 s

375 s

250 s

125 s

26 35 107

26 35 107

26 35 107

26 35 107

104 140 428

T1518250-95

J2

N2

K4

TU-n VC-n

VC-11 VC-12 VC-2

State ofH4 byte

VC capacity (byte/500 ms)

TU

VCV1V2V3V4

Tributary unit

Virtual containerVC Pointer 1VC Pointer 2VC Pointer 3 (action)Reserved

NOTE V1, V2, V3 and V4 bytes are part of the TU-n and are terminated at the

pointer processor.

FIGURE 8-10/G.707 (03/96) Virtual Container mapping in multiframed Tributary Unit

Asynchronous

8/8/2019 BBCOM_SDH

55/66


D Data bitO Overhead (8 bit)C Justification control (6 bit)S Justification possibility (2 bit)

R Fixed stuff J2 * Low order path traceN2 * Tandem Connection MonitoringK4 * Automatic Protection Switching

Additional RDI information

1023 databit / 500 s

Used e.g. for PDH signals

* From ITU-T G707 (03/96)

2 Mbit/s mapping - asynchronous

T1523020-96

V 5

R R R R R R R R

R R R R R R R R

J 2

C1 C2 O O O O R R

R R R R R R R R

N 2

R R R R R R R R

K 4

C1 C2 R R R R R S1

S2 D D D D D D D

C1 C2 O O O O R R

R R R R R R R R

32 bytes

32 bytes

32 bytes

31 bytes

140bytes

Data bit

Fixed stuff bit

Overhead bit

Justification opportunity bit

Justification control bit

D

R

O

S

C

FIGURE 10-8/G.707 Asynchronous mapping of 2048 kbit/s tributary

8/8/2019 BBCOM_SDH

56/66

Asynchronous 140 Mbit/s

8/8/2019 BBCOM_SDH

57/66


T1518350-95

J1

B3

C2

G1

F2

H4

F3

K3N1

5

1

3

20 blocks of 13 bytes

270 bytes

261 bytes

VC-4

AU-413 bytes1 byte

SOH

SOH

AU-4 PTR

STM-1

VC-4POH

PTR Pointer

FIGURE 10-2/G.707 (03/96)

Multiplexing of VC-4 into STM-1 and

block structure of VC-4 for

asynchronous mapping of 139 264 kbit/s

W X Y Y Y

Y YX Y X

YY

YY

W

X

Y

Z

Z

YX

X

Y

Y

T1522990-96

1

96 D 96 D 96 D 96 D 96 D

96 D 96 D 96 D 96 D 96 D

96 D 96 D 96 D 96 D 96 D

96 D 96 D 96 D 96 D 96 D

DDDDDDDD

CRRRRROO

RRRRRRRR

DDDDDDSR

12 bytes

POH

Data bit

Fixed stuff bit

Overhead bit

Justification opportunity bit

Justification control bit

NOTE This figure shows one row of the nine-row VC-4 container structure.

D

R

O

S

C

FIGURE 10-3/G.707 (03/96)

Asynchronous mapping of 139 264

kbit/s tributary into VC-4

Mapping of ATM cells

8/8/2019 BBCOM_SDH

58/66


J1

B3

C2

G1

F2

H4

F3

K3

N1

ATM Cell

53 octets

....

....

VC-4/VC-3

VC-4/VC-3 POH

J1

B3

C2

G1

F2

H4

F3

K3

N1

ATM Cell

53 octets

....

VC-4-Xc

VC-4-Xc POH

FixedStuff

X-1 X x 260 bytes

....

Mapping ATM cellsinto a VC-4

Mapping ATM cells intoa concatinated VC-4

(VC-4-Xc)

ATM bytes are alignedCells may cross frames

Optical standards 1

8/8/2019 BBCOM_SDH

59/66


Application Intra-Inter-office

officeShort-haul Long-haul

Source nominalwavelength (nm)

1310 1310 1550 1310 1550

Type of fibre Rec. G.652 Rec. G.652 Rec. G.652 Rec. G.652 Rec. G.652Rec. G.654

Rec. G.653

Distance (km)a) 20 15 40 80

STM-1 I-10 S-1.10 S-1.20 L-1.10 L-1.20 L-1.30

STM level STM-4 I-40 S-4.10 S-4.20 L-4.10 L-4.20 L-4.30

STM-16 I-16 S-16.1 S-16.2 L-16.1 L-16.2 L-16.3

a) These are target distances to be used for classification and not for specification.

TABLE 1/G.957

Classification of optical interfaces based on applicationand showing application codes

Parameters for STM-16 interface

8/8/2019 BBCOM_SDH

60/66


Unit Values

Digital signalNominal bit rate kbit/s

STM-16 according to Recommendations G.707 and G.9582 488 320

Application code (Table 1) I-16 S-16.1 S-16.2 L-16.1 L-16.2 L-16.3

Operating wavelength range nm 1266a)-1360 1260a)-1360 1430-1580 1280-1335 1500-1580 1500-1580

Transmitter at reference point S

Source type MLM SLM SLM SLM SLM SLM

Spectral characteristics

maximum RMS width () nm 4

maximum 20 dB width nm 1 < 1b) 1 < 1

b) < 1b)

minimum side mode suppression ratio

dB 30 30 30 30 30

Mean launched power

maximum dBm 30 00 00 +3 +3 +3

minimum dBm 10 50 50 2 2 2

Minimum extinction ratio dB 8.2 8.2 8.2 8.2 8.2 8.2

Optical path between S and R

Attenuation rangec) dB 0-7 0-12 0-12 10-24e) 10-24e) 10-24e)

Maximum dispersion ps/nm 12 NA b) NA 1200-1600b),d) b)

Minimum optical return loss ofcable plant at S, including anyconnectors

dB 24 24 24 24 24 24

Maximum discrete reflectance

between S and R

dB 27 27 27 27 27 27

Receiver at reference point R

Minimum sensitivityc) dBm 18 18 18 27 28 27

Minimum overload dBm 30 00 00 9 90 9

Maximum optical path penalty dB 1 1 1 1 2 1

Maximum reflectance ofreceiver, measured at R

dB 27 27 27 27 27 27

Multiplex-Section Protection

8/8/2019 BBCOM_SDH

61/66


A number of MSP architectures exists of which two is shown:

T1508790-92/d33

0

1Workingchannel 1

Permanent

bridgeSelector

Working

section 1

FIGURE A.1/G.783

MSP Switch 1 + 1 architecture example(shown in released position)

Protectionsection (0)

T1508800-92/d34

0

1

2

15

15

0

1

2

Working

channel 1


Selector

Workingsection 1

Working

section 2Working

channel 2

Extra

traffic

channel

(15)

Null

channel (0)

Bridge

FIGURE A.2/G.783

MSP Switch 1 : n architecture example(shown in released position)

1+ 1 protection

8/8/2019 BBCOM_SDH

62/66


T1508790-92/d33

0

1Workingchannel 1

Permanentbridge

Selector

Workingsection 1

FIGURE A.1/G.783

MSP Switch 1 + 1 architecture example(shown in released position)


1:n protection

8/8/2019 BBCOM_SDH

63/66


T1508800-92/d34

0

1

2

15

15

0

1

2

Workingchannel 1


Selector

Workingsection 1

Workingsection 2Working

channel 2

Extratrafficchannel(15)

Nullchannel (0)

Bridge

FIGURE A.2/G.783

MSP Switch 1 : n architecture example(shown in released position)

STM-n Signal Composition

8/8/2019 BBCOM_SDH

64/66


Composition of an STM-n signal carrying a 140 Mbit/s PDH signal

C-4 => VC-4 => STM-n

Clock 1Clock hierarchy:

8/8/2019 BBCOM_SDH

65/66


T1816900-92/d26

PRC Primary reference clock

G.811

PRC

G.812

node

clock

G.812

node

clock

G.812

node

clock

G.812

node

clock

G.812

node

clock

G.812

node

clock

FIGURE 6-2/G.803

Synchronisation network architecture inter-node distribution

T1816890-92/d25

Synchronisationlink(s)

Node

boundary

SDH

network

element

clock

SDH

network

element

clock

Nodeclock

SDH

network

element

clock

SDH

network

element

clock

Distribution to other

G.81s clocks

outside the node

a)

a)

a)

a)

FIGURE 6-1/G.803

Synchronisation network architecture intra-node distribution

Timing only.a)

Clock hierarchy:

Primary reference clock (PRC)Slave (transit)Slave (local)SDH element clock

Clock 2

8/8/2019 BBCOM_SDH

66/66


The clock of a SDH Network Elementcan be synchronized in two ways:

a) Synchronization to an incoming STM-N line.

b) Synchronization to a Node clock which is synchronized to a STM-N signal,a 2048 kbit/s signal or a 2048 kHz signal.

BBCOM_SDH

Documents

Transcript of BBCOM_SDH