Training Pdh Sdh Dwdm

(1)

(2)

Introduction

Telecommunications –

Communication over distance

Transmission networks deal with getting

(3)

Transmission Technologies

FDM – Frequency division multiplexing.

TDM – Time Division Multiplexing.

(4)

Time Division Multiplexing

1 1 1

1 1

2 2 2

2 2

3 3 3

3 3

4 4 4

4 4

4 3 2

1 4 3

2 1

Low order signals

(5)

Dense Wave Division Multiplexing

One

Wavelength

(6)

(7)

Dense Wave Division Multiplexing

DWDM Signal

λ1

λ2

λ3

λ4

λ5

λ6

λ7

λ8

λ1

λ2

λ3

λ4

λ5

λ6

λ7

λ8

(8)

Primary Rate Multiplexing

Sampling

Quantising

Encoding

Multiplexing

Analogue Signal

(9)

Primary Rate Multiplexing

Analogue signal

(10)

Primary Rate Multiplexing

Quantising

Encoding

10110010110010010101010

(11)

Primary Rate Multiplexing

0 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031

2MBit/s

64KBit/s

0 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031

31 Channels

Framing

0 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031

15 Channels

Framing

Signalling

31 C

h

ann

el

30 Ch

an

n

el

(12)

PDH

Plesiochronous Digital Hierarchy

Plesiochronous – “Almost Synchronous”

Multiplexing of 2Mbit/s signals into higher order multiplexed signals.

Laying cable between switch sites is very expensive.

Increasing traffic capacity of a cable by increasing bit rate.

4 lower order signals multiplexed into single higher order signal at

each level.

(13)

PDH

28

8

34

140

565

140

34

8

82

(14)

PDH

2

34

140

565

140

34

2

(15)

PDH Limitations

Synchronisation

TX

RX

1

0

0 The data is transmitted at regular

intervals. With timing derived from

the transmitters oscillator.

The data is sampled at the same

rate as it is being transmitted.

(16)

PDH Limitations

Synchronisation

TX

RX

1

0

0 The data is transmitted at regular

intervals. With timing derived from

the transmitters oscillator.

The data is sampled at a slower

rate than the transmitter.

These bits are

missed at the

receiver end.

(17)

PDH Limitations

Synchronisation

TX

RX

1

0

0 The data is transmitted at regular

intervals. With timing derived from

the transmitters oscillator.

The data is sampled at a faster

rate than the transmitter.

These bits are

sampled twice at

the receiver end.

(18)

PDH Limitations

Synchronisation

TX

RX

TX

DE

MUX

DE

MUX

HO

TX

HO

TX

HO

RX

HO

RX

Timing

extraction

Timing

extraction

(19)

PDH Limitations

Synchronisation

bit rate

adaption

bit rate

adaption

4

3

2

1

3

2

1 ‘fast’ incoming

2Mbit/s channel

‘slow’ incoming

2Mbit/s channel

J

3

2

1 J

J

4

3

2

1 Justification

bits

Justification

bits

Master

oscillator

8Mbit/s

(20)

PDH Limitations

Mux Mountain

2

8

34

140

565

140

34

8

82 Add / Drop

Increased equipment requirements

Increased space on site.

(21)

PDH Limitations

Lack Of Traffic Resilience

140

565

140 Traffic Lost

Traffic Lost

(22)

PDH Limitations

Limited Network Management

140

565

140 Traffic Lost

Traffic Lost

DCN

!

Alarm reported.

No diagnosis tools available.

Maintenance staff sent to site.

(23)

PDH Limitations

No Mid-Fibre Meet

140

565

140

(24)

SDH

(25)

SDH – Global Networks

European bit rates

64Kb/s

(PCM)

x32

_2Mb/s

x4

_8Mb/s

x4

_34Mb/s

x4

_140Mb/s

x4

_565Mb/s

North American bit rates

1.5Mb/s

x24

x4

_6Mb/s

x7

_45Mb/s



_



X

Not supported

in SDH.

Non standard

X

1

st

_Order

₂

nd

_Order

_{3rd Order}

_{4th Order}

E1

_E2

_E3

_E4

(26)

SDH – Network Topologies

Line Systems

(27)

SDH – Network Topologies

Line Systems

Terminal

(28)

SDH – Network Topologies

Ring Systems

ADM

(29)

STM-1

Pointers

Overheads

(30)

STM-1

Pointers

Overheads

Payload

9 Bytes

261 Bytes

270 Bytes

(31)

STM-1

Pointers

Overheads

Payload

9 Bytes

261 Bytes

270 Bytes

1 2 3 4 5 6 7 8 9 ₀1 1₁ 1₂ 26₈ 26₉ 27₀ 21 61 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 242₈ 242₉ 24₃₀ 27 1 54 1 81 1 1 0 81 1 3 51 1 6 21 1 8 91

(32)

STM-1 Overheads

Repeater Section Overheads

Multiplex Section Overheads

AU Pointers

3 Bytes

1 Byte

5 Bytes

(33)

STM-1 Overheads

ADM

SDH

Regen

SDH

Regen

SDH

ADM

(34)

STM-1 Overheads

ADM

SDH

Regen

SDH

Regen

SDH

ADM

SDH

(35)

STM-1 Overheads

ADM

SDH

Regen

SDH

Regen

SDH

ADM

SDH

(36)

STM-1 Overheads

ADM

SDH

Regen

SDH

Regen

SDH

ADM

SDH

(37)

STM-1 Overheads

ADM

SDH

Regen

SDH

Regen

SDH

ADM

SDH

POH

RS

(38)

STM-1 RS Overheads

A1

A2

J0

X X

B1

MD MD

E1

MD

F1

X X

D1

MD MD

D2

MD

D3

Multiplex Section Overheads

AU Pointers

X – Reserved bytes MD – Media dependent

(39)

STM-1 RS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

Multiplex Section Overheads

AU Pointers

The A1 & A2 bytes are used for frame

(40)

STM-1 RS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

Multiplex Section Overheads

AU Pointers

The J0 byte is used to carry the RS Path

Trace. This is a

repetitively transmitted string used to identify the transmitting node.

(41)

SDH Path Trace

ADM

SDH

London

Paris

“London”

“Paris”

(42)

SDH Path Trace

ADM

SDH

London

Paris

“London”

“Paris”

“London”

(43)

SDH Path Trace

ADM

SDH

London

Paris

“London”

“Paris”

“London”

“Paris”



“London”



(44)

SDH Path Trace

ADM

SDH

London

Paris

!

“London”

“Paris”

“London”

“Amsterdam”

“London”



X

(45)

STM-1 RS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

Multiplex Section Overheads

AU Pointers

The B1 byte is used for

parity error checking.

It carries the parity of the complete previous

(46)

STM-1 RS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

Multiplex Section Overheads

AU Pointers

The E1 byte provides a 64Kbit/s channel that

can be used to carry voice for engineering

order wire use. As this

is in the RS overhead this channel can be accessed at any node.

(47)

SDH EOW

ADM

SDH

Regen

SDH

Regen

SDH

ADM

(48)

STM-1 RS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

Multiplex Section Overheads

AU Pointers

The F1 byte is reserved for user purposes.

(49)

STM-1 RS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

Multiplex Section Overheads

AU Pointers

The D1, D2, & D3 bytes provides a 192Kbit/s channel that

is used as a data

communications channel between

nodes for management purposes.

(50)

SDH Management

ADM

SDH

Regen

SDH

Regen

SDH

ADM

SDH

Network Management Centre

DCN Network

DCC Channels DCC Channels DCC Channels DCN Connection DCN Connection Gateway Node Gateway Node

(51)

STM-1 MS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

B2

K1

K2

D4

D5

D6

D7

D8

D9

D10

D11

D12

S1

Z1

Z2

M1 E2

X X

Repeater Section Overheads

AU Pointers

(52)

STM-1 MS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

B2

K1

K2

D4

D5

D6

D7

D8

D9

D10

D11

D12

S1

Z1

Z2

M1 E2

X X

Repeater Section Overheads

AU Pointers

The B2 byte allows for

parity error checking

within the MS overhead. Parity is computed from the previous frame with the exception of the RS overheads.

(53)

STM-1 MS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

B2

K1

K2

D4

D5

D6

D7

D8

D9

D10

D11

D12

S1

Z1

Z2

M1 E2

X X

Repeater Section Overheads

AU Pointers

The K1 & K2 bytes are for used for automatic

protection switching.

The are used to control the switches that occur on the network.

(54)

SDH Network Resilience

ADM

Active path

Standby path

(55)

SDH Network Resilience

ADM

Active path

Standby path

(56)

SDH Network Resilience

ADM

Active path

Standby path

Network Management

Centre

Switch

(57)

STM-1 MS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

B2

K1

K2

D4

D5

D6

D7

D8

D9

D10

D11

D12

S1

Z1

Z2

M1 E2

X X

Repeater Section Overheads

AU Pointers

The Dx bytes are for used for a DCC

channel within the MS

overhead.

576Kbit/s are available for communication within this channel.

(58)

STM-1 MS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

B2

K1

K2

D4

D5

D6

D7

D8

D9

D10

D11

D12

S1

Z1

Z2

M1 E2

X X

Repeater Section Overheads

AU Pointers

The S1 byte is used for

synchronisation

messaging. It denotes the quality level of the synchronisation that can be derived from this incoming signal.

(59)

SDH Network Synchronisation

Primary

reference

Secondary

reference

ADM

(60)

SDH Network Synchronisation

Primary

reference

Secondary

reference

ADM

(61)

SDH Network Synchronisation

Primary

reference

Secondary

reference

ADM

!

(62)

SDH Network Synchronisation

Primary

reference

Secondary

reference

ADM

!

ADM

(63)

STM-1 MS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

B2

K1

K2

D4

D5

D6

D7

D8

D9

D10

D11

D12

S1

Z1

Z2

M1 E2

X X

Repeater Section Overheads

AU Pointers

The Z1 and Z2 bytes currently have no allocated function.

(64)

STM-1 MS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

B2

K1

K2

D4

D5

D6

D7

D8

D9

D10

D11

D12

S1

Z1

Z2

M1 E2

X X

Repeater Section Overheads

AU Pointers

The M1 byte is used as a remote error

(65)

Remote Error Indication

ADM

SDH

Regen

SDH

Regen

SDH

ADM

SDH

B2 error detected

Multiplex section

(66)

Remote Error Indication

ADM

SDH

Regen

SDH

Regen

SDH

ADM

SDH

B2 error detected

MS-REI

received _generatedMS-REI

Multiplex section

(67)

STM-1 MS Overheads

A1

A2

J0

B1

E1

F1

D1

D2

D3

B2

K1

K2

D4

D5

D6

D7

D8

D9

D10

D11

D12

S1

Z1

Z2

M1 E2

X X

Repeater Section Overheads

AU Pointers

The E2 byte provides an EOW channel within the MS overhead.

(68)

SDH Pointers

Repeater Section Overheads

AU Pointers

(69)

SDH Pointers

Repeater Section Overheads

AU Pointers

Multiplex Section Overheads

Repeater Section Overheads

AU Pointers

Multiplex Section Overheads

Payload area

(70)

SDH Pointers

Repeater Section Overheads

AU Pointers

Multiplex Section Overheads

Repeater Section Overheads

AU Pointers

Multiplex Section Overheads

Payload area

(71)

SDH Pointers

Repeater Section Overheads

AU Pointers

Multiplex Section Overheads

Repeater Section Overheads

AU Pointers

Multiplex Section Overheads

Payload area

(72)

SDH Pointers

Repeater Section Overheads

AU Pointers

Multiplex Section Overheads

Repeater Section Overheads

AU Pointers

Multiplex Section Overheads

Payload area

(73)

SDH Pointers

H1 H1 H1 H2 H2 H2 H3 H3 H3

(74)

SDH Pointers

H1 H1 H1 H2 H2 H2 H3 H3 H3

(75)

SDH Pointers

H1 H1 H1 H2 H2 H2 H3 H3 H3

(76)

SDH Pointers

H1 H1 H1 H2 H2 H2 H3 H3 H3

NDF NDF NDF NDF S

S

I

D

I

D

I

D

I

D

I

D

(77)

SDH Pointers

H1 H1 H1 H2 H2 H2 H3 H3 H3

(78)

Past STM-1

Pointers

Overheads

Payload

144 Bytes

4176 Bytes

4320 Bytes

9 Bytes

STM16 Frame

(79)

Past STM-1

Optical

Electrical / Optical

Electrical

Medium

40Gbit/s

STM-256 (future)

10Gbit/s

STM-64

2.5Gbit/s

STM-16

622Mbit/s

STM-4

155Mbit/s

STM-1

140Mit/s

E4

34Mit/s

E3

2Mit/s

E1

Bit rate

Signal

(80)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

AU-4

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

STM-N

Mapping

Aligning

Multiplexing

TUG-2

TUG-3

AUG

x4

x3

x1

x7

x3

xN

(81)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

C-3

AU-3

C-2

C-12

C-11

x3

The Container is the basic element of SDH. Payload signals that are to be

transported across the SDH layer are mapped into the appropriate container. 1.5M maps into a C-11 2M maps into a C-12 6M maps into a C-2 34M maps into a C-3 45M maps into a C-3 140M maps into a C-4

(82)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

C-2

C-12

C-11

VC-11

VC-12

VC-2

VC-3

x3

Overhead bytes collectively known as the Lower Order

Path Overhead are added to

the container to form a Virtual

(83)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

C-2

C-12

C-11

VC-11

VC-12

VC-2

VC-3

x3

The VC-11/12/2 POH is comprised of :

V5 - Indication and error

monitoring. J2 - Path indication N2 - Tandem connection monitoring K4 - Automatic protection switching

(84)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

C-2

C-12

C-11

VC-11

VC-12

VC-2

VC-3

x3

The VC-3/4 POH is comprised of : J1 - Path indication B3 - Quality monitoring C2 - Container format G1 - Transmission error acknowledgment F2 - Maintenance H4 - Superframe indication F3 - Maintenance K3 - Automatic protection switching N1 - Tandem connection monitoring

(85)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

x3

A Pointer is added to the

Virtual Container to create a Tributary Unit.

This pointer functions in the same way as the pointer within the section overheads but is applied at a lower level and should not be confused with the higher level pointer. This lower level pointer is known as the TU Pointer

(86)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

TUG-2

x4

x3

Four of the TU-11 Tributary

Units can be multiplexed

together to create A Tributary

(87)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

TUG-2

x4

x3

Alternatively three of the

TU-12s can be multiplexed

(88)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

TUG-2

x4

x3

x1

x3

Or the last way to construct the TUG-2 is to use a single

(89)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

TUG-2

TUG-3

x4

x3

x1

x7

x3

In a typical lower order SDH network carrying 2M traffic 7

TUG-2s will be multiplexed

(90)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

TUG-2

TUG-3

x4

x3

x1

x7

x3

Alternatively if the network is carrying 34M or 45m traffic the

TUG-3 can be created from a

(91)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

TUG-2

TUG-3

x4

x3

x1

x7

x3

3 TUG-3s can be multiplexed together to create a VC-4. When this is created another

layer of path overhead is added. This is known as the

(92)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

AU-4

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

TUG-2

TUG-3

x4

x3

x1

x7

x3

A single VC-4 will have a pointer added to create an

Administrative Unit, known

(93)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

AU-4

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

TUG-2

TUG-3

AUG

x4

x3

x1

x7

x3

The Administrative Unit

Group is created when

multiplexing several

Administrative Units.

Using this route through the hierarchy only one AU-4 is needed to create the AUG, no

processing is performed or overhead added.

(94)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

AU-4

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

STM-N

TUG-2

TUG-3

AUG

x4

x3

x1

x7

x3

xN

To create the SDH signal several AUGs are multiplexed

together with the section overheads added to create the

STM-N signal.

For example, one AUG would be used in an STM-1, whereas

sixteen AUGs would be used to create an STM-16 signal

(95)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-4

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

STM-N

TUG-2

TUG-3

AUG

x4

x3

x1

x7

x3

xN

There is an alternative way to create the signal, although the

one shown here is typically used. The alternative route is

mainly used when interconnecting with SONET

networks or for SDH radio applications where lower bit rate STM-0 / OC-1s are used

as the building block instead of STM-1

(96)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-4

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

STM-N

TUG-2

TUG-3

AUG

x4

x3

x1

x7

x3

xN

Seven TUG-2s are multiplexed together to form a VC-3. This stage also adds a High Order

(97)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

AU-4

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

STM-N

TUG-2

TUG-3

AUG

x4

x3

x1

x7

x3

xN

A pointer is added to the VC-3 to create an AU-3. This pointer

(98)

SDH Hierarchy

C-4 140M

45M

34M

6M

2M

1.5M

VC-3

C-3

VC-4

AU-3

AU-4

C-2

C-12

C-11

VC-11

TU-11

VC-12

TU-12

VC-2

TU-2

VC-3

TU-3

STM-N

TUG-2

TUG-3

AUG

x4

x3

x1

x7

x3

xN

Three AU-3s can be multiplexed together to form an AUG if an STM-1 or higher

is going to be created. The AUG then has the section

(99)

DWDM Within The Network

ADM

Site D

Sit

e

C

Site A

Sit

e

B

(100)

DWDM Within The Network

Site D

Sit

e

C

Site A

Network

1 Site F

S

ite

E

Network

2 ADM

ADM

S

ite

B

ADM

(101)

DWDM Within The Network

Site D

Site C

Site A

Network

1 Site F

Site E

Network

2 Site B

ADM

(102)

Protocol Independent

DWDM networks are protocol independent.

They transport wavelengths of light and do not operate at

the protocol layer.

SDH

SONET

Ethernet

Digital Video

….

(103)

DWDM Amplifiers

Re

d Am

p

lifi

er

λ1

λ2

λ3

λ4

λ5

λ6

λ7

λ8

λ1

λ2

λ3

λ4

λ5

λ6

λ7

λ8

DWDM Co

up

le

r

B

lue

Am

p

lifi

er

DWDM Co

uple

r

B

lue

Am

p

lifi

er

Re

d Am

p

lifi

er

Blue direction

Red direction

(104)

DWDM Equalisation

(105)

DWDM Equalisation

R

ed Am

p

lifi

er

λ1

λ2

λ3

λ4

λ5

λ6

λ7

λ8

DWDM Co

up

le

r

ADM _Or _High der Lo w O rder T X T X R X R X Fib re M a na ge m ent F ra m e E lect rica l/Fibre M a n a gem ent F ra m e ADM _Or _High der Lo w O rder T X T X R X R X Fib re M a na ge m ent F ra m e E lect rica l/Fibre M a n a gem ent F ra m e F ibr e Ma na g em en t F ra m e Variable Optical Attenuator

(106)

(107)

(108)

Polarisation Mode Dispersion

While a light pulse is not itself

polarised, it consists of two

perpendicularly polarised

components.

(109)

Polarisation Mode Dispersion

An imperfectly shaped core can affect one of the

components of the pulse

Impurities within the core can delay the arrival of

one of the components.

(110)

Four Wave Mixing

195.975 196 196.025 196.05 196.075 196.1 196.125 196.15 196.175 Frequency (THz) P o w er

With two wavelength within the fibre, two additional wavelengths are generated.

f

₍₁₂₃₎

= f

₁

+f

₂

-f

₃ DWDM channel 1528.77nm ( f₁ ) DWDM channel 1529.16nm ( f2 ) f₂₂₁ f₁₁₂

(111)

Four Wave Mixing

195.9 195.9 195.9 196 196 196 196 196.1 196.1 196.1 196.1 196.2 196.2 196.2 196.2 Frequency (THz) P o w er DWDM Channels FWM Channels DWDM channel 1528.77nm ( f₃ ) DWDM channel 1529.16nm ( f₂ ) DWDM channel 1529.55nm ( f₁ ) f₃₂₁ f₃₃₁ f₃₃₂ f₃₃₁, f₂₃₁ f₁₃₂ f₃₁₂ f₂₂₃ f₁₁₂ f₁₂₃ f₂₁₃ f₁₁₃

(112)