SIX MONTH INDUSTRIAL TRAINING REPORT

ON

“Installation, commissioning & operation of SDH equipment; STM-1(Siemen)”

COMPLETED AT

REGIONAL TELECOM TRAINING CENTER RAJPURA(An ISO 9001:2008 Certified Institute)

Punjab Telecom Circle

SUBMITTED IN THE PARTIAL FULFILLMENT FOR AWARD OF DEGREE OF BACHELOR OF TECHNOLOGY

IN ELECTRONICS AND COMMUNICATION

BySukhbir Singh

UNIV. Roll No. 90690472682-L

DEPARTMENT OF ELECTRONICS AND COMMUNICATION

SHAHEED UDHAM SINGH COLLEGE OF ENGG. & TECH.

TANGORI(MOHALI)

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CONTENTS

Company profile

Preface

Acknowledgement

1 INTRODUCTION TO OPTICAL FIBRE CABLE.......................................................8

FIBRE OPTICS :..............................................................................................................8

1.1 ADVANTAGES OF FIBRE OPTICS :..................................................................8

1.2 APPLICATION OF FIBRE OPTICS IN COMMUNICATIONS :........................8

1.3 Transmission Sequence :........................................................................................9

1.4 PRINCIPLE OF FIBRE OPTICS...........................................................................9

1.5 PROPAGATION OF LIGHT THROUGH FIBRE...............................................10

1.6 FIBRE TYPES.....................................................................................................11

1.7 OFC Splicing........................................................................................................11

1.8 Fibre Splicing.......................................................................................................12

2 INTRODUCTION TO TRANSMISSION SYSTEM.................................................14

2.1 MULTIPLEXING TECHNIQUES.......................................................................14

2.2 Basic Requirements For PCM System..................................................................15

2.3 OVERVIEW OF SDH..........................................................................................15

2.3.1 The main problems of PDH systems are:................................................................16

2.3.2 SDH Advantages to Network Providers..................................................................17

2.3.3 SDH Rates...............................................................................................................18

2.3.4 SDH Hierarchy:.......................................................................................................18

2.3.5 The STM-1 Frame Format.......................................................................................19

2.3.6 Section overheads:...................................................................................................20

3 INSTALLATION AND COMISSIONING OF STM-1 (SIEMEN)........................22

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3.1 Block Diagram Of Transmission System..............................................................22

3.2 STM-1..................................................................................................................23

3.2.1 Key Features Of STM-1..........................................................................................23

3.3 STM-1 Equipment (Siemen).................................................................................24

3.4 MOTHERBOARD CARD...................................................................................24

3.5 IC1.1-2G CARD...................................................................................................25

3.6 STM-DUAL.........................................................................................................26

3.7 4E/FE....................................................................................................................26

3.8 E3DS3..................................................................................................................27

3.9 21E120, 21E75 cards............................................................................................27

3.10 Commissioning of STM-1(Siemen)..................................................................27

3.10.1 EQUIPMENT..........................................................................................................28

3.10.2 Date and Time..........................................................................................................28

3.10.3 Inventories...............................................................................................................28

3.10.4 Security....................................................................................................................29

3.10.5 Management............................................................................................................29

3.10.6 Synchronisation.......................................................................................................29

4 CONFIGURATION APPLICATION AND PERFORMANCE..................................30

4.1 Network Topologies.............................................................................................30

4.1.1 Point to point topology............................................................................................30

4.1.2 Ring topology..........................................................................................................31

4.2 Automatic Protection Switching (APS)................................................................31

4.2.1 Linear protection......................................................................................................31

4.2.2 Ring protection........................................................................................................32

Unidirectional rings...............................................................................................................32

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Bi-directional rings................................................................................................................33

4.3 Cross-Connection.................................................................................................33

5 ETHERNET ON SDH.................................................................................................36

5.1 Various Features of the Next Generation SDH.....................................................36

6 RESULT AND CONCLUSION................................................................................40

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Company profile

Regional telecom training centre(An ISO Certified Institute)

PUNJAB TELECOM CIRCLE

INTRODUCTION RTTC Rajpura was established on 01.12.75 in a rented building belonging to Kasturba

Sewa Mandir Trust in Rajpura. It has been shifted at New RTTC Complex, Neelpur Village,

Rajpura town w.e.f. 26.7.2004. It is situated on Patiala bye pass road near Liberty Chowk. Rajpura

is situated on the main line from Delhi to Amritsar at a distance of 230 Kilometers from Amritsar

as well as Delhi and 30 Kilometers from Ambala. The RTTC Complex includes Academic &

Administrative block, staff quarters, Inspection Quarters, Student Centre and Three Hostels. The

total Trainee capacity of these Hostels is 220. The entire campus is spread over 20 acres of land.

The built up area of RTTC Complex is 9700 Sq.Mtrs. The campus is situated away from the town

and is well suited for educational institution. The campus is extremely beautiful and the ambience

rejuvenating.

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PREFACE

We cannot achieve anything worthwhile in the field of technical education until or unless

theoretical education acquired in classroom is effectively wedded to its practical approach that is

taking place in the modern industries and other means of technical application, the technical

education is of equal proportions of practical and theoretical study. The six month training taken at

the RTTC Rajpura as a part of my practical study was a wonderful learning experience for me.

I was fortunate enough to see the infrastructure built by BSNL for the service of trainee. In

the period of training I was able to interact with many trainees which enhance my communication

skill as a part of whole.

I also observed fiber splicing and STM -1 operation and maintenance in transmission, in

the RTTC during project session of my training. Further the experience of working in a

competitive environment was also a major boon.

This report is a brief of learning experience at RTTC in transmission. In transmission

section STM-1 (SDH based equipment) installation & maintenance gives provide basis for

understanding of higher order multiplexing equipments.

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ACKNOWLEDGEMENT

I acknowledge my gratitude and thank to all the well knowledge persons for giving me

opportunity to avail all the best facilities available at this telecom centre through which I have

gained knowledge thinking so as too just in the environment suitable for harmonic adjustment. I

am grateful to the following persons for various help rendered by them during the training period.

Mr. R.S SANDHU(D.E)who transferred to me his innumerable knowledge of

Transmission. He was always there to address our queries and give his advice. His kind and

teaching behavior is really appreciative.

Mr. J.S MALIK (SR. SDE) He gives me his precious time even he was too busies but

never denial me at any cost. He empathizes on basic concept and built my basis for SDH

technology. He is available to me at any time for any kind of problem.

Mr. Rajesh Goel (JTO) From whom I learnt tips of the SDH and PDH technology. I

complete this project under their unforgettable guidance. His way of conduct is really appreciative.

And all other faculties and employs who help me to complete this project and without their

help this may not be possible.

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1 INTRODUCTION TO OPTICAL FIBRE CABLE

FIBRE OPTICS :

Optical Fibre is new medium, in which information (voice, Data or Video) is transmitted

through a glass or plastic fibre, in the form of light, following the transmission sequence give

below :

(1) Information is encoded into electrical signals.

(2) Electrical signals are converted into light signals.

(3) Light travels down the fibre.

(4) A detector changes the light signals into electrical signals.

(5) Electrical signals are decoded into information.

1.1 ADVANTAGES OF FIBRE OPTICS :

Fibre Optics has the following advantages :

(I) Optical Fibres are non conductive (Dielectrics)

(II) Electromagnetic Immunity :

(III) Large Bandwidth (> 5.0 GHz for 1 km length)

(IV) Low Loss (5 dB/km to < 0.25 dB/km typical)

(v) Small, Light weight cables.

(vi) Available in Long lengths (> 12 kms)

(vii) Security

(viii) Security - Being a dielectric

(ix) Universal medium

1.2 APPLICATION OF FIBRE OPTICS IN COMMUNICATIONS :

Common carrier nationwide networks.

Telephone Inter-office Trunk lines.

Customer premise communication networks.

Undersea cables.

High EMI areas (Power lines, Rails, Roads).

Factory communication/ Automation.

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Control systems.

1.3 TRANSMISSION SEQUENCE :

(1) Information is Encoded into Electrical Signals.

(2) Electrical Signals are Coverted into light Signals.

(3) Light Travels Down the Fiber.

(4) A Detector Changes the Light Signals into Electrical Signals.

(5) Electrical Signals are Decoded into Information.

- Inexpensive light sources available.

- Repeater spacing increases along with operating speeds because low loss fibres are

used at high data rates.

Figure 1.1: Block Diagram of Transmission Of Info. In OFC System

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1.4 PRINCIPLE OF FIBRE OPTICS

Total Internal Reflection - The Reflection that Occurs when a Ligh Ray Travelling in One

Material Hits a Different Material and Reflects Back into the Original Material without any Loss of

Light.

Speed of light is actually the velocity of electromagnetic energy in vacuum such as space.

Light travels at slower velocities in other materials such as glass. Light travelling from one

material to another changes speed, which results in light changing its direction of travel. This

deflection of light is called Refraction.

The amount that a ray of light passing from a lower refractive index to a higher one is bent

towards the normal. But light going from a higher index to a lower one refracting away from the

normal,

1.5 PROPAGATION OF LIGHT THROUGH FIBRE.

The optical fibre has two concentric layers called the core and the cladding. The inner core

is the light carrying part. The surrounding cladding provides the difference refractive index that

allows total internal reflection of light through the core. The index of the cladding is less than 1%,

lower than that of the core. Typical values for example are a core refractive index of 1.47 and a

cladding index of 1.46. Fibre manufacturers control this difference to obtain desired optical fibre

characteristics.

Figure1.2 : light travelling through a fibre

Light injected into the fibre and striking core to cladding interface at grater than the critical

angle, reflects back into core, since the angle of incidence and reflection are equal, the reflected

light will again be reflected. The light will continue zigzagging down the length of the fibre.

Light striking the interface at less than the critical angle passes into the cladding, where it is

lost over distance. The cladding is usually inefficient as a light carrier, and light in the cladding

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becomes attenuated fairly. Propagation of light through fibre is governed by the indices of the core

and cladding by Snell's law.

Such total internal reflection forms the basis of light propagation through a optical fibre.

This analysis consider only meridional rays- those that pass through the fibre axis each time, they

are reflected. Other rays called Skew rays travel down the fibre without passing through the axis.

The path of a skew ray is typically helical wrapping around and around the central axis.

Fortunately skew rays are ignored in most fibre optics analysis.

The specific characteristics of light propagation through a fibre depends on many factors,

including

The size of the fibre.

The composition of the fibre.

The light injected into the fibre.

1.6 FIBRE TYPES

The refractive Index profile describes the relation between the indices of the core and

cladding. Two main relationship exists :

(I) Step Index

(II) Graded Index

The step index fibre has a core with uniform index throughout. The profile shows a sharp

step at the junction of the core and cladding. In contrast, the graded index has a non-uniform core.

The Index is highest at the center and gradually decreases until it matches with that of the cladding.

There is no sharp break in indices between the core and the cladding.

By this classification there are three types of fibres :

(I) Multimode Step Index fibre (Step Index fibre)

(II) Multimode graded Index fibre (Graded Index fibre)

(III) Single- Mode Step Index fibre (Single Mode Fibre)

1.7 OFC SPLICING

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Splices

Splices are permanent connection between two fibres. The splicing involves cutting of the

edges of the two fibres to be spliced.

Splicing Methods

The following three types are widely used :

1. Adhesive bonding or Glue splicing.

2. Mechanical splicing.

3. Fusion splicing.

1.8 FIBRE SPLICING

Operation of Fusion Splicers

Splicer Operation

It is awkward at first to hold, strip, cleave and place the fiber in the clamps. Practice makes

perfect. Here are five general steps to complete a fusion splice:

Strip, Clean, & Cleave

a. Strip

Strip fiber to appropriate length per your splicer's instruction manual

b. Cleaning

Clean the fiber with Fiber-Clean towelettes or a lint-free wipe and isopropyl alcohol so

that the fiber squeaks

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c. Cleaving

Place fiber (after stripping and cleaning it) in cleaver using the fiber guide to position.

It align the fiber in the cleave area to cleave at the proper length Depress the cleaver arm

gently . Remove and safely discard the fiber scrap

2. Load Splicer

Position tip of fiber near electrodes . Do not bump tips into anything . Ease placement by

bowing fibers in groove

3. Splice Fibers

READ The Manual.Place first cleaved fiber in v-groove with fiber tip near the electrodes

Close the fiber clamps Repeat on opposite side for second fiber.Select program on fusion

splicer . Initiate fuse cycle (can be manual or automatic)

4.Remove and Protect Splice

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Remove completed splice from splice area .Use Heat-Shrink oven (or mechanical

protection) to protect the splice Place splice tray in adjustable tray holder and insert protected

splice into splice

2 INTRODUCTION TO TRANSMISSION SYSTEM

A long distance or local telephone conversation between two persons could be

provided by using a pair of open wire lines or underground cable as early as early as mid of 19th

century. However, due to fast industrial development and an increased telephone

awareness, demand for trunk and local traffic went on increasing at a rapid rate. To cater to the

increased demand of traffic between two stations or between two subscribers at the same

station we resorted to the use of an increased number of pairs on either the open wire alignment,

or in underground cable. This could solve the problem for some time only as there is a limit to the

number of open wire pairs that can be installed on one alignment due to headway

consideration and maintenance problems.

It, therefore, became imperative to think of new technical innovations which could

exploit the available bandwidth of transmission media such as open wire lines or underground

cables to provide more number of circuits on one pair. The technique used to provide a number of

circuits using a single transmission link is called Multiplexing.

2.1 MULTIPLEXING TECHNIQUES

There are basically two types of multiplexing techniques

i. Frequency Division Multiplexing (FDM)

ii Time Division Multiplexing (TDM)

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Frequency Division Multiplexing Techniques (FDM)

The FDM techniques is the process of translating individual speech circuits (300-

3400 Hz) into pre-assigned frequency slots within the bandwidth of the transmission medium. The

frequency translation is done by amplitude modulation of the audio frequency with an appropriate

carrier frequency. At the output of the modulator a filter network is connected to select either a

lower or an upper side band. Since the intelligence is carried in either side band, single side band

suppressed carrier mode of AM is used. This results in substantial saving of bandwidth mid also

permits the use of low power amplifiers.

Time Division Multiplexing(TDM)

Time division multiplexing involves nothing more than sharing

a transmission medium by a number of circuits in time domain by establishing a sequence of time

slots during which individual channels (circuits) can be transmitted. Thus the entire bandwidth is

periodically available to each channel. Normally all time slots1 are equal in length. Each channel

is assigned a time slot with a specific common repetition period called a frame interval.

2.2 BASIC REQUIREMENTS FOR PCM SYSTEM

To develop a PCM signal from several analogue signals, the following processing steps are

required

• Filtering

• Sampling

• Quantisation

• Encoding

• Line Coding

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2.3 OVERVIEW OF SDH

With the introduction of PCM techonology in the 1960s, communications networks were

gradually converted to digital technology over the next few years. To cope with the demand for

ever higher bit rates, a multiplex hierarchy called the plesiochronous digital hierarchy (PDH)

evolved. The bit rates start with the basic multiplex rate of 2 Mbit/s with further stages of 8, 34 and

140 Mbit/s. In North America and Japan, the primary rate is 1.5 Mbit/s. Hierarchy stages of 6 and

44 Mbit/s developed from this. Because of these very different developments, gateways between

one network and another were very difficult and expensive to realize. PCM allows multiple use of

a single line by means of digital time-domain multiplexing. The analog telephone signal is sampled

at a bandwidth of 3.1 kHz, quantized and encoded and then transmitted at a bit rate of 64kbit/s. The

growing demand for more bandwidth meant that more stages of multiplexing were needed

throughout the world. Slight differences in timing signals mean that justification or stuffing is

necessary when forming the multiplexed signals. Inserting or dropping an individual 64 kbit/s

channel to or from a higher digital hierarchy requires a considerable amount of complex

multiplexer equipment.

Figure2.1. Plesiochronous Digital Hierarchies (PDH)

Traditionally, digital transmission systems and hierarchies have been based on multiplexing

signals which are plesiochronous (running at almost the same speed). Also, various parts of the

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world use different hierarchies which lead to problems of international interworking; for example,

between those countries using 1.544 Mbit/s systems (U.S.A. and Japan) and those using the 2.048

Mbit/s systems. To recover a 64 kbit/s channel from a 140 Mbit/s PDH signal, it’s necessary to

demultiplex the signal all the way down to the 2 Mbit/s level before the location of the 64 kbit/s

channel can be identified. PDH requires “steps” (140-34, 34-8, 8-2 demultiplex; 2-8, 8-34, 34-140

multiplex) to drop out or add an individual speech or data channel (see Figure 1).

2.3.1 The main problems of PDH systems are:

Homogeneity of equipment

Problem of Channel segregation

The problem cross connection of channels

Inability to identify individual channels in a higher-order bit stream.

Insufficient capacity for network management;

Most PDH network management is proprietary.

There’s no standardized definition of PDH bit rates greater than 140 Mbit/s.

There are different hierarchies in use around the world. Specialized interface

equipment is required to interwork the two hierarchies.

In 1988 SDH standard introduced with three major goals:

– Avoid the problems of PDH

– Achieve higher bit rates (Gbit/s)

– Better means for Operation, Administration, and Maintenance (OA&M)

SDH is an ITU-T standard for a high capacity telecom network. SDH is a synchronous digital

transport system, aim to provide a simple, economical and flexible telecom infrastructure. The

basis of Synchronous Digital Hierarchy (SDH) is synchronous multiplexing - data from multiple

tributary sources is byte interleaved.

2.3.2 SDH Advantages to Network Providers

High transmission rates: Transmission rates of up to 40 Gbit/s can be achieved in modern

SDH systems.

Simplified add & drop function: Compared with the older PDH system, it is much easier

to extract and insert low-bit rate channels from or into the high-speed bit streams in SDH.

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High availability and capacity matching: With SDH, network providers can react quickly

and easily to the requirements of their customers.

Reliability: Modern SDH networks include various automatic back-up and repair

mechanisms to cope with system faults

Future-proof platform for new services: Right now, SDH is the ideal platform for

services ranging from POTS, ISDN and mobile radio through to data communications (LAN,

WAN, etc.), and it is able to handle the very latest services.

Interconnection: SDH makes it much easier to set up gateways between different network

providers and to SONET systems. The SDH interfaces are globally standardized, making it

possible to combine network elements from different manufacturers into a network. The result is a

reduction in equipment costs as compared with PDH.

2.3.3 SDH Rates

SDH is a transport hierarchy based on multiples of 155.52Mbit/s

The basic unit of SDH is STM-1:

STM-1 = 155.52 Mbit/s

STM-4 = 622.08 Mbit/s

STM-16 = 2588.32 Mbit/s

STM-64 = 9953.28 Mbit/s

Each rate is an exact multiple of the lower rate therefore the hierarchy is synchronous

2.3.4 SDH Hierarchy:

SDH defines a multiplexing hierarchy that allows all existing PDH rates to be transported

synchronously.

The following diagram shows these multiplexing paths:.

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FIGURE 2.2 SDH HIERARCHY

Multiplex unit: A basic SDH multiplex unit includes multiple containers (C-n), virtual

containers (VC-n), tributary units (TU-n), tributary unit groups (TUG-n), administrative units

(AUn) and administrative unit groups (AUG-n), where n is the hierarchical sequence number of

unit level.

Container: Information structure unit that carries service signals at different rates. G.709

defines the criteria for five standard containers: C-11, C-12, C-2, C-3 and C-4.

Virtual container (VC): Information structure unit supporting channel layer connection of

SDH. It terminates an SDH channel. VC is divided into lower-order and higher-order VCs. VC-4

and VC-3 in AU-3 are higher-order virtual containers.

Tributary unit (TU) and tributary unit group (TUG): TU is the information structure

that provides adaptation between higher-order and lower-order channel layers. TUG is a set of one

or more TUs whose location is fixed in higher-order VC payload.

Administrative unit (AU) and administrative unit group (AUG): AU is the information

structure that provides adaptation between higher-order channel layer and multiplex section layer.

AUG is a set of one or more AUs whose locations are fixed in the payload of STM-N.

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2.3.5 The STM-1 Frame Format

The standardized SDH transmission frames, called Synchronous Transport Modules of Nth

hierarchical level (STM-N).

A frame with a bit rate of 155.52 Mbit/s is defined in ITU-T Recommendation

G.707. This frame is called the synchronous transport module (STM). Since the frame is

the first level of the synchronous digital hierarchy, it is known as STM-1. Figure 2 shows the

format of this frame. It is made up from a byte matrix of 9 rows and 270 columns. Transmission is

row by row, starting with the byte in the upper left corner and ending with the byte in the lower

right corner. The frame repetition rate is 125 ms., each byte in the payload represents a 64 kbit/s

channel. The STM-1 frame is capable of transporting any PDH tributary signal.

The first 9 bytes in each of the 9 rows are called the overhead. G.707 makes a distinction

between the regenerator section overhead (RSOH) and the multiplex section overhead (MSOH).

The reason for this is to be able to couple the functions of certain overhead bytes to the network

architecture. The table below describes the individual functions of the bytes.

Figure 2.3 STM-1 frame format

2.3.6 Section overheads:

RSOH (regenerator section overhead): The Regenerator Section OverHead uses the first

three rows & nine columns in the STM-1 frame

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Figure 2.4 Section overheads

A1, A2 The Frame Alignment Word is used to recognize the beginning of an STM-N frame

J0: Path Trace. It is used to give a path through an SDH Network a "Name". This message

(Name) enables the receiver to check the continuity of its connection with the desired transmitter

B1: Bit Error Monitoring. The B1 Byte contains the result of the parity check of the

previous STM frame, before scrambling of the actual STM frame. This check is carried out with a

Bit Interleaved Parity check.

E1 Engineering Orderwire (EOW). It can be used to transmit speech signals beyond a

Regenerator Section for operating and maintenance purposes

F1 User Channel. It is used to transmit data and speech for service and maintenance

D1 to D3 Data Communication Channel at 192 kbit/s (DCCR). This channel is used to

transmit management information via the STM-1 frames

MSOH (multiplex section overhead)

Figure 2.5Multiplex section overhead

The Multiplex Section OverHead uses the 5th through 9th rows, and first 9 columns in the

STM-1 frame.

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B2 : Bit Error Monitoring. The B2 Bytes contains the result of the parity check of the

previous STM frame, except the RSOH, before scrambling of the actual STM frame. This check is

carried out with a Bit Interleaved Parity check (BIP24)

K1, K2 Automatic Protection Switching (APS). In case of a failure, the STM frames can

be routed new with the help of the K1, K2 Bytes through the SDH Network. Assigned to the

multiplexing section protection (MSP) protocol

K2 (Bit6,7,8) MS_RDI: Multiplex Section Remote Defect Indication (former MS_FERF:

Multiplex Section Far End Receive Failure)

D4 to D12 Data Communication Channel at 576 kbit/s (DCCM). (See also D1-D3 in RSOH

above)

S1 (Bit 5 - 8) Synchronization quality level:

E2 Engineering Orderwire (EOW). Same function as E1 in RSOH

M1 Multiplex Section Remote Error Indicator, number of interleaved bits which have been

detected to be erroneous in the received B2 bytes.

Z1, Z2 Spare bytes

3 INSTALLATION AND COMISSIONING OF STM-1

(SIEMEN)

3.1 BLOCK DIAGRAM OF TRANSMISSION SYSTEM

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Figure 3.1Block Diagram Of Transmission System

DDF(Digital Distribution Frame): DDF (at transmitter side) receive PCMs from

exchange or station which are to be transmitted to another station or exchange. DDF have different

modules which connects PCM to STM-1 System. PCM connected to DDF from station through

copper cable and from DDF to STM-1 through PCM cable.

Transmitter: It is basically STM-1 system which helps to transmit PCMs through optical

fibre cable.STM-1 plays an important role in transmission system. STM-1 also helps in cross

connect the PCMs. This block contains MUX card and OLT cards.

E/O Converter: It is simply OLT card which converts electrical signal to optical signal

FDF(Fibre Distribution frame): This frame (at transmitter end) distribute fibre to different

station. FDF connect to system through patch card.

FDF(Fibre Distribution frame): This frame (at receiver end) collect fibre fom different

station. FDF connect to system through pigtails cable.

O/E Converter: This block converts optical signal to electrical signal.

Receiver: This block will collect all PCMs received at OLT card. It will connect all the

PCM to MUX card. Here they are connected to different station through DDF.

3.2 STM-1

The STM-1 is an optical STM-1/STM-4 add-drop multiplexer used to build STM-

1/STM-4 point-to-point links, STM-1 or STM-4 rings, or STM-1 line protection, so performing the

conveyance of 2 Mbit/s, 34 or 45 Mbit/s PDHlinks, of 155 Mbit/s STM-1 SDH links, of 10/100

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TransmitterE/O

ConverterO/E

Converter Receiver

Application area of Measuring InstrumentsIn Optical Fiber Communication system

Electrical

Signal

Optical

Signal

Electrical

SignalDDF

DDF

FDF

FDF

Mbit/s Ethernet links. STM-1 is product of AC-1 family.. STM-1 can be configured either as an

add/drop multiplexer or a terminal multiplexer depending upon the number of aggregate interfaces.

These interfaces can be either optical or electrical resulting in five different types of NEs It support

2Mbps data for transmit and receive on 1-PCM. STM-1 can transmit data upto 155.52Mbps.

In the AC1 family ADM (Add–drop multiplexer) and TM (Terminal Multiplexer)

along with the necessary cross connect functions are implemented in a single module. The same

unit also incorporates sufficient dropping capacity, which is upgradable, to make a cost effective

solution for small capacity networks. The system has protection facility and utilizes the inherent

management capacities of SDH with a ‘Craft Terminal’ (nothing but a PC) or through a full

fledged Network Management System. The physical and technical features of AC1 range of

equipments are briefly outlined here.

3.2.1 Key Features Of STM-1

Compact, modular design with single board ADM – 3 boards form a complete TM–1 or

ADM–1.

Extensive support of SDH management features.

Performance monitoring.

Synchronization management.

Fast protection switching

Sub–network connection protection (SNC–1)

Full VC–12 connectivity

Full ATM integration

NM2100 management.

Protection Function in the ADM

Cross Connection Function

3.3 STM-1 EQUIPMENT (SIEMEN)

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Figure3.2–Shelf view of STM-1 (Siemen)

3.4 MOTHERBOARD CARD

Figure3.3: Motherboard Card

Management and administrative ports:

COMM Interface: This isRS232 Port which is used to connecting system to computer

standard . This prt has Bit rate 19200 bauds (8 data bits, no parity and 1 stop bit).

ETH Interface: This interface is commonly called as Ethernet interface. It is used for

network management purpose (NMS). In practical session we have used this interface for

STM1configuration. This port can be operated at 10Mbps in either full duplex or half duplex

Synchronization port interface: In sync port we have provision of two external

synchronization inputs, these are T3_1 and T3_2 along with two clock outputs at 2MHz at pins

named as T4_1 and T4_2. All these input and output clock are compliant with ITU-T G.703

Recommendations.

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G.703 21×2Mbit/s traffic port:These ports on motherboard give us a provision for

termination and originating of 21 PCM on the mother board form the DDF (digital distribution

frame). Various features of these ports are given below:

Remote indication, remote control and station alarm port (LOOPS): This port is

basically used for the various alarm indication purpose. This facilitates us with four remote

indication inputs and two dry loops outputs for station alarm or remote control purpose.

2M Port: These are PCM ports carrying 2 Mbit/s data . These ports has 21 PCM carrying

capacity. These data port function block is composed of the following functions:

HPA : High order Path Adaptation (Tributary Unit order 12 management)

LPT : Lower order Path Termination (Virtual Container order 12 management)

PPI : PDH Physical Interface of G.703 port

Power supply access ports: "PWRA" and/or "PWRB" ports, used when the equipment is

powered from oneor two 48 Vsources, the power source(s) should be limited to 100 VA.

"PWR" port used when the equipment is powered from a main voltage (230 V AC), via an optional

power block (100-240V//48V - 1.5A).

3.5 IC1.1-2G CARD

Figure3.4-: IC1.1-2G Card

IC1.1-2G Card is OLT card . Two optical fibre cables are connected to this card. One cable

for transmit the sigal and another one is used for receiving the signal

EOW/AUX Configuration

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The EOW/AUX interface provides a 64 kbit/s data channel ; this channel may be carried by

a Byte of the SDH frame.

Select in the STM1-SOH configuration table :

E1 or E2 or F1

3.6 STM-DUAL

Figure3.5: STM-DUAL

Each STM-DUAL provides connection for:

One STM-1 SFP optical interface

One STM-1 electrical interface

One 64Kbps access “EOX/AUX” order wire or auxiliary channel

3.7 4E/FE

Figure 3.6:4E/FE CARD

Each 4E/FE provides connection for:

Traffic Ethernet interface either in 10Mbit//s or 100Mbit/s in full or half duplex mode.

3.8 E3DS3

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Figure 3.7:ES3DS3 CARD

Each E3DS3 provides connection for:

75Ω 34/45Mbps interface complaint with ITU-T G.703 and ETS 300 166 allowing 34/45

Mbps PDH streams.

3.9 21E120, 21E75 CARDS

Figure 3.8: 21E120 CARD

Each 21E120 provides connection for:

Trans and receive for 21 PCM on card each of 2Mbit.

3.10 COMMISSIONING OF STM-1(SIEMEN)

IP Addresses : To operate the STM -1 Equipment with NMS, we must set the IP address

of NMS. First three bytes of IP address of NMS must be same as that of STM-1 Equipment.

To change the IP address of NMS following point:

My Network Places---Properties---Local Area Network---Properties

IP Address ---Properties

Now change the IP addresses of NMS and STM-1 Equipment As shown..

IP address 135.10.110.7 is address of NMS and 135.10.110.11 IP address of STM-1

Equipment.One thing must be noted that first three bytes of IP address must be same. Subnet mask

remain same i.e 255.255.255.0

Now NMS can operate STM-1 Equipment.

Go to internet explorer.

Enter address of STM-1 Equipment (135.10.110.11)

Now we can operate the STM-1 equipment through NMS.

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3.10.1 EQUIPMENT

Figure3.10: Equipment Menu

3.10.2 Date and Time

Name:This menu item displays the "Equipment Name" dialog box.

Date and Time :When clicked, this menu item displays the "Date and Time" dialog box.

Apply button supplies the Equipment Date and Time with the PC Date and Time.

3.10.3 Inventories

Hardware Submenu Item

This menu displays the hardware inventory data, according to concerned modules.Software

Submenu Item

This menu displays the software inventory data, according to concerned modules.

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3.10.4 Security

Supervisor : All rights

Operator : May set configuration and maintenance operations

Observer : Not authorized to make any modifications (Read only access)

Passwords modification needs Supervisor access rights.

3.10.5 Management

This menu item displays the "Management" dialog box, which is the trap

destination table and the manager table. In network management, the manager sends to an

equipment some requests as SET and GET ; the equipment sends responses to the requests ; it can

also send TRAPS on its own if an event occurred in the equipment

3.10.6 Synchronisation

The role of synchronisation plan is to determine the distribution of

synchronisation in a network and to select the level of clocks and facilities to be used to time the

network. This involves the selection and location of master clocks for a network, the distribution of

primary and secondary timing through out the network and an analysis of the network to ensure

that acceptable performance levels are achieved

The hierarchical level of clocks are defined by ITU as follows :

PRC : Also called the primary reference clock or stratum-1 clock. Usually an

autonomous cesium clock or a rubidium clock locked to GPS. Accuracy: 10^-11

SSUT: Transit clock or stratum–2 clock. Accuracy: 10^-10

SSUL : Also, called local exchange clock or stratum–3 clock. . Accuracy: 10^-9

SES: It is a special clock which is not a stratum clock whose specifications are

specific to the requirements of an SDH equipment. . Accuracy: 10^-8

4 CONFIGURATION APPLICATION AND PERFORMANCE

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4.1 NETWORK TOPOLOGIES

Topology is the layout pattern of interconnections of the various elements (links,

nodes, etc.) of a computer network. Network topologies may be physical or logical. Physical

topology means the physical design of a network including the devices, location and cable

installation. Logical topology refers to how data is actually transferred in a network as opposed to

its physical design.

STM-1 can work with any topology given below:

Point to point topology.

Star topology.

Bus topology.

Ring topology.

But point to point and ring topology is commonly used in STM networks. Few of above

topologies are explained below.

4.1.1 Point to point topology

Figure4.1: Point to point topology

Point to point topology is used between the two systems in which both are connected to

each other. It is used at the edge of network.

4.1.2 Ring topology

Ring topology is used at the core of the communication network. In present days we are

using this topology in our core networks. Figure 4.2 shows ring of three systems.

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Figure4.2: Ring topology

4.2 AUTOMATIC PROTECTION SWITCHING (APS)

Two basic types of protection architecture are distinguished in APS. One is the

linear protection mechanism used for point-to-point connections. The other basic form is the so-

called ring protection mechanism which can take on many different forms. Both mechanisms use

spare circuits or components to provide the back-up path. Switching is controlled by the overhead

bytes K1 and K2.

4.2.1 Linear protection

The simplest form of back-up is the so-called 1 + 1 APS. Here, each working

line is protected by one protection line. If a defect occurs, the protection agent in the network

elements at both ends switches the circuit over to the protection line. The switchover is triggered

by a defect such as LOS. Switching at the far end is initiated by the return of an acknowledgment

in the backward channel. 1+1 architecture includes 100% redundancy, as there is a spare line for

each working line. Economic considerations have led to the preferential use of 1:N architecture,

particularly for long-distance paths. In this case, several working lines are protected by a single

back-up line. If switching is necessary, the two ends of the affected path are switched over to the

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back-up line. The 1+1 and 1:N protection mechanisms are standardized in ITU-T Recommendation

G.783. The reserve circuits can be used for lower-priority traffic, which is simply interrupted if the

circuit is needed to replace a failed working line.

Figure 4.3: Linear protection

4.2.2 Ring protection

A ring is the simplest and most cost-effective way of linking a number of network

elements. Various protection mechanisms are available for this type of network architecture, only

some of which have been standardized in ITU-T Recommendation G.841. A basic distinction must

be made between ring structures with unidirectional and bi-directional connections.

Unidirectional rings

Figure shows the basic principle of APS for unidirectional rings. Traffic is

transmitted simultaneously over both the working line and the protection line. If there is an

interruption, the receiver switches to the protection line and immediately takes up the connection.

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Figure 4.4 :Two fiber unidirectional path switched ring

Bi-directional rings

In this network structure, connections between network elements are bi-directional. This is

indicated in figure 8 by the absence of arrows when compared with figure 8. The overall capacity

of the network can be split up for several paths each with one bi-directional working line, while for

unidirectional rings, an entire virtual ring is required for each path.

)

Figure 4.5: Two fiber bi-directional line-switched ring (BLSR)

4.3 CROSS-CONNECTION

Cross Connection is important function of STM-1 Equipment. By using this function we

can connect PCMs of one station toPCMs of another station. For example 1 st PCM of Patiala

station can be connect to 7th PCM of Rajpura station.

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To perform these function we must following.

Shelf View---Cross-Connection---Select Output Port---Configure---Select Input

Port---Apply

Now connection are established.

We can also give the protection path, if working path has been failed.

Goto Configure---Protection---Protection Input Port---Apply

Another important function in cross connection is Multiple connections. By using this function we

can connect more than 1 PCM to another station’s PCM. For established multiple connections we

must following.

Cross-Connection--- Multiple Connection---Select OLT Card---Select N-PCM Output

Port---Select Starting Input Port---Apply

Now multiple connections are established. We can also give them protective pathby using

protection function of cross connection.

Each cross-connection is defined by its parameters:

Output port : Connection Destination End (Slot name and port number of selected card)

Mode : Unidirectional or Bi-directional

Input port : Connection Origin End (Slot name and port number)

VC-n type : Either VC4, VC3 or VC12

Protection : Protection Connection Origin End (Slot name and port number), if SNC

protection is used.

Status : Working or protection according to channel which is carrying traffic.

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Figure 4.6cross connection

On selected connection(s), following commands are available.

Configure:Allows to create or modify selected connection, namely configuration

parameters,SNC protection and operation mode

Delete :Allows to delete selected connection(s)

Before deleting connection, a confirmation request is displayed.

Deleting a bi-directional connection will delete all elementary connections composing it ; it

is not possible to delete only one elementary connection

Rename: Allows to modify connection(s) names (cf M1400)

See command Configure for more details

Multiple Connections:Allows to create several connection in one time

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5 ETHERNET ON S DH

Next Generation SDH enables operators to provide more data transport services while

increasing the efficiency of installed SDH/SONET base, by adding just the new edge nodes,

sometime known as Multi Service Provisioning Platforms (MSPP) / Multi Service Switching

Platforms (MSSP), can offer a Combination of data interfaces such as Ethernet, 8B/10B, MPLS

(Multi Protocol Label Switching) or RPR(Resilient Packet Ring), without removing those for

SDH/PDH. This means that it will not be necessary to install an overlap network or migrating all

the nodes or fiber optics. This reduces the cost per bit delivered, and will attract new customers

while keeping legacy services. In addition, in order to make data transport more efficient,

SDH/SONET has adopted a new set of protocols that are being installed on the MSPP/MSPP

nodes. These nodes can be interconnected with the old equipment that is still running.

5.1 VARIOUS FEATURES OF THE NEXT GENERATION S DH

GENERIC FRAMING PROCEDURE (GFP)

Generic Framing Procedure (GFP), an all-purpose protocol for encapsulating packet over

SONET (POS), ATM, and other Layer 2 traffic on to SONET/SDH networks. GFP is defined in

ITU-T G.7041 along with virtual concatenation and link capacity adjustment scheme (LCAS)

transforms legacy SDH networks to Next generation SDH networks.

There are actually two types of GFP mechanisms ;-

1. PDU-oriented known as Frame mapped GFP (GFP-F)

2. Block-code-oriented known as Transparent GFP (GFP-T)

1. GFP-F: -

GFP-F(Framed) is a layer 2 encapsulation in variable sized frames. Optimised for data

packet protocols such as DVD, PPP and Ethernet, MPLS etc Frame mode supports rate adaptation

and multiplexing at the packet/frame level for traffic engineering. This mode maps entire client

frame into one GFP frames of constant length but gaps are discarded. The frame is stored first in

buffer prior to encapsulation to determine its length. This introduces delay and latency.

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Figure 5.1Functional model of NG-SDH

2. GFP-T:

GFP-T is useful for delay sensitive services. GFP-T(Transparent) is a layer 1

encapsulation in constant sized frames. Optimized for traffic based on 8B/10B codification such

as VoIP, DVB-ASI, 1000BASE-T, SAN, Fibre Channel, and ESCON.

CONCATENATION (V-CAT & C-CAT):

SDH concatenation consists of linking more than one VCs to each other to obtain a rate

that does not form part of standard rates. Concatenation is used to transport pay loads that do not fit

efficiently into standard set of VCs.

Two concatenation schemes are:

Contiguous concatenation

Virtual concatenation

i. Contiguous concatenation:

The traditional method of concatenation is termed as contiguous. This means that adjacent

containers are combined and transported across the SDH network as one container. Contiguous

concatenation is a pointer based concatenation. It consists of linking N number of VCs to each

other in a logical manner within the higher order entity i.e. VC4 and above. The concatenated VCs

remain in phase at any point of network. The disadvantage is that it requires functionality at every

N/E adding cost and complexity. Lower order VCs (VC-12, VC3) concatenation is not possible in

contiguous concatenation .

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ii. Virtual Concatenation:

Virtual concatenation maps individual containers in to a virtually concatenated link. Any

number of containers can be grouped together, which provides better bandwidth granularity than

using a contiguous method. It combines a number of lower/higher order VCs (VC-12, VC3 & VC4

payload) that form a larger concatenation Group, and each VC is treated as a member. 10 Mb

Ethernet would be made up of five VC-12s, creating these finely tuned SDH pipes of variable

capacities improve both, scalability and data handling/controlling ability as per SLA (service level

agreement).

LINK CAPACITY ADJUSTMENT SCHEME (LCAS):

Link Capacity Adjustment Scheme (LCAS) is an emerging SONET/SDH standard and is

defined in ITU-T G.7042 having capability to dynamically change the amount of bandwidth used

in a virtually concatenated channel i.e. bandwidth management flexibility. LCAS is bi-directional

signaling protocol exchanged over the overhead bytes, between Network Elements that continually

monitors the link. LCAS can dynamically change VCAT path sizes, as well as automatically

recover from path failures. LCAS is the key to provide “bandwidth on demand”.

Benefits of LCAS:-

Call by call bandwidth (Bandwidth on demand)

Bandwidth on Schedule

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Block Diagram To Transmit data from One PC to Other PC Through Ethernet Card

Figure 5.4 Block Diagram To Transmit data from One PC to Other PC Through Ethernet Card

Testing:

1. Configured the TCP/IP of PC to 11 or 15.

2. Open the browser.

3. Put the global address in address bar and push GO.

4. To open second system in ring use it global IP address.

Results: Ring of system 13 and 15 is successfully accessed through Ethernet port.

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6 RESULT AND CONCLUSION

Although Hi-tech techniques like SDH making the world smaller these days, but these are

not going to fulfill the requirements of future generation. These techniques are lack of speed,

intelligence and efficiency which wouldn’t tolerable in the future. Future generation would require

more data rates and error less transmission which wouldn’t fulfill by present technologies. Future

every technology will be going to be IP based with introduction of IPv6 which offer us with huge

number of IP addresses so these present technologies has to either modified or completely

eliminated to make it compatible with IP based system demand. In case of wireless technologies

2G i.e. GSM support only 9.6Kbps which we very small which does not support essential VAS

related to data services. In switching, circuit switching is not going to support high switch rates and

high traffic rates in future.

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