Industrial Training Report- I-SLT

INDUSTRIAL TRAINING REPORT - I
TRAINING ORGANIZATION SRI LANKA TELECOM PLC
PERIOD OF TRAINING FROM: 11.11.2013 TO: 17.01.2014
FIELD OF SPECIALIZATION ELECTRICAL & ELECTRONIC
ENGINEERING
THUSHAN S.
E/10/361

i
Acknowledgements
I would like to take this opportunity to express my gratitude to all ladies and gentlemen who have
given their maximum involvement to conclude the Industrial Training Session at Sri Lanka Telecom
(SLT) successfully.
I was trained 02 sections in Sri Lanka Telecom and all the staff members contributed their maximum
to me throughout the training period. Especially sectional heads guided me to extract the maximum out
of each section. The Engineering Section of SLT is highly productive and mine of knowledge for
enhancing the skills and technical knowhow of any apprentice. I would like to express my sincere
gratitude to Mr. K. Kogularanjan, Manager (OPMC-Batticaloa) and his fellow staff for guiding me to
acquire the related engineering and real life applications of the theories which were thought during the
course. In addition I am very much pleased to acknowledge Mr. Y. Kishanthan, Engineer (Network-
Esatern Province), Added to that I would like to give my regards to all other engineers, technical
officers and other staff members for the support they have given to me throughout the session. Further,
it is a must to thank the Training Planning sections of SLT, for arrange my Training and necessary
instructions to carry out our chores during the whole training period.
Finally I would like to express my sincere gratitude to National Apprentice and Industrial Training
Authority (NAITA) for providing us the facilities to undergo a well standard training session, to
Industrial Training and Career Guidance Unit (ITCGU) of Faculty of Engineering as well as the Staff
of Department of Electrical and Electronic Engineering for guiding me throughout the training period.
Thank You,
S. Thushan,
Faculty of Engineering,
University of Peradeniya.

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CONTENTS
Acknowledgments i
Contents ii
List of Figures iv
List of Tables v
List of Abbreviations vi
Chapter 1 INTRODUCTION 1
1.1 Introduction of my training session 1
1.2 Introduction of SLT 2
Chapter 2 OPMC (Outside Plant Maintenance Centre)-Batticaloa 6
2.1 Introduction 6
2.2 General outside plant network and key components 6
Chapter 3 NEW CONNECTIONS AND MAINTENANCE 12
3.1 Cable Development and Maintenance 12
3.2 ADSL 15
3.3 New Connection and DATA 16
3.4 PSTN Maintenance 18
3.5 MDF Section 19
Chapter 4 CDMA 21
4.1 Introduction 21
4.2 CDMA Technology 21
4.3 CDMA Architecture 21
Chapter 5 PLANNING AND DEVELOPMENT 23
5.1 Job Profile of the Section 23
5.2 Introduction 23
5.3 Objective of Rehabilitation 23
Chapter 6 OPERATION SUPPORT 24
Chapter 7 SWITCHING 25
7.1 Introduction 25
7.2 SLT Switches 25
Chapter 8 TRANSMISSION 26
8.1 Introduction 26
8.3 Some Special Practical Experiences 27

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Chapter 9 POWER 29
9.1 Introduction 29
Chapter 10 CONCLUSIONS 30

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LIST OF FIGURES
Figure.1. 1 SLT Logo 2
Figure.1. 2 Organisation Chart of SLT 3
Figure.1.3 Optical Fibre Cable 5
Figure.2.1 Outside Plant Network 6
Figure.2.2 MDF 7
Figure.2.3 Man Hole 7
Figure.2.4 Cabinet 8
Figure.2.5 Pole Mounted MSAN and MSAN Ring 8
Figure.2.6 Distribution Point 9
Figure.2.7 Discharger 9
Figure.2.8 Rosette 10
Figure.2.9 Splitter 10
Figure.2.10 ADSL Router 10
Figure.2.11 Ethernet Cable 11
Figure.2.12 Telephone 11
Figure.3.1 25-Pair Cable 12
Figure.3.2 Process Followed For a Raychem Closure Installation 14
Figure.3.3 Bicotester 15
Figure.3.4 ADSL Architecture 15
Figure.3.5 ADSL Usage Detail Repot of a Customer 16
Figure.3.6 Damaged DATA Modem and Wiring due to Lightning 18
Figure.3.7 Damaged Fuses and Rosette Box 19
Figure.3.8 Fuse Used in MDF 20
Figure.3.9 Jumbering at MDF 20
Figure.4.1 CDMA Architecture 21
Figure.4.2 CDMA Fixed Wireless Phone 22
Figure.4.3 CDMA Fixed Wireless Terminal 22
Figure.7.1 ERICSSON AXE10 Switches 25
Figure.8.1 Transmission Network Layer in SL 26
Figure.8.2 Equip Used in Loop Testing 27
Figure.8.3 Clever, Stripper and Splicer 28
Figure.9.1 Batteries 29
Figure.9.2 DETROIT Diesel Generator 29

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LIST OF TABLES
Table 1.1 Training schedule 1
Table 3.1 Colour Codes 13

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LIST OF ABBERVIATIONS
ABBREVIATIONS DESCRIPTION
ADSL Asymmetric Digital Sub scribal Line
AE Assistant Engineer
CCT Cross Connection Terminal
CDM Cable Development and Maintenance
CDMA Code Division Multiple Access
CEO Chief Executive Officer
CRO Chief Regional Officer
DGM Deputy General Manager
DP Distribution Point
DSLAM Digital Subscriber Line Access Multiplexer
EP Eastern Province
FTTH Fiber To The Home
GM General Manager
HH Hand Hole
IDD International Direct Dialing
LTE Long Term Evolution
MDF Main Distribution Frame
MH Man Hole
MIMO Multi Input Multi Output
MSAN Multiple Service Access Note
NOC Network Operation Center
ODF Optical Distribution Frame
OPMC Outside Plant Maintenance Center
PSM Provincial Sales Manager
PSTN Public Switched telephone Network
RTO Regional Telecom Office
SAE Senior Assistant Engineer
SEAE Senior Executive Assistant Engineer
TDMA Time Division Multiple Access
VDSL Very high bit rate Digital Subscriber Line

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CHAPTER 01-INTRODUCTION
1.1 INTRODUCTION OF MY TRAINING SESSION
Under the course TR400-Industrial Training I was assigned as an apprentice at Sri Lanka Telecom
PLC, Batticaloa. for a period of 10 weeks, from 11/11/2013 to 17/01/2014 by the Industrial Training
and Career Guidance Unit (ITCGU) of the Faculty of Engineering, University of Peradeniya in
collaboration with National Apprentice and Industrial Training Authority (NAITA). The training
schedule which was given to me is mentioned in Table 1.1.
Table.1.1 Training Schedule
Worksite
Period
From To
OPMC-Batticaloa 11/11/2013 29/12/2013
Cable Development and Maintenance(CDM) 11/11/2013 17/11/2013
ADSL Maintenance section 18/11/2013 24/11/2013
Code Division Multiple Access(CDMA) 25/11/2013 01/12/2013
New Connection and Data 02/12/2013 08/12/2013
PSTN Maintenance 09/12/2013 15/12/2013
Planning and Development 16/12/2013 22/12/2013
MDF 23/12/2013 29/12/2013
NETWORKING- Batticaloa 30/12/2013 17/11/2014
Switching 30/12/2013 05/01/2014
Transmission 06/01/2014 12/01/2014
Power 13/01/2014 19/01/2014

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1.2 INTRODUCTION OF SLT
Sri Lanka Telecom PLC. (SLT) is one of Sri Lanka’s most valuable blue chip companies with a market
capitalization as at 31 December 2013 topping Rs.66 billion. Sri LankaTelecom is the national ICT
solutions provider and the leading broadband and backbone infrastructure services provider in the
country. The two main shareholders of Sri LankaTelecom as at year end were the Government of Sri
Lanka which held 49.5% through the Secretary to the Treasury and Global Telecommunication
Holdings N.V. of Netherlands, which owned a 44.98% stake. The balance shares are publicly traded.
Fig.1.1 SLT Logo
SLT- VISSION
All Sri Lankans seamlessly connected with world class information, communication and
entertainment services.
SLT- MISSION
Your trusted and proven partner for innovative and exciting communication experiences delivered
with passion, quality and commitment.
SLT- VALUES
Customer Caring - Put customers at the center of everything SLT do
Trustworthy - True to SLT promises
Innovative - Continuously invent new opportunities through creative thinking
Responsive - Ready to listen and act promptly
Teamwork - Act as one team with a common purpose to achieve common goals
Excellence - Committed to exceptional performance
Results Driven - Committed to enhancing shareholder value

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SLT- ORGANIZATION STRUCTURE
Fig.1.2 Organization Chart of SLT
Group of CEO
CRO
GM/Region 3
DGM/EP
Accountant
EP
Manager
RTO/Batticaloa
Manager
OPMC/Batticaloa
PSM
EP
Engineer
Network/EP
SEAE
Maintenance
SEAE
CDM & New
Connection
SEAE
Rehabilitation &
Development
SEAE
Switching,
Transmission & Power
SAE/PSTNSAE/ New
Connection & Data
SAE/CDM SAE/Power
& AC
AE AE
Transmission
AE
Switching
AE/MDFAE/CDMAAE/ADSL
Chairman and Board of Directors

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SLT-SUBSIDIARIES
 SLT Human Capital Solutions (Private) Limited
 SLT Property Management (Private) Limited
 SLT Publications (Private) Limited
 SLT VisionCom (Private) Limited
 Sri Lanka Telecom (Services) Limited
 SKY Network (Private) Limited
 Mobitel (Private) Limited
SLT-CUSTOMER PACKAGES
SLT provides various kinds of Packages to their customers. They introduce new technologies for the
satisfaction of their customers. More than this they provide 24 hours customer service for reduces the
inconvenience of telecommunication.
1. Megaline
 Single play, Double play and triple play offering for telephone, Broadband and PEO TV.
 Enabling the customer to choose the combination that is appropriate for envisaged usage.
 Value Added service also included.
2. Broadband
 Ten broadband packages available in the market to enable user to choose one that suits their
specific needs.
3. Peo TV
 Platform for best of local and international news and entertainment from around the world
 This offers new features such as digital quality pictures, time shifted TV, Rewind TV and
etc.
4. IDD
 All SLT residential phones are now IDD enabled and 232 numbers of countries connected
with direct links to provide better quality international service.

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SLT- FUTURE PALNS
 Introducing FTTH Networks.
FTTH has obvious advantages for the consumer, both today as well as in the foreseeable future,
offering improved performance for broadband services that are delivered primarily over copper
networks. FTTH provides the highest possible speeds of internet access downstream (from the
network to the end user) as well as upstream (from the user to the network) using Optical Fiber
Cables as shown in Fig.1.3.
Fig.1.3 Optical Fiber Cable
 Introducing MIMO, 4G LTE technologies with collaboration of Mobitel.
This is also for the faster internet access. With this 4G LTE technology can access internet in
mobile areas as well.
 Introducing VDSL technology
This VDSL2 is also for faster access of internet for the customer. But this project going to start
after finished the FTTH project.
 Microwave transmission links are replaced with of networks.

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CHAPTER 02-OPMC (Outside Plant Maintenance Center) – Batticaloa
2.1 INTRODUCTION
OPMC means outside plant maintenance center which is place where all new connections, maintenance
and rehabilitation are done. Under the manager of the OPMC there are several groups for various activities.
They are cable develop and maintenance (CDM), ADSL, New connection and Data, PSTN maintenance,
MDF, CDMA and Planning and Development. In OPMC centers have a system to store, update and get
information where ever they want. The specific system is called clarity.
2.2 GENERAL OUTSIDE PLANT NETWORK AND KEY COMPONENTS
Fig.2.1 Outside Plant Network
2.2.1 MDF
MDF is the main Flexible place as shown in Fig.2.1 which is used to Connect, disconnect or Check
errors of the communication. Meaning of MDF is main distribution frame. MDF has two sides. One
side is to connect exchange called primary side. Another one is called Secondary side which connected
to the customer side. Primary side and secondary side are connected by jumper wires. In MDF to
power up lines used -48V DC voltage which is supplied by exchange side. And According to the
connection type color codes of the jumper wires Varied

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 Data Connections -Red and White
 Voice Connections -Blue and white
 ADSL Connections-Black and White
Fig.2.2 MDF
2.2.2 Man Hole and Hand Hole
Man Hole and Hand Hole are the gates to the underground cables Maintenance and repairing. The
main difference between Hand Hole and Man Hole is a person can do repairs in a man hole. But hand
hole can operate only by using hands.
Fig.2.3 Man Hole

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2.2.3 Cross Connection Cabinet
Cabinet also a flexible points which connects MDF side and DP/CCT side through jumper wires. For a
particular DP there are 10 wires release from Cabinet. By using jumper cables, according to the
customer telephone number primary pair is connected to the DP side pair. Cabinet is used for a
protection and testing.
Fig.2.4 Cabinet
2.2.4 MSAN
Multiple Service Access Node (MSAN) is a new technology replaced for Cabinet. But here no need to
connect with MDF or Exchange. Because all the MSANs connected with Nation Ring in SriLanka.
The advantage of this new technology is however one side of the ring is disconnected MSAN works
with other side of the ring
Fig.2.5 Pole Mounted MSAN and MSAN Ring

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2.2.5 Distribution point / Cross Connection Terminal
Distribution point (DP) is the point where drop wire connected. And underground cable from Cabinet
and aerial cables are connected at DP. DP is mounted on poles and drop wires are drawn from DP’s to
customer’s home. Normally DP has maximum 10 wire loops.
Fig.2.6 Distribution Point
2.2.6 Discharger/ Fuse Box
Discharger is used to protect telephone, Router and subscribers from the high voltage current due the
lightning .If there is a high voltage current .the fuse will be burnt and the communication path is
disconnected. After that high voltage current pass to the earth through the wire.
Fig.2.7 Discharger

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2.2.7 Rosette
Rosette is used to connect Discharger and Telephone. Purpose of this instrument is easy to access and
change the connection pin.
Fig.2.8 Rosette
2.2.8 Splitter
Splitter is used when there is an ADSL line. Normally Data contains with high frequency range and
voice contains low frequencies. To filter them and connected to Telephone and router use Splitter. It
has a low pass filter. With is splitter we can access telephone and internet connection without
interruption.
Fig.2.9 Splitter
2.2.9 ADSL Router
ADSL Router is Provides internet service to customers through Ethernet interface.
Fig.2.10 ADSL Router

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2.2.10 Ethernet cable
Through Ethernet cable for ADSL routers to connect them with PCs, Ethernet switches, Wireless
access Points.
Fig.2.11 Ethernet cable
2.2.11 Telephone
Telephone is used for communicate with others. It consists of 4 circuits Receiving, Transmission,
Dialing, and Ringing circuits.
 Receiving circuit: - Convert electrical signal into audio signal.
 Transmission circuit: - Convert audio signal into electrical signal.
 Dialing circuit: - Voltages pulses generating when pressing numbers.
 Ringing circuit: - Ringing when call is coming.
Fig.2.12 Telephone

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CHAPTER 03- NEW CONNECTIONS AND MAINTENENCE
3.1 CABLE DEVELOP AND MAINTENANCE
3.1.1 JOB PROFILE OF THE SECTION
 Installing and maintenance of the primary side of the telephone lines (MDF to Cabinet)
 New Projects (MSAN)
3.1.2 INTRODUCTION
Cable Development and Maintenance section is responsible for the cable connect ion from the
primary side (MDF to Cabinet/ODF–Optical Distribution Frame to MSAN- Multi Service Access
Node) From the Line Side of the MDF, cables are drawn in sets of
1 0 / 2 0 / 3 0 / 5 0 / 200/300/600/../2400 pairs as underground cables through the duct lines
available/direct buried cables if the ducts are not available/aerial cables (for small number of pairs
only) to the Cabinets through HH (Hand Ho les) and Man Holes (MH).MH and HH are found in
different sizes to suit different capacities and they are used as a access interface to the
underground cables for installation/maintenance purposes. Since the copper pairs starting from
SLT end consist of large number of pairs, therefore color codes are used to indent iffy pair
numbers. More than this there are two other types of cables used for connection through direct sand
and water. They are Varry Cables and Submarine Cables.
Fig.3.1 25-Pair Cable

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Table.3.1 Color codes
1
White
Blue
2 Orange
3 Green
4 Brown
5 Slate
6
Red
Blue
7 Orange
8 Green
9 Brown
10 Slate
11
Black
Blue
12 Orange
13 Green
14 Brown
15 Slate
16
Yellow
Blue
17 Orange
18 Green
19 Brown
20 Slate
21
Violet
Blue
22 Orange
23 Green
24 Brown
25 Slate
3.1.3 TYPES OF FAULTS ON LINES
 Disconnection
This fault occurs due to a partial or permanent disconnection in the line. Because of this fault
there is no voltage (or current) to the phone. Therefore we couldn’t hear any sound in the
telephone.
 Earth
This fault occurs when A leg or B leg or both legs are connected to the earth.
 Short circuits
This fault occurs when A leg and B leg are short circuited. Because of this fault the physical
length of the circuit is short circuited.
 Current on line
This is an electrical contact between wires of one pair with a wire of another pair.

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3.1.4 SOME PRACTICAL EXPERIENCES
3.1.4.1 ISTALLATION OF A RAYCHEM CLOSURE
Task: Installation of a Raychem Closure to a cable joint made inside a man hole. The cable joint had
been made in order to avoidtheleakageofwaterduetotherainyseasons
Fig.3.2 Process Followed For a Raychem Closure Installation
3.1.4.2 CABLE FAULT LOCATING
Process Followed: All the lines of the joint were disconnected from their secondary sides and
each pair was checked using BICOTESTER for any fault in line, type of fault and the distance from
the joint to the fault location. After observing the fault location, it was concluded that there is a
discontinuity in the cable at that point due to the damages. After identifythe fault, it was corrected
by technicians in SLT.
Keep Propan-2-ol
With the cable

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Fig.3.3 Bicotester
3.2 ADSL
 Install ADSL/PEO TV newconnections.
 Attending ADSL/PEO TV fault reported.
3.2.2 INTRODUCTION
ADSL means asymmetric digital subscriber line. This is a high speed transmission technique used to
transmit both voice and data at the same time. More than one connection can be supplied using this
technique.
Fig.3.4 ADSL Architecture
3.2.3 ADSL/PEO TV FAULTS/PROBLEMS AND SOLUTIONS
 Component faults (component set up errors/ component failures)
 configuration errors(Router)

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 Fault in line (fault in line may occur due to inadequate speed required for ADSL/Peo Tv)
 Insufficient knowledge of the customer (Don’t know how to connect with splitter)
 Interruption of hackers to the customer accounts
Fig.3.5 ADSL Usage detail report of a customer
ADSL maintenance teams visit customer premises and check on the faults and fix them. And for
hacking problems report to head office for further actions. More than this there is automatic security
system also introduced by SLT for customer safety and satisfaction.
3.3 NEW CONNECTION AND DATA
Do initial wiring and configuration for PSTN and DATA connections. Normally provide PSTN
connection for normal customers and organizations as well. But provide DATA connection only for
mainly banks and others organizations. The responsible area of the section is from DP/CCT to
customer premises.
3.3.2 PROCESS FOLLOWED
In PSTN (Public Switched Telephone Network) in order to give any service, first the physical
connection is made from MDF (Main Distribution Frame) to the customer end equipment. For a voice
connect ion, the copper pair from customer end is connected to a subscriber card in switch via
MDF and the card port is configured and relevant details are updated in the system for the
connection. And for an ADSL/PeoTv connection, Copper pair is connected to the DSLAM port and
the corresponding port is configured according to the connection type by the ADSL NOC (Network
Operation Center) in Colombo for all the connection in SriLanka. In NGN, copper pair connection in made
between a port in nearest MSAN to the customer premises equipment and the port is configured and
system is updated with relevant data for voice/ADSL/PeoTVconnection.

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3.3.3 STANDARDS USING SLT WHILE IMPLIMENTING NEW CONNECTION
 Drop wire clearance
 Along the road- 4.5m, road crossing-5.0m
 Power lines
o Lower than 600V-0.6m
o 600V-7000V-1.2m
o 7000V-1500V-2m
 Drop wire connectors
 Lower than 500m-No joints
 Greater than 500m-One joint with drop wire connecter
 Construction of line and clearance from foliage not less than 1m
 Discharger fixed firmly at a reachable height wires without spirals
 Earth wire is to be connected to the discharger without spirals and joints
 Earth wire resistance should be less than 1000ohms
 Internal wire stapled at 0.4m intervals
 Rosette fixed on the wall 0.5m above the ground
 Buried depth of the pole 1/5 of the pole height
 Sag of drop wire
 0.4 m for less than 40cm of pole span
 0.7m for 40cm-50cm of pole span
 Exchange resistance- 2 Ohms
 MDF earth resistance< 5 Ohms
 Cabinet earth resistance< 30 Ohms
 DP earth resistance < 5 Ohms
 MDF to DP maximum allowable resistance for PSTN 1500 Ohms and for ADSL 600 Ohms
3.3.4 DATA FAULTS AND SOLUTIONS
Data connection is an important part for Banks, Financial Companies and some other online
administrative offices. Therefore SLT has a responsible for continuous communication for them. And
if the brake down period has reached the particular limit for the company SLT has to pay lack of
money as compensation. Therefore SLT and there officers be always alert for prevent the
disconnection. And most of the times many DATA systems damaged due to high voltage and high
current by lightning. Replacing the damaged instrument is the common solution method.

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Fig.3.6 Damaged DATA Modem and wiring due to lightning
3.4 PSTN MAINTENANCE
PSTN section is responsible for identify the faults through customer’s report and fix those problems
within 24 hours of reported time. More than this they do some maintenance works handovers from
CDM section as well. The working network of the PSTN maintenance is from DP/CCT to customer
premises. Working instruments of the section are DP, Fuse, Rosette box, Splitter and Telephone.
3.4.2 PSTN FAULTS, PROBLEMS AND SOLUTIONS
 Cable damage
 Short circuit connections
 Fuse damaged due to lightning
Modem
FuseEthernet Cable

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 Phone damaged
 Problem with Rosette code
 Carbon problem with Splitter and Rosette box (In Rainy seasons)
When customers reported about their problems to SLT, then workers of the PSTN maintenance section
visit customer premises and fix them. If they couldn’t get the solution for the problem with in their
network then handover the work orders to the CDM section. Most of the above problems occurred due
to the expired. Therefore replacing is a good solution for those problems.
Fig.3.7 Damaged Fuses and Rosette box
3.5 MDF SECTION
MDF provides connection between Exchange side and outside plant.
 Assign any telephone number to any loop. Because if there is any fault in the subscriber line,
MDF is the place used to assign new loop for same number. And customer can continue the
communication without any changes.
 Exchange cannot replace very easily. Because of that Protecting exchange side is one of the
main functions of the MDF. For those Arresters, Proper earth connection and other protection
used in MDF.
Damaged
Fuses
Damaged Rosette box
due to Carbon

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 Updating clarity. Because all the new connection and faults are informed to MDF, MDF must
update SLT data base.
 Isolation from Subscriber lines from exchange. To test conditions of the subscriber lines it is
must to isolate from exchange side.
 Also the test equipment is fixed at the MDF as it is a flexible point for testing. So the loop is
disconnected and connected to their testing equipment to check the condition of lines, such as
short circuit, cross connection, disconnection. That equipment is consisting of simple circuit
diagrams.
Fig.3.8 Fused Used in MDF
Fig.3.9 Jumbering at MDF

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CHAPTER 04-CDMA
4.1 INTRODUCTION
SLT provides many CDMA services such as voice, data, fax and payphones. SLT-CDMA (city link)
has an island wide coverage and it is a very popular and main telecommunication option especially
in the rural areas where there is no wired network or cellular mobile coverage. Some schools in
remote areas are connected to the School-Net using CDMA modems. And police offices in remote
areas using CDMA fax facility for their communication. Around 30,000 customers using CDMA
phones under the Batticaloa OPMC.
4.2 CDMA TECHNOLOGY
Cellular communication stated with AMPS (Advanced Mobile Phone System). Then it developed with
digital wireless communication. Called TDMA (Time Division Multiple Access). CDMA takes an
entirely different approach from TDMA. CDMA, after digitizing data, spreads it out over the entire
available bandwidth. Multiple calls are overlaid on each other on the channel, with each assigned a
unique sequence code. CDMA is a form of spread spectrum, which simply means that data is sent in
small pieces over a number of the discrete frequencies available for use at any time in the specified
range.
All of the users transmit in the same wide-band chunk of spectrum. Each user's signal is spread over
the entire bandwidth by a unique spreading code. At the receiver, that same unique code is used to
recover the signal. Because CDMA systems need to put an accurate time-stamp on each piece of a
signal, it references the GPS system for this information. Between eight and 10 separate calls can be
carried in the same channel space as one analog AMPS call.
4.3 CDMA ARCHITECTURE
Fig.4.1 CDMA Architecture

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MS (Mobile Station) - Originate and receive calls and communicate with the BTS.
BTS (Base Transceiver Station) - Transmits and receives radio signals.
BSC (Base Station Controller) - Functions of BSC are BTS control and management, call
connection and disconnection, Mobility Management, Power control, Radio resource management,
Provide stable and reliable radio link.
MSC (Mobile Switching Center) - Performs the switching functions of the system.
VLR (Visitor Location Register) - Database contains temporary information about subscribers
that is needed by the mobile services switching center (MSC) in order to service visiting
subscribers
HLR (Home Location Register) - Stores permanent data about subscribers.
SMC (Short Message Center) - Responsible for handling SMS
PDSN(Packet Data Serving Node)- Acts as a router and issues IP address
Fig.4.2 CDMA Fixed Wireless Phone
Fig.4.3 CDMA Fixed Wireless Terminal

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CHAPTER 05- PLANNING AND DEVELOPMENT
5.1 JOB PROFILE OF THE SECTION
 Plans for installation of MSAN, Cabinet and DP/CCT.
 Rearranging old copper connections and Rehabilitation.
 Co-ordinate SLT projects with private parties and manage them.
 Manage stocks of OPMC.
5.2 INTRODUCTION
Planning and Developing is the main of OPMC in SLT. Major projects of SLT depend on the report of
this division, for example when SLT install a new project, it should give profit to SLT. Therefore
achieving profit to the company and customer satisfaction this section comes into a main role of SLT.
5.3 OBJECTIVE OF REHABILITATION
 MDF – Repairing of faulty or damage tag blocks, Properly earthling, Removing unwanted
wires, Updating records, Checking arrestors /fuses & replacement, Drawing of jumper wires
properly, Labeling of cables, Marking of special circuits for easy identification (Data, ADSL
etc.)
 Overhead Routes - Recovery of unwanted items, Tensioning wires and cables, Installation of
stays and struts, Replacement of faulty lines, Normalization of O / H routes.
 Cabinets -Cleaning inside & outside, Removing unwanted jumpers, Updating records,
Labeling & earthling, Properly sealing.
 DP - Fixing properly to poles, Earthling, Replacing faulty DP, DP dressing & numbering,
Connecting through bridal rings, Fixing DP bands, Closing DP covers
 Route Clearance -
 Pole Recovery/Replacement - Recovering of excess, Unwanted or damaged poles,
Rearranging overhead route.
 Cable Recovery - Recovering of excess or faulty cables along routes.
 Internal Wiring - Fixing without joints, Fixing earth where necessary, Replacement of faulty
wires, Replacing earth wire joints, Checking earth resistance, Replacement of faulty
dischargers, Replacing of telephones which are more than 10 Years old.
 Pair Gain Recovery/Rehabilitation- Recovery / Rehabilitation of DSL, Fixing earth where
necessary, Normalization of overhead wires, Recovering of Exchange Unit
 MH/HH Repairs - Repairing of broken MH/HH, Labeling of cables, Raising or lowering of
MH/HH, Placing cables on brackets, Dewatering & Cleaning inside & outside , sealing duct
 Removal of Drop Wire / PVC Bunches- Extending cables, Splitting DPP, Opening of
stumps.

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CHAPTER 06-OPERATION SUPPORT
SLT is a one of the very huge organization with very wide coverage, a very large amount of staff
and with many services and products with complex and interconnected operations. In order to deliver
a good service to the customer, all these operations and all the sections and the staff must be
properly coordinated and properly guided at each and every moment. In order to satisfy the
above requirements there are several mechanisms have been built around the organization and its
operations.
One such mechanism is the ‘Clarity’ - the operation support system of the SLT. Clarity is an
internet based system which is a part of the SLT intranet .It provides an interface for each and every
sect ion to look up for the duties they are been assigned or to update the system when the
duties are finished/work progress so that other sections may work on that from that point. ‘Work
Orders’ is another concept which is a part of the clarity which defines the duties assigned to each
section on some task/service order. For a one task/service order to be completed, several sub tasks
may be needed to be done by relevant sections. Therefore work orders are issued with all the
requirements and due dates etc. for a single task and they are either displayed on Clarity or posted to
relevant sections. Another supporting mechanism is the concept of call centers. It makes much
flexible and efficient connection with the customers in order to feed the system with their feedback
or requirements. In order to elaborate, how these mechanisms take place, let’s consider several
examples. When a customer needs to complain regarding a service, by just dialing ‘1212’ it connects
the customer to any of the call centers and by considering the complain/request the call center officer
enter the data to the relevant section of the clarity which then will be directed to the relevant
section of the relevant branch through clarity as a work order so that they can attend to that.
When the relevant task is done, it could be entered to the system so that system will remove the
work order after saving necessary data on the task. I think this is a very efficient way which let the
customers more clear to the operation system, but in a very responsible manner. If we consider a
situation where the network planning sect ion needs to configure new links between two switches,
then several sections (transmission, switch) in both branches as well as branches in headquarters
must incorporate to finish the task. Then all the sections are issued with a work orders containing
detailed task descript ion for each section. If we consider another situation when a new PSTN
connect ion is made, the new connect ion section enters all the relevant details including
DP(Distribution Point) number, slot number, cabinet number etc. and the MDF staff feed the
system with the relevant block and tag block numbers and the switch enters the sub card numbers.
Slot numbers etc. for a given connection. In this way, all the sect ions involved are very well
connected and well informed about the tasks done by other sections which are relevant to them too

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CHAPTER 07- SWITCHING
7.1 INTODUCTION
In telecommunication switching is defined as the on demand establishment of individual connection
from a desired inlet to desired outlets for the required time enabling transfer of information.
Switching is required for SLT operations for two main reasons. One is for establishment of
customers to the network and the other is for the internal communication. We need switching since
we do not have unlimited resources so that everyone is connected to everyone else or every
network link has unlimited capacity. When we consider switching, SLT has two main networks.
One is the PSTN/Legacy network which uses Time Division Multiplexing and the other is
IP/MPLS network which uses packet switching.
7.2 SLT SWITCHES
In times Cross bar technology used for switching purposes. Then semi electronic switches were
introduced to SLT called “Teletypewriter”. Manufacture was “Kitache” (Version: C23SE) in 1978.
Then “American Telephone and Telegraphy” company introduced another fully electronic switch
(Version: SESS). It can only communicate for PSTN connections. In 1996 “Erission” company
introduced a switch (Version: AXE 10) which can communicate for PSTN and ADSL as well. Recently
MSAN was introduced by SLT for all kind of telecommunications such as PSTN, ADSL, DATA, etc.
MSAN is easiest and fastest way to communication. However SLT using the old AXE 10 switches as
well. Normally MSANs working with 230V supply and working with battery power as well. However
the charging capacities of those batteries are very low. Therefore it makes many problems in practice.
Fig.7.1 ERICSSON AXE 10 Switches

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NGN Network-Packet switched network
IP/MPLS NETWORK USING O/F
LINKS
CHAPTER 8 -TRANSMISSION
8.1 INTRODUCTION
SLT provides many services to the customers all around the island and we can say that for each
service, there should be one island wide network since all the services are about communication. For
almost all the services the service providing equipment are placed in SLT premises and customers
are connected to the network through access network. The network which connects each service
providing equipment to others and to the service network can be considered as the core network
and the above connectivity is provided by transmission section. The transmission links for
connecting local service nodes and the core network is managed by transmission section. Mainly
there are two core network types in SLT and different transmission networks as well
Legacy Network-circuit switched n/w
SDH/PDH TRANSMISSION N/W
USING RADIO OR O/F LINKS
Fig.8.1 Transmission Network types in SLT

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8.2 JOB PROFILE OF THE SECTION
 Maintenance of Radio and Fiber Networks
 Test and provide Transmission Links
 Keep and Upgrade relevant data
8.3 SOME SPECIAL PRACTICAL EXPERIENCES
8.3.1 TRANSFERING OF RADIO LINKS TO O/F NETWORK
Some Radio transmission links between Batticaloa TX room and Polanaruwa repeater station were
transferred to the Optical fiber links .First two O/F ports with minimum loss were selected from
free ports in ODF (from Batticaloa to Polanaruwa) by testing the receiving power of each link by
connecting a power meter from Polanaruwa end after sending an optical signals from an optical
source from Batticaloa end. Then the wiring was tested by sending a signal from SDH/PDH analyzer
and check for the receiving signal through SDH/PDH analyzer.
Optical Source Power Meter SDH/PDH Analyzer
Fig.8.2 Equipment used in loop testing
8.3.2 SPLICING
Optical fiber is the newest technology in SLT, when installing transmission lines there are chances
may occur for disconnection of optical fibers. Connection of optical fibers is not an easy method like
copper cables. Because for a perfect communication the optical fibers should be connect 100%
exactly.
8.3.2.1 Parts of an Optical cable
 Core
 Positioned at the center of the cable
 As thin as human hair
 Made of glass
 Light travels inside the core

28
 Cladding
 Positioned around the core
 Made of glass with low reflection
 Reflect light back in to the core
 Jacket
 Also called buffer coating
 Made of plastic
 Outer most covering
 Protect the fiber from damage and moisture
8.3.2.1 Optical fiber splicing procedure
 Stripping -Used stripper tool
 Cleaning -Used alcohol
 Cleaving -Used cleaver
 Splicing -Used Splicing tool
 Protection -Sleeve
Fig.8.3 Clever, Stripper and Splicer

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CHAPTER 9 –POWER
9.1 INTRODUCTION
Power is the main part of the telecommunication network. All the instruments used in SLT need
particular amount of power. When we consider about the usage of power are operation of Switches,
MSANs, CDMA instruments, cooling system etc. Therefore CEB provide a special and separate
connection to all Regional telecom offices. Therefore SLT have to maintenance of the power system
that CEB provide. And SLT have to maintenance their generator which are replacement of main
power and mobile generators as well for MSANs.
9.2 JOB PROFLE OF THE SECTION
 Supply main power system
 Installation and Maintenance of Generators
 Maintenance of Rectifier and Battery
 Maintenance Air conditioners
Fig.9.1 Batteries
Fig.9.2 DETROIT Diesel Generator

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CHAPTER 10- CONCLUSIONS
The industrial training program at SLT, the major telecommunication service provider for Sri Lanka
was a great experience for me where I could have industrial training experience in many
aspects of telecommunication. Other than that, it was a great experience for me where I could
learn and practice ethics and social skills for an industrial environment and as well as I could gain
the insight to appreciate even the smallest, but honest , supportive and cooperative contribution of
the staff towards the success of a company and for a better working environment.
Although I was assigned to OPMC-Batticaloa for 10 weeks, I got a chance to have my training in a
well-planned way in OPMC sect ions as well as in switching and transmission sect ions at that
period for which I am very thankful to Mr. K. Kogularanjan -the Manager at OPMC and
Mr.Y.Kishanthan- Engineer Network in Eastern Province. And I think it was better that I had the
lecture series at training center after I being exposed to the field in some level because there I
first tried to understand the technologies and the system by own withthe help of the staff and some
introductory lectures from the staff and then at the training centers I could confirm what I
learned. It was actually motivated me to learn things. I really appreciate all the staff members and
the lectures at SLT who helped me to gain all these experiences and the training Planning section of
SLT for coordinating my training.
I think it would be great if Trainees could have more experience on the network planning,
international switching, transmission and other engineering divisions so that they could be
more exposed to technologies and the challenges to be faced as engineers in the future.
Finally I would like to state that the training experience I had at SLT organized by the Industrial
Training Unit of University of Peradeniya in collaboration with NAITA was up to my
expectations and it was a great experience for me which would definitely help me in my future
carrier.

Industrial Training Report- I-SLT

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