training report on my training experience in the telecommunication department in indian railways

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MAHARAJA SURAJMAL INSTITUTE OF
TECHNOLOGY
SUMMER TRAINING REPORT
On
SIGNAL ENGINEERING AND TELECOMMUNICATION
(IN ESTEEMED ORGANIGATION OF INDIAN RAILWAYS)
SITE OF TRAINING
SIGNAL AND TELE ENGINEERING DEPTT.,
NORTHERN RAILWAYS,
DIVISIONAL OFFICE- DELHI
TRAINING TAKEN FROM
(20.06.16 TO 31.07.16)
SUBMITTED BY
NAKUL SINGH ADHIKARI
ECE-1,3rd
YEAR (5th
SEM)
02115002814

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PREFACE
Engineering students gain theoretical knowledge only through books.
Only theoretical knowledge is not sufficient for absolute mastery in any
field. Theoretical knowledge in our books is not of much use without
knowing its practical implementation. It has been experienced that
theoretical knowledge is volatile in nature; however practical knowledge
imparts solid foundation in our mind.
I have covered in this report the history, latest developments in Railway
EC interface as well as related fields. I have studied the various uses of
EC in railways like PRS ,CONTROL ,UTS, OFC,EXCHANGE, RAILNET,
PAE SYSTEM .
.
This report is infecting a summary of, what I have learnt and seen
during my training in “Railway Organization, DELHI.” Succeeding
chapters give details what I have learnt in Divisional Railway
Manager (DRM) Office, DELHI .

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ACKNOWLEDGEMENT
The opportunity given to us by Indian Railways to learn and study about their signalling and
communication techniques over local area network and their state of the art devices and
telecommunication devices like modems, routers, batteries and their optical fiber network
splicing techniques will make a real difference in our engineering aptitude, knowledge and
abilities.
I would like to thank all those who helped me by giving their valuable thoughts and
information without which it would have been difficult for me to complete this project
report. I am obliged and honoured in expressing the deep sense of gratitude to my training
instructor Mr.Rajesh Yadav , S.S.E (TELE.) of DRM office ,Delhi for his helpful guidance and
suggestion at every stage of this report.
I express my gratefulness to Head, Department of Electronics and Communication, MSIT,
New Delhi for providing ample opportunities to pursue the present training work .
At last but not the least gratitude goes to all of my friends who directly or indirectly helped
me to complete this project report
Nakul Singh Adhikari

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TABLE OF CONTENTS
CHAPTER 1: INTRODUCTION 6
 About Indian railways
 Organisation overview
 Recent developments
CHAPTER 2 : TRAIN TRAFFIC CONTROL 9
 General
 DUAL TONE MULTI FREQUENCY CALLING SYSTEM
 Control interruptions
CHAPTER 3: RAILNET 17
 Tools
 Objectives
 How railnet works
CHAPTER 4: PUBLIC AMENITIES 22
 PRS
 NATIONAL TRAIN ENQUIRY SYSTEM
 Booking of ticket on internet
 UTS
 IVRS
CHAPTER 5: SOLID STATE LOCKING 27
 Railways signalling
 Operations of solid state locking
CHAPTER 6: Speeding the communication with Optical Fibers 30
CHAPTER 7: TELEPHONE EXCHANGE 33
BIBLIOGRAPHY 38

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CHAPTER 1
INTRODUCTION
1.1 About Indian Railways
Indian Railways, a historical legacy, are a vital force in our economy. The first railway on
Indian sub-continent ran from Bombay to Thane on 16th April 1853. Fourteen railway
carriages carried about 400 guests from Bombay to Thane covering a distance of 21 miles (34
Kilometers). Since then there has been no looking back. Today, it covers 6,909 stations over
a total route length of more than 63,028 kilometers. The track kilometers in broad gauge
(1676 mm) are 86, 526 kms, meter gauge (1000 mm) are 18, 529 kms and narrow gauge
(762/610 mm) are 3,651 kms. Of the total route of 63,028 kms, 16,001 kms are electrified.
The railways have 8000 locomotives, 50,000 coaching vehicles, 222,147 freight wagons,
6853 stations, 300 yards, 2300 goodsheds, 700 repair shops, and 1.54 million work force.
Indian Railways runs around 11,000 trains every day, of which 7,000 are passenger trains.
Presently, 9 pairs of Rajdhani and 13 pairs of Shatabdi Express Trains run on the rail tracks
of India.
It is interesting to note that though the railways were introduced to facilitate the commercial
interest of the British, it played an important role in unifying the country. Railways are
ideally suited for long distance travel and movement of bulk commodities. Regarded better
than road transport in terms of energy efficiency, land use, environment impact and safety it
is always in forefront during national emergency.
Indian railways, the largest rail network in Asia and the world's second largest under one
management are also credited with having a multi gauge and multi traction system. The
Indian Railways have been a great integrating force for more than 150 years. It has helped the
economic life of the country and helped in accelerating the development of industry and
agriculture. Indian Railways is known to be the largest railway network in Asia.
The Indian Railways network binds the social, cultural and economic fabric of the country
and covers the whole of country ranging from north to south and east to west removing the
distance barrier for its people. The railway network of India has brought together the whole
of country hence creating a feeling of unity among Indians.
1.2 Organization Overview
The Ministry of Railways under Government of India controls Indian Railways. The Ministry
is headed by Union Minister who is generally supported by a Minster of State. The Railway
Board consisting of six members and a chairman reports to this top hierarchy. The railway
zones are headed by their respective General Managers who in turn report to the Railway
Board.
For administrative convenience Indian Railways is primarily divided into 16 zones:

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1.2.1 The Ministry of Railways has following nine undertakings:
1. Rail India Technical & Economic Services Limited (RITES)
2. Indian Railway Construction (IRCON) International Limited
3. Indian Railway Finance Corporation Limited (IRFC)
4. Container Corporation of India Limited (CONCOR)
5. Konkan Railway Corporation Limited (KRCL)
6. Indian Railway Catering & Tourism Corporation Ltd (IRCTC)
7. Railtel Corporation of India Ltd. (Rail Tel)
8. Mumbai Rail Vikas Nigam Ltd. (MRVNL)
9. Rail Vikas Nigam Ltd. (RVNL)
Indian Railways have their research and development wing in the form of Research, Designs
and Standard Organization (RDSO). RDSO functions as the technical advisor and consultant
to the Ministry, Zonal Railways and Production Units.
1.3 RECENT DEVELOPMENTS
Now, to further improve upon its services, the Indian Railways have embarked upon various
schemes, which are immensely ambitious. The railway has changed from meter gauge to
broad gauge and the people have given it a warm welcome. Now, there are the impressive-
looking locomotives that haul the 21st-century harbingers-the Rajdhanis and Shatabdis-at
speeds of 145 kmph with all amenities and comfort. With these, the inconvenience of
changing to a different gauge en route to a destination will no longer be felt. The Research,

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Designing, and Standardizing Organization at Lucknow-the largest railway research
organization in the world-was constituted in 1957. It is constantly devising improvements in
the signaling systems, track design and layout, coach interiors for better riding comfort and
capacity, etc., along with improvements in locomotives. Improvements are being planned by
engineers. The workshops of the railways too have been given new equipment to create
sophisticated coaches at Perambur and Kapurthala and diesel engine parts at Patiala.
Locomotives are being made at Chittaranjan and Varanasi. This is in sharp contrast to the
earlier British conviction that only minor repairs wouldbe possible in India, so all spare parts
including nuts and bolts for locomotives would have to be imported from England. More
trains and routes are constantly being added to the railway network and services. The
British legacy lives on in our railway system, transformed but never forgotten. Long live the
Romance of the Rails! The network of lines has grown to about 62,000 kilometers. But, the
variety of Indian Railways is infinite. It still has the romantic toy trains on narrow gauge hill
sections, meter gauge beauties on other and broad gauge bonanzas as one visits places of
tourist interest courtesy Indian Railways! They are an acknowledgement of the Railways
that tourism as an industry has to be promoted and that India is full of unsurpassed beauty.
The Calcutta Metro is a fine example of highly complex engineering techniques being
adopted to lay an underground railway in the densely built-up areas of Calcutta city. It is a
treat to be seen. The Calcuttans keep it so clean and tidy that not a paper is thrown around!
It only proves the belief that a man grows worthy of his superior possessions. Calcutta is
also the only city where the Metro Railway started operating from September 27, 1995 over
a length of 16.45 km. There is also a Circular Railway from Dum Dum to Princep Ghats
covering 13.50 km to provide commuter trains.
In time of war and natural disasters, the railways play a major role. Whether it was the
earthquake of 1935 in Quetta (now in Pakistan) or more recently in Latur in Maharashtra, it
is the railways that muster their strength to carry the sick and wounded to hospitals in
nearby towns and to the people of the affected areas. In rehabilitation and reconstruction,
too, their role is vital. During the Japanese war, the Indian Railways added further laurels to
their record as they extended the railway line right up to Ledo in the extreme northeastern
part of Assam and thus enabled the Allied forces under General Stillwell to combat the
Japanese menace. In fact, several townships in Assam like Margherita and Digboi owe their
origin to the endeavors of the Indian Railways. It was the Assam Railway and Trading
Company that opened up the isolated regions of Assam with the laying of the railway lines
and thus providing the lifeline to carry coal, tea, and timber out of the area and bring other
necessary commodities to Assam and the adjoining countryside. Now, the Indian Railways
system is divided into 9 zonal railways, a metro railway, Calcutta, the production units,
construction organizations, and other railway establishments.

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CHAPTER :2
TRAIN TRAFFIC CONTROL
2.1 GENERAL
2.1.1 RAILWAY CONTROL CIRCUITS: Railway Control Circuits are omnibus telephone
circuits which provide communication with each train working point, thus facilitating
efficient train operation. They should provide satisfactory and reliable communication
between the controller and the various way-side stations, important signal cabins, loco
sheds, yard offices etc.
2.1.2. TYPE OF CONTROL SYSTEM: According to traffic requirements and to cater to
the needs of Electric Traction area, a section may be provided with one or more
Railway Control Circuits as detailed below :
a) SECTION CONTROL / TRAIN CONTROL : This is provided for
communication between the Section/Train Controller in the control office and wayside
stations, junction station, block cabins, loco sheds and yards in a division for the
control of train movements and effective utilisation of section capacity.
b) DEPUTY CONTROL : This is provided for communication between the
Deputy Controller in the control office and important stations, junctions & terminal
stations, yard master's offices, loco sheds and important signal cabins in a division for
supervisory control of traffic operation in general.
c) STOCK / ADM. CONTROL: This is provided for communication between the
Stock/Adm. Controller in the control office and yard master's offices at junctions and
Terminal stations in a division for getting information on the movements of rolling
Stock.
d) LOCO POWER CONTROL : This is provided for communication between the
Loco Power Controller in the control office and the various loco sheds, important
Stations and yards in a division for the optimum utilisation of the locomotives.
e) TRACTION LOCO CONTROL : Provided between traction loco controller
and loco sheds, important Station Master's Offices for optimum utilisation of electric
locomotives.
f) TRACTION POWER CONTROL : Provided between traction power
controller and SM's Office, FPs/SPs/SSPs for maintenance of OHE system.
g) S&T CONTROL : Provided between test room and way stations for
effective maintenance of S&T equipments.
h) EMERGENCY CONTROL: Provided from selected points along the track
route for establishing communication between train crew (in case of emergency),

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traction and permanent way staff with traction power controller. The emergency
sockets are provided on rail posts at an interval of 1 Km (Max.) along the route.
They are also provided at FP/SP/SSPs isolators in yards and near bridges.
i) EMERGENCY WIRELESS CONTROL COMMUNICATION: The following
equipments can also be utilized for emergency wireless communication where
such system exists:-
i) Handsets for Mobile Train Radio Communication (MTRC) in sections.
ii) Walkie-Talkie sets in sections where VHF communication from train to
control office has been provided in lieu of any physical medium or
MTRC.
Any other form of emergency wireless communication shall have the specific approval
of the Railway Board
2.1.3Train Control systems shall fulfill the following requirements :-
a) Rotary keys or push buttons of non locking type shall be provided for selective
calling of any station by the controller.
b) Facilities should be provided for selectively calling one or a group of stations
or all stations.
c) Means shall be provided to automatically inform the controller whenever the
bell/buzzer at the station rings in response to the call initiated by him.
d) The signalling used for selective calling shall not hamper normal telephone
conversation on the line.
e) Feature of prolonged ringing of any way-station shall be provided.
f) Adjustment and maintenance of the equipments in the control office and wayside
stations should be easy.
g) The equipment should be rugged and capable of intensive use.
h) The equipment should work satisfactorily within allowable margins of line
characteristics without frequent critical adjustments.
j) The system should be capable of progressive expansion without any
replacement.
k) The system should be compatible with overhead alignment and underground
cables as applicable.
l) Provision of intercommunication facility between several controllers in the
same control office may be incorporated in the control key board/panel wherever

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necessary.
m) Earth return circuits shall not be retained on AC traction and all Telecom
circuits shall work on metallic return.
n) Facility shall be provided in control office for transferring Emergency
Control(wherever exists) to Section Control circuit.
o) No overhead telecom alignment shall be within 50 meters from the AC
electrified track except when running strictly at right angles.
2.1.4 INTERCOMMUNICATION BETWEEN LOCAL TELEPHONE AND CONTROL
CIRCUIT
a) It is also desirable to make provision of an approved type to interconnect the
local telephone exchange with important control circuits to enable important officials
served by the local telephone exchange to gain access to such control circuits with or
without the assistance of an operator.
b) Such a provision shall not affect the performance of the control circuits from
the point of view of signalling or speech.
c) Whenever interconnection is made through an operator, the manual board shall
be provided with necessary supervisory facilities so that the telephone connected to
the exchange is disconnected from the control circuit as soon as the conversation is
over.
d) It should be ensured that only important officials have access to control circuits
in this manner.
2.1.5 TYPES: Traffic Control Equipments shall be of the following or any other
approved type.
(a) STC KEY SENDING SYSTEM: In this system the coded impulses are
generated by means of a rotary selector key (4001-A, 4002-A & 4002-B) mounted in a
key case being turned at a time to call any particular station. The impulses are
received at the way stations by polarized relays or selectors (4301-A) adjusted to close
the contact for the local ringing circuit for a particular code.
(b) PUSH BUTTON SENDING SYSTEM : The Push Button Sending System
consists of a push button panel and an impulsing unit in the control office. The panel
is equipped with 16 push buttons, and any particular station being called by operating
2 buttons corresponding to the first two digits of the code. For prolonged ringing, the
long ring key is operated. All stations can be signalled simultaneously by pressing a
general call key.
(c) DUAL TONE MULTIFREQUENCY SYSTEM: In this system two
frequencies are being transmitted simultaneously as per the standard DTMF

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Frequencies plan given in Annexure-II with 2 digit code to call either one station at a
time or a nominated group at a time or all at the same time.
The first two types are now obsolete and hence will not be described further.
Moreover as per policy of Board all overhead alignment system of BSNL as well as
Railways should be replaced in phased manner by 2008. However in extreme
circumstances where it is required the same should be followed as detailed in old
Telecom Manual (1971 edition).
2.1.6 INTERCOMMUNICATION EQUIPMENT: All controllers in a control office
shall be provided with an intercommunication system of approved type with facilities
for each controller to call any other controller, including Deputy Controller, Chief
Controller and the Telecommunication Maintainer/Inspector on duty.
2.1.7 JUNCTION EQUIPMENT: When control circuits originate in electrified section
and extend to a non-electrified section or vice versa 4 wire/2 wire OR 2 wire/4 wire
Speech Conversion and Junction equipment as per specification IRS: TC-46 shall be
provided at the junction.
2.2 DUAL TONE MULTI FREQUENCY CALLING
SYSTEM.
(a) This system for train traffic control equipment with voice frequency signaling
using Dual Tone Multi Frequency(DTMF) signals for 4 Wire and 2 Wire operation is
known as DTMF Calling System.
(b) The control office equipment is normally designed for 4 Wire operation which
can be converted into 2 Wire operation by provision of hybrid attachment. The way
station equipment shall be different for 4 Wire and 2 Wire working.
2.2.1 CONTROLLERS EQUIPMENT : The control office equipment consists of
operating console with DTMF code generator and voice communication equipment.

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(i) The operating console with code generator has following facilities :
a) Standard DTMF Key Pad for calling 99 stations with two push
button operation.
b) Station group code button A, B, C, D.
c) Push button for general call for calling stations simultaneously.
d) Push button LR for extending long ring at way stations.
e) Special push button 'RT' - for repeating last transmitted station
code.'RS' - to reset the system 'RC' - for row/column frequency check. 'DL' -
for cancellation of code.
(f) Visual indications for “System O.K”., “Display of station code” and
“power ON” indication.
(ii) The communication equipment consists of loudspeaker/microphone with
amplifiers and hand micro telephone and controllers headset.
a) For equipments with DTMF signalling proper functioning of the following
keys shall be checked.
i) Group codes A, B, C and D
ii) Long ring LR
iii) General call
iv) Special purpose keys
Reset - RS
Delete - DL
Repeat - RT
b) All visual indications provided on equipment shall be checked.
c) Monthly Maintenance: The following shall be checked:
i) Proper functioning of all station codes including special codes shall be
checked.
ii) Current Drain (max) on 12V DC side shall be as under:
Quiescent : 150 mA

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Working : 500 mA
iii) Current consumption of transmitter of Controller's head set and HMT
shall be between 100 and 150mA.
iv) DTMF signalling code level shall be between 0 dBm to - 7dBm across
a load of 600 ohms.
v) Row/column DTMF frequency shall be checked by pressing the 'RC'
button and shall be within the specified limits.
d) Quarterly Maintenance:
(i) Insulation resistance at room temperature of the office wiring when
measured with a 500V megger shall be more than 10 megohms between
conductor to conductor and more than 20 mega ohms between conductor and
Earth.
2.2.2 WAY STATION EQUIPMENT: The way station equipment shall consist of
DTMF decoder which can be assigned any DTMF station code/group code selectable
with DIP switches, voice communication equipment and 2-Wire/4-Wire desk type
control telephone.
WAY STATION EQUIPMENT
Weekly Maintenance: The following shall be covered :
i) Proper decoding of the set code of the equipment and actuation of
buzzer/ loudspeaker Ring back and LED on the control telephone.
ii) LED indication on telephone shall clear after hand set is lifted of the
cradle.
iii) Correct fitting of fuses and their rating.
iv) Cleaning and proper termination of wires on the terminals on the
rosette and CT box.
v) Telephone cord is in good condition and connected properly.
vi) Specific gravity of battery shall be 1210 and battery voltage shall be 12
volts - 10%, + 20%.
vii) Cleaning of battery terminals and vent plugs.

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2.3 CONTROL INTERRUPTIONS
2.3.1 PROCEDURE
a) As soon as interruption such as complete ringing failure, very low speech, hum,
noise or heavy induction on a control circuit for more than 10 minutes, the controller
on duty shall proceed to localise the shortest faulty section with the help of the way
station operating staff and other section controllers.
b) Technical staff in the control office and way-station may be called upon to assist
in the localisation whenever any technical difficulty arise.
c) As soon as the faulty section is localised, the matter should be brought to the
notice of the Telecommunication maintainer on duty, who will confirm the faulty
section.
d) This should be followed up by the issue of a 'XI' message by the controller,
addressed to the concerned lineman, EST, SDOT,DET or the P&T sub-division
concerned as also to the inspector incharge of the control office. Inspector incharge
of the section under which the interruption has taken place, and the ASTE/DSTE
giving details of time of interruption, name of circuit, interrupted section and the
nature of interruption/fault. Where the cable/overhead alignment is owned by the
railway, similar action shall be taken, intimation of faults in this case should be given
only to the concerned railway officials.
e) Besides a message, the lineman should also be ordered to patrol the interruption
section through a telephonic advice to the station master of the headquarters station of
the lineman.
f) Lineman at headquarters on either side of the interrupted section should be
advised as possible to enable patrolling from both directions.
g) In the event of any delay in the patrolling of the interrupted section for any reason,
the fact should be brought to the notice of the EST/SDOT/DET by the
Maintainer/Inspector incharge of the control office.
h) After confirming the faulty section, the maintainer should proceed to arrange for
substitution of the Deputy Control/Spare line to restore the interrupted circuit with the
assistance of the controller.
i) Restoration of the circuit after substitution can be taken as a confirmation that the
office equipments connected to the interrupted circuit are not defective.
j) If a substitution is not possible for any reason or the circuit is not restored even
after substitution, the section maintainer/inspector should be called upon to check the
office equipments in the interrupted section and promptly rectify the defects, if any.
k) On rectification of the fault, the controller shall issue XR/XT message to all
concerned giving details of the time of interruption, name of circuit, interrupted
section and the time of removal of fault.
l) In the event of the lineman reporting 'no fault found' after patrolling, in spite of the

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interruption persisting as observed by the controller of the telecommunication
maintainer in the control office, the interrupted section should be jointly tested by the
Telecommunication Inspector in charge of the said section with the concerned EST of
the P&T Department.
m) A similar joint test should also be undertaken in the case of repeated interruptions
in the same section.
CALCULATION OF APPROXIMATE LENGTH AND NUMBER OF STATIONS
ON A CONTROL CIRCUIT
Considering the restriction of 20 dB as the permissible loss on control circuits, the length of
the circuit for satisfactory speech can be estimated after allowing for the insertion loss of
telephone and the wiring at the stations.
In a hypothetical case where one station is talking tothe controller and two others listening
in, the permissible line loss will be 15.6 dB (allowingfor 3 dB insertion loss of telephone in
speaking condition and 0.2 dB while listening and 1 dBfor wiring at stations.
This loss is obtained on a 400 km circuit with 57 kg/km copper wire.
However, for determining the number of stations that can be connected in the circuit
signalling voltage is an important factor and from the graph attached it can be seen that for
400 km line (2200 ohm loop resistance) with 240 V Signalling voltage, about 60 selectors (or
telephones) can be connected and with 200 V, it can be 40 selectors.
Similar calculations can be made for other requirements of Signalling voltage.

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CHAPTER: 3 RAILNET
The Indian Railways is Asia's largest and the world's second largest rail network.
Adopting e-Governance in right earnest and to reap the benefit of IT explosion,
Indian Railways have established a
'Corporate Wide Information System'(CWIS) called RAILNET,
Abbreviated as RN henceforth. It provides smooth flow of information on demand for
administrative purposes, which would enable taking quicker and better decisions.
Realising the important role that information plays in customer services and in
railways operations, IR had embarked on its computerisation program. IR developed
dedicated skeletal communication network, as a basic requirement for train
operation
3.1 RAILNET comprises of -
 Intra-net
Intra-net is an internal network of Indian railway allowing the railway officers
and staff to communicate on this digitized network
 Inter-net
Internet allows user to get into a global communication method and global pool of
knowledge, advertisement and entertainment through www (World Wide Web) in a
secured manner.
3.2 TOOLS:-
 E-Mail
 EDI (Electronic Data Interchange)
 WWW
 FTP (File Transfer Protocol)
 TCP (Transmission Control Protocol)

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3.3 OBJECTIVES:-
Railnet is used to provide following services :
 Creation of Web pages.
 E-mail.
 Electronic transfer of data used for monitoring and
coordination purpose.
 Voice-over IP.
 Video-conferencing
 Web-based application software development
 Web surfing (Browser usage for internet and intranet).
3.4 HOW DOES RAILNET WORK?
Railnet is similar to internet. All the computers and communication cables that make up the
thousands of smaller networks at various railway offices are connected together to form the
railnet.It follows a simple rule, TCP/IP. Here packet switching, where a computer message is broken
into small packets , is used . Each packet consists of a destination address , a source address and
packet identity and user data. A packet can travel throughany path on the network .
 Different servers of railways are connected to each other via own microwave stations
to form a nationwide network of Indian Railways.
 Four wires are coming from microwave station and they are terminated on thelease line
modem. This modem is connected to router through a cable. Router isconnected to the
switch.
 Switch is an interface between server and router. Various hubs can be connected ina
cascade to increase the no. of terminations. This is a star topology.
 Hubs along with computers within the distance of 50 meter are terminated on theswitch. In
this manner all the computers in the LAN can share the data and canaccess the internet
through server.
 Router also provides the facility of Dial Up Networking . It can accommodate 8dial tone
modems which provide internet facility on distant computers.

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Railnet General Arrangement
RAILNET NETWORK COMPONENTS
A.SERVER
A network is a multiuser system because more than one person at a time can send requests
to a machine. A shared machine together with the software programs , which
handles requests and distributes the network resources such as data files and printer time
both the machine and its software are jointly referred as the server.
Server has following characteristics:
1) Hardware including motherboard of the server is entirely different from a normal P.C.
2) It can be used with two processors of 500MHz.
3)It contains 3 hard disks having capacity of 9GB.These are connected to the motherboard
through RAD controller card .
4) A server should be able to implement security for its data.5)It contains Microsoft Back
Office Server 4.01 software which comprises following programs:
a)Microsoft NT.
b)Microsoft BackOffice.
c)Site Management Server.
d)Proxy Software.
e)Service Network Administrator
f)Exchange Server.

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B.ROUTER
A router translates information from one network to another; it is similar to a super intelligent
bridge. Routers select the best path to route a message, based on the destination address and
origin. The router can direct traffic to prevent head-on collisions, and is smart enough to know when
to direct traffic along back roads and shortcuts. Routers know the addresses of computers, bridges,
and other routers on each side of the network. Routers can even "listen" to the entire network to
determine which sections are busiest; they can then redirect data around those sections until they
clear up. Routers can:
 Direct signal traffic efficiently.
 Route messages between any two protocols.
 Route messages between linear bus, star, and star-wired ring topologies.
 Route messages across fibre optics, coaxial, and twisted pair cabling.
C.SWITCH
The switch is used to interconnect the Nodes. But it is more complex and versatile,and also
there is no division of bandwidth among the nodes.
They are active device with following points :
(1)10Mbps, 100 Mbps, single-speed, or dual speed operation.
(2)Congestion control, which means that the switch should have enough buffers totake care of the
traffic peaks.
(3)Segmentation of local network
(4)Speed up the local network. They are of 8,16 or 48 ports active terminal.
D.FIREWALL
It is security purpose software, which is used to secure the server contents, so the outside user could
not temper the information. The user can read the information but cannot write anything.
E.HUB
It is active junction box, which is used to connect the nodes and all the servers using any type of
cable (UTP, Coaxial etc). It contains a division of network bandwidth.
The important parameters to be considered whole selecting are: -
 Support for dual-speed operations.
 Number and types of ports, UTP and BNC.
 Auto switching.
 Support a built-in segment switch.

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 Ease of configuration. It can have a capacity of 8, 16 or 24 nodes and the maximum distance
between Hub and nodes is 100 Mt. If distance is more, then additional HUB must be used
(but not more than 3).
Hub switch
Servers
-
Routers

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CHAPTER 4 : PUBLIC AMENITIES
4.1 PASSENGER RESERVATION SYSTEM (PRS)
 PRS started in 1985 as a pilot project in New Delhi. The objective was to provide
ticketing system for reserved accommodation on any train from any counter,
preparation of train charting and keeping a proper record of the money received.
This was implemented all over Indian Railway later on. With this implementation any
passenger can get a reserved ticket from one destination to another station of India
Railway from any Passenger Reservation Systems counter of Indian Railways.
 PRS networking of entire Indian Railways completed in April, 1999.
 PRS is running currently at 1,200 locations, Deploying 4,000 terminals, covering
journeys of 3,000 trains and executing ONE MILLION passenger transactions per day.
 Internet booking of tickets was started In August 2002.
 Internet booking timings extended to 4:00 a.m. – 11:30 p.m. from March 2005.
 This project involves the integration of five major regional reservation centers. It therefore
enables better coordination to improve the reservation process. The major regional centers
with all the information for their regions coordinate for better planning and control. This is a
complex but comprehensive system which provides for better functioning of the reservation

23. 23
process. IT enables this scale of coordination and such systems rely heavily on a strong IT
backbone. Leased lines are predominantly used to connect this system.
 This system demonstrates high levels of performance. It takes less than one second for a
local transaction and three seconds for a networked one. It is capable of providing
reservations for 22 hours per day.
EQUIPMENTS:
The equipment used in PRS are --
 Modem
 Multiplexing Equipment
 End terminal.
MODEM
Modem are used for communication various computer or between Computer &terminals
over ordinary or leased(dedicated ) telephone lines.We can use modems to log on to micro,
mini, main frame computer for line processing.We can use them to connect two remote
computers for data.
How does modem works ?
The word modem in feed is derived from the words modulate &demodulator.
Computer communicate in digital languages while telephone linescommunicate in analog
language. So an inter mediator required which cancommunicate both these language .
Modem transmits information between computer bit by one stream. Torepresent a bit (or
group of bits), modem modulates the characteristics of thewave that are carried by
telephone lines.
The rate at which the modem change these characteristics determines thetransmission
speed of data transmission .The rate of modem is called boundrate of modem.
The bound rate of modem is bits per second. In advance modulation such asquadrature
amplitude modulate 4 bits & transmitted it in each band. Thus thespeed of the modem
transmitting at 600 band would be 2400 bps.
The modems can transmit data in two formats: Asynchronous &Synchronous.
The analog modem switch at each location is connected to analog modemsof the main as
well as the stand by links.
If the main links fails, the switch units at either end switch the user equipment at the stand
by link. When the main links get restored, the analog modem switches the user equipment
back to main link.

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Multiplexing Equipment:-
There are two type multiplexing equipments for each channel.The multiplexer used may be
of 8-ports or 16-port .The data is get multiplexed at the rateof the 96KBps. The multiplexing
generally of analog type.
End Terminal:-
The end terminals of system is the station where the tickets to be Printed out .The terminal
consists of a computer system with a dot matrix printer. The number of the total end
terminal at the station can be increased or decreased according to the multiplexing used.

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4.2 National Train Enquiry Service (NTES)
National Train Enquiry System (NTES) is a centralized information system that provides up-
to-date and accurate information to passengers regarding arrival/ departure of passenger
trains including expected time of arrival (ETA) of trains.
4.2.1 Why NTES?
 Arrival and departure of passenger trains
 Platform berthing of passenger trains
 Facilities available at various stations ( e.g. retiring rooms)
 Railway Rules
 To make above information available on internet
The above information is made available to the public through:
 Display Boards
 Interactive Voice Response System ( telephone enquiry)
 Automatic Announcement System
 Face to Face Enquiry counters
 TV display
 Web Sites
4.3 BOOKING OF TICKETS ON INTERNET
E-ticketing initiative is critical in the current scenario of rapid growth of internet usage and
technologies. This offers customers the convenience of reserving tickets from the comfort of
their homes. This is in keeping with the times. The Indian railways are making an effort to use IT
for not only higher profitability but also for better customer facilities which will also indirectly
lead to higher profits. This is all made possible by IT.

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4.4 Unreserved Ticketing System (UTS)
 More than 1.2 crore Rail passengers travel in unreserved coaches and trains every
day and thus form the bulk of rail users. For this category of passengers Railways
have introduced the facility of Computerised Unreserved Ticketing System. It was
initially provided at 10 stations of Delhi area in the first stage as a pilot project on 15
August 2002. Another 13 stations of Delhi area were provided with UTS counters in
the second stage on 2nd Oct, 2002.
 UTS will provide the facility to purchase Unreserved Ticket 3 days in advance of the
date of journey. A passenger can buy a ticket for any destination from the UTS
counter for all such destinations which are served by that station. The cancellation of
tickets has also been simplified. Passengers can cancel their tickets one day in
advance of the journey
 from any station provided with a UTS counter. On the day of journey, the ticket can
be cancelled from station from which the journey was to commence.
4.5 Interactive Voice Response System (IVRS)
 Interactive Voice Response (IVR) is a software application that accepts a combination of
voice telephone input and touch-tone keypad selection and provides appropriate responses
in the form of voice, fax, callback, e-mail and perhaps other media. IVR is usually part of a
larger application that includes database access.
 An IVR application provides pre-recorded voice responses for appropriate situations, keypad
signal logic, and access to relevant data, and potentially the ability to record voice input for
later handling. Using computer telephony Integration (CTI), IVR applications can hand off a
call to a human being who can view data related to the caller at a display.
 Interactive Voice Response (IVR) systems allow callers to get access to information without
human intervention. Thus callers hear a pleasant and cheerful voice 24-hours a day, 7 days a
year without any attendant human fatigue. Since even the cost of the call is borne by the
caller, apart from the one-time installation cost, there is no running expense for the
company who deploys the IVR systems. Another advantage to the company is that it would
otherwise be impossible to handle high loads of callers, both in terms of time, and the cost
of the large number of individuals that it would require.
Interactive Voice Response Features
 Simple to use Graphical System Design Interface
 Multiple telephone line support both on Analog and Digital
 Advanced call screening and call switching options
 Can be integrated with any type of database. Playback data retrieved from database
 Text to Speech
 Call Transfer to other extensions, optionally announcing the Caller ID, allowing the recipient
to accept or decline the call
 Full logging of callers' details and all the selections made during the call
 Multi-Language support (English /Hindi)
 DNIS: (Dialled number identification service)
 ANI: (Automatic Number Identification)CHAPTER

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CHAPTER 5 : SOLID STATE INTERLOCKING
Solid State Interlocking is a data-driven signal control system designed for use throughout the
British railway system. SSI is a replacement for electromechanical interlocking which are based
on highly reliable relay technology---and has been designed with a view to modularity, improved
flexibility in serving the needs of a diversity of rail traffic, and greater economy. The hugely
complex relay circuitry found in many modern signalling installations is expensive to install,
difficult to modify, and requires extensive housing---but the same functionality can be achieved
with a relatively small number of interconnected solid state elements as long as they are
individually sufficiently reliable. SSI has been designed to be compatible with current signaling
practice and principles of interlocking design, and to maintain the operator's perception of the
behavior and appearance of the control system.
5.1 RAILWAY SIGNALING
Railway signaling engineers face a difficult distributed control problem. Train drivers can
know little of the overall topology of the network through which they pass, or of the
whereabouts of other trains in the network and their requirements. Safety is therefore invested
in the control system, or interlocking, and drivers are required only to obey signals and speed
limits. The task of the train dispatcher (signalman, or signal operator) is to adjust the setting
of switches and signals to permit or inhibit traffic flow, but the interlocking has to be
designed to protect the operator from inadvertently sending trains along conflicting routes.
The network can be operated with more security and efficiency if the operators have a broad
overview of the railway and the distribution of trains. Since the introduction of mechanical
interlocking in the late 1800's, and as the technology has graduallyimproved, the tendency has
therefore been for control to become progressively centralized with fewer signal control canters
individually responsible for larger portions of the network. In the last decade Solid State
Interlocking has introduced computer controlled signaling, but the task of designing a safe
interlocking remains essentially unchanged.
At the signal control centre a control panel displays the current distribution of trains in the
network, the current status of {signals}, and sometimes that of point switches (points) and other
signaling equipment. The railway layout is depicted schematically on the panel.
5.2 OPERATION OF SOLID STATE INTERLOCKING
There are seven (three aspect) main signals shown here, and three sets of points. It is British
Rail's practice to associate routes only with main signals. The operator can select a route by
pressing the button at the entrance signal (say, S7), then pressing the button at the exit signal the
consecutive main signal, being the entrance signal for the next route (S5). This sequence of
events is interpreted as a panel route request, and is forwarded to the controlling computer for
evaluation. Other panel requests arise from the points keys which are used to manually call (and
hold) the points to the specified position or from button pull events (to cancel a route by pulling
the entrance signal button).

28. 28
Figure: Signals (Si) on the control panel appear on the left to the direction of travel, each
signal
has a lamp indicator, and each main signal has a button. Switches (points, Pi) show the
normal
position, and there is usually a points key on the panel so one can throw the points
`manually'.
Lamps illuminate those track sections (Ti) over which routes are locked (white), and those in
which there are trains (red).

29. 29
When the controlling computer receives a panel route request it evaluates the availability
conditions specified for the route. These conditions are given in a database by Geographic
Data which the control program evaluates in its on-going dialogue with the network. If the
availability conditions are met the system responds by highlighting the track sections along
the selected route on the display (otherwise the request is simply discarded). At this point the
route is said to be locked: no conflicting route should be locked concurrently, and a property
of the interlocking we should certainly verify is that no conflicting route can be locked
concurrently.
Once a route is locked the interlocking will automatically set the route. Firstly, this involves
calling the points along the route into correct alignment. Secondly, the route must be proved--
-this includes checking that points are correctly aligned, that the filaments in the signal lamps
are drawing current, and that signals controlling conflicting routes are on (i.e., red). Finally,
the entrance signal can be switched off when the route is clear of other traffic---a driver
approaching the signal will see it change from red to some less restrictive aspect (green,
yellow, etc.), and an indicator on the control panel will be illuminated to notify the operators.
The operation of Solid State Interlocking is organized around the concept of a polling cycle.
During this period the controlling computer will exchange messages with each piece of
signaling equipment to which it is attached. An outgoing command telegram will drive the
track-side equipment to the desired state, and an incoming data telegram will report the
current state of the device. Signaling equipment is interfaced with the SSI communications
system through track-side functional modules. A point‘s module will report whether the
switch is detected normal or detected reverse depending on which, if either, of the electrical
contacts in the switch is closed. A signal module will report the status of the lamp proving
circuit in the signal: if no current is flowing through the lamp filaments the lamp proving
input in the data telegram will warn the signal operators about the faulty signal.
Other than conveying status information about points and signals, track-side functional
modules report the current positions of trains. These are inferred from track circuit inputs to
the modules. Track circuits are identified with track sections which are electrically insulated
from one another. If the low voltage applied across the rails can be detected, this indicates
there is no train in the section; a train entering the section will short the circuit causing the
voltage to drop and the track section will be recorded as occupied at the control centre. Track
circuits are simple, fail-safe devices, and one of the primary safety features of the railway. liv
All actions performed by Solid State Interlocking---whether in response to periodic inputs
from the track-side equipment, a periodic panel requests, or in preparing outgoing command
telegrams---are governed by rules given in the Geographic Data that configure each
Interlocking differently.

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Chapter 6: Speeding the communication with Optical
Fibers
Today's general demands to railway administrations all over the world are:

 more frequent departures and,

In order to meet above demands it is paramount to expand the existing transmission
capacity for tele-communication and to implement more flexible signal interlocking systems.
The telecommunication network has to operate with more subscribers as well as to carry a
number of new services, such as automatic train numbering, electronic reporting and
passenger information, freight control and voice channels to radio base stations for
mobileradio communication.
The old relay based signal interlocking systems for line block interlocking have to be
replaced by cheaper and more flexible fully electronic systems for the control of sig-nals,
points and other safety measures along the track. Communication Media:
The communication links making up the data network may be over a combination of any of
the following media :
 OFC,
 Digital MW,
 IP Radio links,
 VSAT, Analog MW,
 Twisted pair copper, for last mile connectivity.
35 Wherever feasible wireless LAN (WiFi, WiMax) as per latest international standards may
also be adopted.
 Railways Private Network is built up by utilising bandwidth from Railways’ own
Railtel Corporation of India (RCIL) or leasing bandwidth from BSNL or other service
providers.
 Network Speeds:
 The earlier networks were non-IP based and worked at speeds of 9.6 Kbps.
 Gradually some of the non-IP based network speeds were upgraded to 64 Kbps.
Generally higher speeds are not adopted in non-IP networks.
 Presently networks are mostly IP based and operate at speeds of 2 Mbps at the core
and distribution levels and 64 kbps at the access level.
 Speeds of n x 64 Kbps may be used at important access points depending on the
network traffic.
 Similarly at the core level n x 2 Mbps may also be adopted.
 In a centralized system as in FOIS, the core level comprises the communication links
between CRIS (Centre for Railway Information System)/ Rly.Board and zonal Hqrs.

31. 31
 Distribution level comprises the communication links between zonal Hqrs. and
divisions and access level is made up of links connecting the division to the activity
centres .
An 8 or 12 fiber cable is able to handle all to- day known railway transmission requirements
and even more. Furthermore, the transmission network is immune to electromagnetic
disturbances in connection with electric railway traffic. In optical fibre telecommunication
systems, primarily monomode fibers are used today, providing an extremely high
bandwidth (>300GHz x km) and a very low attenuation (0.2 dB/km).
We'll give a brief introduction to optical fibers here.
 An optical fiber is a thin, flexible, transparent fiber that acts as a waveguide, or “light
pipe”, to transmit light between the two ends of the fiber.
 Optical fibers are widely used in fiber-optic communications, which permits
transmission over longer distances and at higher (data rates) than other forms of
communication.
 Fibers are used instead of metal wires because signals travel along them with less
loss and are also immune to electromagnetic interference. Fibers are also used for
illumination, and are wrapped in bundles so they can be used to carry images, thus
allowing viewing in tight spaces. Specially designed fibers are used for a variety of
other applications, including sensors and fiber lasers.
The structure of a typical single-mode fiber .
1. Core: 8µm diameter
2. Cladding: 125µm dia.

32. 32
3. Buffer: 250µm dia.
4. Jacket: 400µm dia.
Optical Fiber Communication Network at Indian Railways
IR Vision is to tap revenue generation potential in the telecom and IT sector, using the
64,000-km long 'right of way' for laying optic fibres, signalling towers and other
infrastructure assets that Indian Railways owns.
OFCs are laid down along the track .
This will be done in collaboration between the RailTel Corporation and private sector
companies in a transparent framework. Use of OF Technology in IR
The advantages of using OFCs over conventional copper cables include:
i) free from EMI and RFI making it especially useful in electrified areas.
ii) supports low bit-error rate digital communication .
iii) very high traffic carrying capacity and hence potential for leasing excess capacity to
other users and providing other services.
38
iv) negligible cross-talk between channels.
v) insufficient commercial value of bits of cable and hence less prone to theft.
vi) multiple joints does not significantly degrade BER and therefore speech quality.
IR have commissioned their first optical fiber communication system, in the busy
suburban area of Mumbai over a distance of 60 km connecting 30 suburban stations during
1989. This was followed by installation of another 900 km fiber in connection with railway
electrification projects .
JOINTING AND TERMINATION OF OPTIC FIBRE CABLE
Techniques for jointing of optic fibre cable:
(a) Mechanical Splice This align the axis of the two fibres to be joined and physically hold
them together.
(b) Fusion Splicing This is done by applying localized heating (i.e. by electric arc or flame) at
the interface between the butted, pre-aligned fibre end, causing them to soften and fuse
together. Following steps are involved for jointing of the cable :-
 Preparation of cable for jointing
 Stripping/cutting the cable
 Preparation of cable and joint closure for splicing
 Stripping and cleaving of fibres
 Sealing of joint closure and
 Placing joint in pit

33. 33
Chapter 7 :Telephone exchange
A telephone operator manually connecting calls with cord pairs at a telephone switchboard.
In the field of telecommunications, a telephone exchange or telephone switch is a system of
electronic components that connects telephone calls. A central office is the physical building
used to house inside plant equipment including telephone switches, which make telephone
calls "work" in the sense of making connections and relaying the speech information.
ISDN
Integrated Services for Digital Network (ISDN) is a set of communication standards for
simultaneous digital transmission of voice, video, data, and other network services over the
traditional circuits of the public switched telephone network. It was first defined in 1988 in the
CCITT red book.[1] Prior to ISDN, the telephone system was viewed as a way to transport voice,
with some special services available for data. The key feature of ISDN is that it integrates speech
and data on the same lines, adding features that were not available in the classic telephone
system. There are several kinds of access interfaces to ISDN defined as Basic Rate Interface
(BRI), Primary Rate Interface (PRI), Narrowband ISDN (N-ISDN), and Broadband ISDN (B-
ISDN).
ISDN is a circuit-switched telephone network system, which also provides access to packet
switched networks, designed to allow digital transmission of voice and data over ordinary
telephone copper wires, resulting in potentially better voice quality than an analog phone can
provide. It offers circuit-switched connections (for either voice or data), and packet-switched
connections (for data), in increments of 64 kilobit/s. A major market application for ISDN in
some countries is Internet access, where ISDN typically provides a maximum of 128 kbit/s in
both upstream and downstream directions. Channel bonding can achieve a greater data rate;
typically the ISDN B-channels of three or four BRIs (six to eight 64 kbit/s channels) are bonded.
ISDN IN INDIA
Bharat Sanchar Nigam Limited, Reliance Communications and Bharti Airtel are the largest
communication service providers, and offer both ISDN BRI and PRI services across the country.
Reliance Communications and Bharti Airtel uses the DLC technology for providing these services.
With the introduction of broadband technology, the load on bandwidth is being absorbed by
ADSL. ISDN continues to be an important backup network for point-to-point leased line
customers such as banks, Eseva Centers, Life Insurance Corporation of India, and SBI ATMs.
TELEPHONE EXCHANGE RING TONES:
The status of a local telephone line (idle or busy) is indicated by on-hook or off-hook signals
as follows:

34. 34
On-Hook Minimum dc resistance between tip and ring conductors of 30,000 Ohms.
Off-Hook Maximum dc resistance between tip and ring conductors of 200 Ohms.
Telephone sets give an off-hook condition at all times from the answer or origination of a call
to its completion. The only exception to this is during dial pulsing of rotary or pulse dialing
phones.
Dial pulses consist of momentary opens in the loop; dial pulses should meet the following
standards:
Pulse rate: 10 pulses/second +/- 10%
Pulse shape: 58% to 64% break (open)
Inter-digital time: 600 milliseconds minimum
NOTE: Two pulses indicate the digit "2", three pulses indicate the digit "3", and so on up to
ten pulses indicating the digit "0".
Audible tones are used in the telephone system to indicate the progress or disposition of a
call. Precise dial tone consists of Current day "precise" tones consist of a summation of two
low distortion sine waves. Earlier tones included below consisted of a higher frequency
amplitude modulated by a lower frequency.
1. Dial tone (Real Audio) / Dial tone (WAV): Precise dial tone consists of 350 and 440 Hz
@ -13 dBm0 per tone, at telephone exchange (continuous). Earlier modulated dial tone
consisted of 600 Hz amplitude modulated by 120 Hz. For Touch-Tone compatibility reasons
this was replaced with precise dial tone on many electro-mechanical exchanges when they
were converted for Touch-Tone calling. lx
2. Busy tone: "Precise" busy signal (Real Audio) / "Precise" busy signal (WAV): 480
and 620 Hz @ -24 dBm0 per tone, at telephone exchange, interrupted at 60 interruptions
per minute (0.5 sec. on, 0.5 sec. off).
3. Reorder (Real Audio) / Reorder (WAV): (today's standard for "all trunks busy") 480
and 620 Hz interrupted at 120 interruptions per minute.
4. Ringback: "Precise" Ring-Back Tone (Real Audio) / "Precise" Ring-Back Tone (WAV):
440 and 480 Hz @ -19 dBm0 per tone, at telephone exchange (2 seconds on, 4 seconds off).
Compare this with 420/40 Hz Modulated Ring-Back Tone (Real Audio) / Modulated Ring-
Back
5. Call waiting (Real Audio) / Call waiting (WAV): 440 Hz @ -13 dBm0, at telephone
exchange (0.3 sec. on every 10 seconds)

35. 35
All Telephone Exchanges shall be
* Automatic
* Electronic
* Digital
* Stored Programme Controlled (SPC)
* Pulse Code Modulation (PCM, Time Division
Multiplexing (TDM) technology.
The exchanges shall be Transit cum Local Exchanges providing connectivity between
:
* Subscriber to Subscriber
* Subscriber to trunk
* Trunk to Subscriber
* Trunk to trunk
Separate trunk Automatic Exchange shall be provided at Zonal Railway Headquarter
for Indian Railways Network. The transit functions at other places shall be integrated
in the Local-cum-Transit Exchange
The exchange shall have ports to connect subscribers with
 Decadic phones
 DTMF phones
 Digital phones
 Hot line
 Long distance
 lead line through any media of communication
 Trunk through all media of communication
 (O/H, Cable, VHF, UHF, MW, OF)
 Attendant consoles
The Architecture of the Exchange shall be with the following protection arrangement.
a) Up to 128 ports
CPU and control cards -1 + 0 Configuration
Memory -1 + 0 Configurations
Power supply unit -1 + 1 hot Stand By (S/B)
b) Exchange with capacity higher than 128 ports
CPU and control card -1+1 hot Standby configuration & hot swappable
Memory -1+1 hot Standby configuration & hot swappable
Power supply card -1+1 hot Standby configuration & hot swappable
The exchange shall be fully non-blocking.

36. 36

37. 37
CONCLUSION
Indian Railways, as an organization is a very vast center of telecommunication in itself.
Today the telecommunicating world is getting its roots, grabbing the new era more firmly.
We think that our training was an success and we think that Indian Railways was an excellent
training institute for inquisitive emerging engineers.
In Indian Railways, training is given to engineering aspirant desiring to secure future in the
dynamic world of Telecommunication.
The main achievements of the training at Indian Railways are that we got familiar with the
latest technologies and principles of networking. The main achievement could be said to get
knowledge about recent technologies of LAN. We got experience as to how to organize the
things. After the completion of the training we consider ourselves capable of facing any other
challenge of that type. The training at Indian Railways cultivated the zeal of inquisitiveness
and the excitement to know more than more about this field in limited duration.

38. 38
BIBLOGRAPHY
1. Books –
 MTRC , form Indian Railway Institute of Signal and Telecom,
SECUNDRABAD.
 Signal And Telecom , from Indian Railway Institute of Signal and
Telecom, SECUNDRABAD.
 Signalling and Telecommunication in Indian Railways Report No. PA
26 of 200809 (Railways)
2. Website-
 www.iriset/ebooks/htm
 www.wikipedia.com
 www.Railnet.com
 www.indianrailway/organization/htm