This document provides an overview of telecommunication systems used by Indian Railways. It includes block diagrams of the FOIS and Railnet connectivity in the Raipur division. The key network components like routers, switches, firewalls etc. are described. Methods of communication include optical fiber, microwave, radio and telephonic systems. The document also explains telecom technologies like DTMF signaling, cable route detection, telephone exchanges and UPS systems. Diagrams of network topologies, keypads and other systems are included for reference. Earthing systems are also summarized for electrical safety purposes.

1. A VACATIONAL TRANINIG
REPORT ON
TELECOMMUNICATION NI INDIAN
RIALWAYS RAIPUR
Submitted to
RAMKRISHNA RATHORE GOVERNMENT
POLYTECHNIC JANJGIR
GUIDED BY; SUBMITTED BY
Mr. SITARAM SHARMA OMPRAKASH SAHU
Mr. R.R. SAHU ET&T 3 Year 5sem

2. CONTENT
 INTRODUCTION
 BLOCK DIAGRAM
 NETWORK COMPONENT
 METHODS OF COMMUNICATION IN RAILWAY
 D.T.M.F(DUAL TONE MULTI FREQUENCY)
 TONES
 CABLE ROOT DETECTOR
 EXCHANGE
 UPS(UNINTERRUPTIBAL POWER SUPPLY)
 EARTHING
 CABLES

3. INTRODUCTION




Railway communication is means of sending or receiving information such as telephon
computer.
Basically telephone runs in two pairs but in railway
communication four pairs of telephone lines are used. Two pairs are used for transmis
are used for receiving.
Handset used in railway communication is known as omnivores circuit.

4. FOIS CONNECTIVITY DIAGRAM
,RAIPUR DIVISION
FIG(1.1) BLOCK DIAGRAM OF FOIS CONNECTIVITY,
RAIPUR DIVISION

5. RAILNET CONNECTIVITY DIAGRAM
OF
RAIPUR DIVISION
FIG(1.2): BLOCK DIAGRAM OF RAILNET
CONNECTIVITY OF RAIPUR DIVISION

6. NETWORK COMPONENT
ROUTER
SWITCH
FIREWALL
NETWORK INTERFACE CARD
MODEM
HUB
SERVER
FIG(1.3): ALL NETWORK COMPONENTS

7. ROUTER
• A router translates information from one network to another. It is similar to a
super intelligent bridge.
• A router can direct signal traffic efficiently.
• A router can route messages between any two protocol.
• Route messages between linear bus, star and star wired ring topologies.
• Route messages across fiber optics, coaxial and twisted pair cabling.
Fig(1.4);ROUTER

8. SWITCH
•The switch is used to incorrect the nodes.
•But it is more complex, versatile and also there is
no division of bandwidth among the nodes.
FIREWALL
It is security purpose software, which
is used to secure the server content, so the outside
user could not temper the information, the user can
read the information but can not write any thing.

9. NETWORK INTERFACE CARD
• It is a device having
intelligence to control access
to the network and enable
communication across the
network.
• Through network interface card
the nodes are connected
functionally and physically to
the network.
• It is also called network adapter. Fig (1.5). NIC CARD

10. MODEM



Modems are used for data transfer from
one computer network to another computer
network through telephone line.
The computer network works
in digital modes, while analog
technology is used for carrying
messages across phone lines.
Modulator converts information from digital
mode to analog mode at the transmitting end
And demodulator digital at
receiving end.

11. HUB
•It is active junction box, used to connect the
nodes and all the server using any type of cable.
•It contain division of network bandwidth.
•It can have a capacity of 8,16 or 24 nodes and the
maximum distance between hub and nodes is
100M.
SERVER
A shared machine together with the software
program which handles request
and distribute the network resources such
as data files and printer time both the machine
and its software are jointly referred the as the
server.

12. METHODS OF COMMUNICATION
IN
RAILWAY
OPTICAL FIBRE COMMUNICATION:-
• Between major stations.
• Multiple links possible in between.
• Fastest and secure.
• Largest bandwidth.
• Can carry very large number of channels.
MICROWAVE:-
• Wireless method.
• Prone to weather.
• Max range up to 40kms.
• Bandwidth of 300MHz-300GHz
RADIO COMMUNICATION:-
Between driver and station master
Low distance communication with in a railway station

13. LAN:-
• Wired communication between different computers at a stations.
• Internet and intranet access may be there.
• RJ-45 cable or coaxial cable is used.
• Works with in a station.
TELEPHONIC COMMUNICATION:-
• Works via a telephone line.
• Often single channel is used.
• Separate railway telecom. Exchange is set up for this purpose.

14. DUAL TONE MULTI FREQUENC
DTMF is a signaling system for identifying the keys or bettersay the number
dialed on a push button or DTMF keypad.
DTMF as the name suggestuses a combination of two sine wave tone to represent
a key.
These tones are called row and column frequencies as they
correspond to the layout of a telephone keypad.
It is a two digit dialing system.
Fig(1.6)-dual tone multifrequenc

15. DTMF KEYPAD

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A DTMF keypad generates a sinusoidal tone
which is mixture of the row and column
frequencies.
The row frequency are low group
frequency.
The column frequency are
high group frequency.
DTMF tones are able to represent one of the 16
different states or symbols on the keypad.
This is equivalent to 4 bits of data, also known
as nibble.
FIG(1.7): DTMF KEYPAD

16. TONES
DAIL TONES:-
 When handset is picked up from the cradle this tone
heard. If a free line is available this tone is
continuous burble sound of 400Hz modulated by
25Hz.
RING TONE:-
• This tone is a continuous burble
sound of 400 Hz modulated by 25Hz
BUSY TONE:-
• Called subscriber engaged with other call.
This tone is a continuous of 400 Hz,generally
on for 0.75 second & of for 0.75 second.
NUMBER UNOBTAINEDTONE:-
Dialed number connection no present in exchange. FIG(1.8): TONES

17. CABLE ROUTE DETECTOR


It is use for route tracing of any under ground metallic
cable in communication, power transmission,
distribution and signal cable networks or cable fault
location service provider.
It is also use to identification of wanted cable from
bunch of cable in communication network.
FEATURES:-
• Route tracing of under ground any metallic cable up
to 10km max length.
• Depth measurement up to 5M.
• Output power 1,2,4&8 watt selectable.
• Output frequency 480,1450,9820Hz
selectable. FIG(1.9): CABLE ROUTE DETECTOR

18. EXCHANGE
• Equipment which effects interconnect of telephones is
known as switching equipment.
The switching center, which houses the terminating and
switching equipment is called telephone exchange.
• A telephone exchange is a telecommunication system used in the public
switched telephone network or in largeente rprises.
FIG(1.10): EXHANGE/KRONE BOX

19. PRINCIPAL OF EXCHANGE
• Switching
• Signaling
• Controlling

20. CABLE
• Telecommunication cables area type of guided
transmission mediums.
• Cables are usually known to transmit electric energy (AC/DC).
• Cables in telecommunication field are used to transmit
electromagnetic waves, they are called electromagnetic wave guide.
Fig(1.11)

21. TYPES OF CABLES
• Paper Cable
• Derivation Cable
• Jelly Cable
• PBC Cable
• OFC Cable
• Submarine Cable
Now a days OFC,PBC, JELLY cables are mostly used
in telecommunication

22. UPS
(UNINTERRUPTIBLE POWER SUPPLY)
• Uninterruptible power supply is a device that provide battery backup when
the power fails or drop to an unacceptable voltage level.
• The switchover time must be small (2 to 4 ms) enough to not cause break in
the operation of the loads.
FIG(1.12): UPS

23. TYPES OF UPS
• ONLINE UPS
• OFFLINE UPS
• LINEINTERACTIVE UPS

24. ONLINE UPS
• Double conversion (AC to DC, DC to AC).
• IGBT PWM inverters .
• Continuous rated static bypass.
• Maintenance bypass.
• 6 or 12 pulse SCR Rectifier.
• Input harmonic filter.
FIG(1.13): ONLINE UPS

25. OFFLINE UPS
• Utility power is feeding the
load.
• Disconnect switch (solids state
or electro-mechanical).
• Charger is on, keeping the
battery under charge.
• Inverter is off.
• No voltage or frequency
regulation.
• 4 to 10 msec transfer time.
FIG(1.14): OFFLINE UPS

26. LINE-INTERACTIVE UPS
• Utility power is feeding the load, through energy storage device.
• Typical storage device motor generator.
• Disconnect switch.
• Charger is on, keeping the battery under charge.
• Inverter is off.
• Voltage regulation.
• 4 to 10 msec transfer time.
FIG(1.15):LINE-INTERACTINGUPS

27. EARTHING
The main reason for doing earthing for electrical safety.
When all metallic parts inelectrical equipment are
grounded then if the insulation inside the equipment fails there are no
dangerous voltage present in the equipment.
If the live wire touches the grounded case then the circuit is effectively
shorted and fuse will immediately blow.
When the fuse is blown then the
dangerous voltages are away.
Fig(1.16).- Earthin

28. PURPOSE OF EARTHING


Safety for human life/building/equipment.
Over voltage protection.
Voltage stabilization.