This document provides information about Bharat Sanchar Nigam Limited (BSNL), the largest telecommunication company in India. It discusses BSNL's history, services offered, revenues, and recent agreements. It also describes the basic workings of a telecommunication network, including call setup between landlines and mobiles. Key components of the network like telephone exchanges, transmission systems, and technologies like GSM, CDMA, and optical fibers are explained at a high level.

1. INDUSTRIAL TRAINING
Telecommunication
SESSION : 2017-18
Presented By:-
RAJAT PUNDIR
BT 4060208
B.Tech (ECE)
4th Year

2.  Bharat Sanchar Nigam Limited was incorporated on 15th september 2000.
 Bharat Sanchar Nigam Limited is the world’s seventh largest telecommunication
company.
 Its responsibilities includes improvement of the quality of already installed telecom
services, expansion of telecom services in rural areas and acquiring confidence
among its customers.
 It provides a comprehensive range of services in India, which include wireless
connections, CDMA mobile, GSM lines, Internet, broadband, MPLS-VPN (multi
protocol label switching-virtual private network), VSAT (very small aperture
terminal) WIMAX, FTTHand VOIP (voice over Internet protocol).
 Within this short span of time, it has also become one of the largest public sector
companies in India.
 During the 2015-16 , turnover of BSNL is around Rs 32,919 crores.
 Recently, BSNL entered into aagreement with US-based networking solutions
coriant to chart the path to 5G and IOT in india.

3. WORKING OF BASIC TELECOMMUNICATION
NETWORK
This section includes brief introduction of how a call is processed when
we dial a call from basic telephone to another basic telephone or from
basic to mobile or vice versa.
CALL SETUP:
When a subscriber calls to another subscriber first its request goes to the
nearest switching centre that is PSTN (Public Switching
Telecommunication Network). Then it processes the caller and
subscriber’s number if it exists in the same BSC (Base Station
Controller) then call setup is completed.
If subscriber is not in the same BSC then call transfer to MSC (Mobile
Switching Centre) then it transfers the call to prior BSC then call setup
is completed.
If Caller calls to a mobile subscriber then call transfer is done by
MTSO(Mobile Telephone Switching Office)
now call transfer is done on BTS (Base Transceiver Station) and call
setup is completed.

4. Parts of a Telecommunication network
The main parts of a Telecommunication network are:
1.Telephone Exchange
2.Main Distribution Frame (MDF)
3.Switch Room

5. TELEPHONE EXCHANGE
Equipment which effects interconnection of telephones is known as switching
equipment.
The switching centre, 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 large enterprises. An exchange consists of electronic
components that interconnect (switch) telephone subscriber lines or virtual circuits of
digital systems to establish telephone calls between subscribers.

6. All telephone subscribers are served by automatic exchanges.
Today’s automatic exchanges use a pair of computers.
One running the program that provides services.
Second, monitoring the operation of the first, ready to take over in a few seconds in the
event of equipment failure.
Various exchanges present in BSNL are:
1. C-DOT ( centre for development of telematics)
2. OCB (organe de commande b2 version)
3. EWSD

7. C-DOT ( centre for development of telematics)
It was established in 1984 with initial mandate of designing and developing digital
exchanges it has offices in Delhi, Bangalore and Kolkata.
It provide solutions for current and future requirements of telecommunication and converged
networks including those required for rural application.
Provide market orientation to R & D activities and sustain C-DOT as center of excellence.
Some of the products of C-DOT are:
 MAX: main automatic exchange
Transmission equipment
Router
SGRAN (under development)
LTE-A(under development)
RAX: (rural automatic exchange is a small 256 lines switch for landlines that helped spread
telecom to rural parts of India)

8. MAIN DISTRIBUTION FRAME(MDF)
M.D.F. is a media between switching network and subscriber’s line. It
is a termination point within the local telephone exchange where
exchange equipment and terminations of local loops are connected by
jumper wires.
FUNCTIONS OF MDF:
All cable copper wires supplying services through user telephone lines
are terminated and distributed through MDF.
The most common kind of large MDF is a long steel rack accessible
from both sides. Each jumper is a twisted wire.
It consists of local connection and broadband connection frames for
the main Exchange area.
The MDF usually holds central office protective devices including heat
coils and functions as a test point between a line and the office.
It provides testing of calls.
It checks whether fault is indoor or external.
All lines terminate individually

9. Structure Of MDF

10. ORGANIZATION OF MDF
• Vertical side
• Horizontal side
Vertical side
Rack:- On the rack, the tags are situated. One rack is having eight tags. The counting is done
from up (0) to down (7).
Tags:- Each rack consists of eight tags
1 tag = 4 core
1 core = 4 bunch
1 bunch = 2 line
N.E:-The word NE stands for the ‘NUMBER OF EQUIPMENT’. It is used for testing number.
Wedge:- Wedge is used as a device for checking the ring. Wedge is placed in jack strips,
which is connected to telephone for checking.

11. Horizontal side
The horizontal side connected to the underground cable.
This cable is having 100 pairs.
These pair are distributed when company allot the telephone number to the
subscriber.
Horizontal side is again subdivided in two parts:
• One part is connected with the vertical side.
• Another with the subscriber line by using 100 pair underground cable.

12. POWER PLANT
 As we know that, the power is the main source or any organization. It is the case of E-10B
exchange. That is the first requirement of any organization is the input.
 The main source of this exchange is AC supply.
 The main part of power room are:-
1. Batteries for providing -48V supply
2. UPS (Uninterruptable Power Supply)
3. Charging - Discharging Unit
4. Inverter and Converter Unit

13. Switch Room
 Switch room consists of BM(Base module) and CM (centre module) cabinets mounted in
standard switch.
 These cabinets are fastened to a switch Room and interconnected by cables

14. VARIOUS INTERNET SERVICES
LEASED LINES
The information sent through the leased line travels along dedicated secure channels, eliminating
the congestion that occurs in shared networks.
between two points set up by a telecommunications carrier. They can be used for telephone, data,
or Internet services
A leased line (dedicated line) is a permanent Optical Fibre Cable(OFC) or telephone connection.
It is commonly used in ATMs.
WI-FI (WIRELESS FIDELITY)
A Wi-Fi network provides the features and benefits of traditional LAN technologies such as
Ethernet and Token Ring without the limitations of wires or cables.
WIFI is a wireless LAN Technology to deliver wireless broad band speeds up to 54 Mbps to
Laptops, PCs
Wi-Fi enabled phones etc.

15. GENERAL PACKET RADIO SERVICE (GPRS)
General packet radio service (GPRS) is a packet oriented mobile data service on the 2G and 3G
cellular communication system’s global system for mobile communications (GSM), In 2G
systems, GPRS provides data rates of 56-114 kbps.2g combined with GPRS is sometimes
described as 2.5G
GPRS extends the GSM circuit switched data capabilities and makes the following services
possible:
1. “ Always on” Internet access.
2.Multimedia messaging service (MMS).
3.Push to talk over cellular (PoC/PTT).
4.Point to Point (P2P) service: inter-networking with the internet (IP).
5.Increase message sending speed 30 messages per minute approximately.

16. BSNL Broadband Service
Broadband refers to a connection that has capacity to transmit large amount of data at high speed.
Presently a connection having download speeds of 256 kbps or more is classified as broadband.
When connected to the Internet broadband connection allows surfing or downloading much faster
than a dial-up or any other narrowband connections. BSNL offers 2 Mbps minimum download
speed for its Broadband connections.
Requirement for providing Broad Band connection
1.Personal Computer
2.ADSL Modem(asymmetrical digital system line)
3.Land Line Connection
4.Splitter for separating telephone from Personal computer
5.High speed Internet Access: This is the always-on Internet access service with speed ranging
from 256 kbps to 8 Mbps.

17. WIMAX
WI-MAX is an acronym that stands for World-wide Interoperability for Microwave Access and
this technology is designed to accommodate both fixed and mobile broadband applications.
SALIENT FEATURES OF WIMAX ARE:
1.OFDM-based physical layer.
2.Very high peak data rates.
3.Adaptive modulation and coding (AMC)
4.Support for TDD and FDD OFDMA.
5.Flexible and dynamic per user resource allocation.
6.Support for mobility.
7.IP-based architecture.
FTTH
FTTH is an acronym which stands for Fiber To The Home .In this technology an optical fiber of
high bandwidth and frequency is connected to the local residence of the user to provide high
speed internet facility upto higher mbps to gbps.This facility is first launched by BSNL in India.

18. FIBER OPTICS TRANSMISSION SYSTEM
FIBER OPTICS: The use and demand for optical fiber has grown tremendously and optical-
fiber applications are numerous. Telecommunication applications are widespread, ranging from
global networks to desktop computers. These involve the transmission of voice, data, or video
over distances of less than a meter to hundreds of kilometers, using one of a few standard fiber
designs in one of several cable designs.
ADVANTAGES OF FIBRE OPTICS :
Fiber Optics has the following advantages :
• SPEED: Fiber optic networks operate at high speeds - up into the gigabits
• BANDWIDTH: large carrying capacity
• DISTANCE: Signals can be transmitted further without needing to be "refreshed" or
strengthened.
• RESISTANCE: Greater resistance to electromagnetic noise such as radios, motors or other
nearby cables.

19. OPTICAL FIBER CABLE(OFC)
Optical Fiber is new medium, in which information (voice, Data or Video) is transmitted on the
principle of Total Internal Reflection through a glass or plastic fiber, in the form of light.
In the following sequence.
1.Information is encoded into Electrical Signals.
2.Electrical Signals are converted into light Signals.
3.Light Travels down the Fiber.
4.A Detector Changes the Light Signals into Electrical Signals.
5.Electrical Signals are decoded into Information.

20. In wireless communication every region is divided into cells. Cell size is constant for
whole system. GSM is a form of multiplexing, which divides the available
bandwidth among the different channels.
Most of the times the multiplexing used is either TDM (Time division multiplexing)
or FDM (Frequency Division Multiplexing).
SM differs from its predecessor technologies in that both signaling and speech
channels are digital, and thus GSM is considered a second generation (2G) mobile
phone system.
Global System For Mobile Communication

21. • 2G GSM networks operate in the 900 MHz or 1800 MHz bands
• GSM-900 uses 890–915 MHz to send information from the mobile station to the base
station (uplink)
•
•935–960 MHz for the other direction (downlink),
•
• providing 125 RF channels (channel numbers 0 to 124) spaced at 200 kHz. Duplex
spacing of 45 MHz is used.
GSM Frequencies

22. CODE DIVISION MULTIPLE ACCESS (CDMA)
ADVANTAGE Of CDMA:
Increased cellular communications security
Simultaneous conversations
Low power requirements and little cell-to-cell coordination needed by operators.
Extended reach-beneficial to rural users situated far from cells.

23. Network Structure

24. • MS refers to the physical phone itself
uniquely identified by the International
Mobile Equipment Identity (IMEI) number.
•SIM(Subscriber Identification Module) is
small smart card that is inserted into the
phone and carries information specific to
the subscriber identified by International
Mobile Subscriber Identity (IMSI) number.
Mobile Station

25. • It carry out radio communications between
the network and the MS.
• It has handles speech encoding, encryption,
multiplexing (TDMA), and responsible for
modulation and demodulation.
•Installed between 1 and 16 Transceivers
(TRX)
Base Transceiver Station (BTS)

26. • It is responsible for allocation of radio
channels.
•Operates frequency administration
• Power and signal measurements from the
Mobile station.
• Handovers from one BTS to another.
Base station controller

27. •It is responsible for call routing, call setup,
and basic switching functions.
•Different BSCs are connected to the MSC.
• Inner-BSC handoffs as well as coordinates
with other MSC's for inter-MSC handoffs.
MOBILE SWITCHING CENTER(MSC)

28.  HLR (Home Location Register)
maintains subscriber specific information
such as the MS,ISDN(Integrated
Services Digital Network), IMSI,
current location
of the MS, roaming restrictions.
 VLR (Visitor Location Register ) is a
database that contains a subset of the
information
located on the HLR.
DATABASES

29. REFERENCES