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INDUSTRIAL TRAINING SEMINAR REPORT

ON

BHARAT SANCHAR NIGAM LIMITED

SESSION 2014-2015

Submitted for the partial fulfillment for the degree of

BACHELOR OF TECHNOLOGY AT

G.L.A. UNIVERSITY, MATHURA

Submitted To: Submitted By: Ms. Vani Gupta Pradeep Yadav Assistant Professor B.Tech.(IV) Year ECE Department Rollno.111300129

------------------------------------------------------------------------------ Department of Electronics & Communication Engineering

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Table Of Contents

S.No. Topic Page No. 1. Cover Page 1 2. Abstract 3 3.Working Of Basic Telecommunication Network 4

4.Function Of Exchange 5

5.Elecronic Exchange 5

6.Main Distribution Frame 6

7.POWER PLANT 7 8.COMPUTER UNIT 8

9.CENTRAL AIR CONDITIONER 8

10.VARIOUS INTERNET SERVICES 9

11.BSNL Broadband Services 9

12.WIMAX 10

13.FTTH 10

14.OSI Networking Model 10 15.Fiber Optics Transmission System 11 16.Optical Fiber Cable 12 17.Mobile Communication 13 18.GSM 16 19.GPRS 16 20.CDMA 16 21.Conclusion 17 22. References 18

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ABSTRACT

The initial phase of telecom reforms began in 1984 with the creation

of Center for Department of Telematics (C-DOT) for developing

indigenous technologies and private manufacturing of customer

premise equipment. Soon after, the Mahanagar Telephone Nigam

Limited (MTNL) and Videsh Sanchar Nigam Limited (VSNL) were

set up in 1986.The Telecom Commission was established in 1989. A

crucial aspect of the institutional reform of the Indian telecom sector

was setting up of an independent regulatory body in 1997 – the

Telecom Regulatory Authority of India (TRAI), to assure investors

that the sector would be regulated in a balanced and fair manner. In

2000, DoT corporatized its services wing and created Bharat Sanchar

Nigam Limited.

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.On the 28th January 1882, Major E. Baring, Member of the 's

Council declared open the Telephone Exchanges in Calcutta, Bombay

and Madras. The exchange in Calcutta named the "Central

Exchange", was opened at third floor of the building at 7, Council

House Street, with a total of 93 subscribers. Later that year, Bombay

also witnessed the opening of a telephone exchange.

Internet Service Providers (ISPs) have been allowed to set up

International Internet Gateways, both Satellite and Landing stations

for submarine optical fiber cables.

Two categories of infrastructure providers have been allowed to

provide end-to-end bandwidth and dark fiber, right of way, towers,

duct space etc.

Guidelines have been issued by the Government to open up Internet

telephony (IP).

BSNL is now providing various voice and internet facilties such as

3G,Broadband,WIMAX,FTTH etc.

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 then call setup is

completed.

If subscriber is not in the same BSC (Base Switching Centre) then call transfer to MSC

(Main 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 now call transfer

is done on BTSs (Base Transceiver Station) and call setup is completed.

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FIG :HOW LINE REACHES FROM SUBSCRIBER TO EXCHANGE

FUNCTION OF EXCHANGE:

Exchange of information with subscriber lines is done through exchange.

Various exchanges present in BSNL are:

E-10B

OCB283

EWSD

CDOT

All exchange has some purposes and some basic structural units, which are:

1. subscribers connection unit

2. switching network (CX)

3. control unit

4. OMC

ELECTRONICS EXCHANGE

It is based on the automatic control by stored programmed in computer linked to it. It

cover all the main drawbacks of above mentioned exchange. It may be digital or

analog but mostly digital electronics exchanges are now common. It base on the

principal time division switching or space division switching. Space division

switching is used for analog electronics exchange and time division switching is used

for digital exchange.

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Space Division switching System In a space Division Switching system, a continuous physical path is set up between

input and output terminations. This path is separate for each connection and is held

for the entire duration of the call.

Time Division Switching System In Time Division Switching, a number of calls share the same path on time division

sharing basis. The path is not separate for each connection, rather, is shared

sequentiallyThe repetition rate is 8 KHz, i.e. once every 125 microseconds for

transmittion.

MDF(MAIN DISTRIBUTION FRAME):

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.

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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.

ORGANISATION OF THE MDF

PARTS OF THE MDF

Horizontal side

Vertical side

HORIZONTAL SIDE:

It is again subdivided in to two parts

Exchange side

Line side

RACK: - On the rack, the tags are situated. One rack is having eight tags. The courting is

done from up (0) to down (7).

TAG: - Each rack consists of eight tags.

1 tag = 4 core

1 core = 4 bunch

1 bunch = 2 line

Vertical side is again subdivided in two parts:

One part is connected with the horizontal side and another with the subscriber line by using

100 pair underground cable.

VERTICAL SIDE:

The vertical aside connected to the underground cable. This cable is having 100 pairs.

These pair is distributed when we allot the telephone number to the subscriber.

POWER PLANT

It consists of a online U.P.S. (Uninterruptable Power Supply).

It provides -48V to the switch rooms and 48V to the connections.

Batteries are artificially discharged once in a year for their maintenance.

Cooling is provided through fans & AC.

There is earth region too for protection.

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COMPUTER UNIT

As the name specified it is the main part of the exchange that deals with the all services

provided by the exchange to the customers with the help of computer. It also provides the

updated data to all other part of the exchange.

IVRS is used for the change number services provided by the exchange.

CERS are provided by the exchange to avoid the problems that the users are facing the

repairing of telephone. In this system when the user enters it’s complained it gets directly

entered to the server and user is allotted with an id number.

CENTRAL AIR CONDITIONER

For the function of electrical equipment, cooling system is basic requirement. The basic

advantages of cooling systems are to cool the exchange and to maintain the thermal

stqability of the exchange.

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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 fiber optic or telephone connection.

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.

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

Personal Computer ADSL Modem Land Line Connection Splitter for separating telephone from Personal computer High speed Internet Access: This is the always-on Internet access service with

speed ranging from 256 kbps to 8 Mbps.

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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:

OFDM-based physical layer.

Very high peak data rates.

Adaptive modulation and coding (AMC)

Support for TDD and FDD OFDMA.

Flexible and dynamic per user resource allocation.

Support for mobility.

IP-based architecture.

FTTH

FTTH is an acronym which stands for Fiber To The Home.In this technology an optical

fiber of desired bandwidth and frequency is connected to the local residence of the user

to provide high speed internet facility upto gbps.This facility is first launched by BSNL

in India.

OSI NETWORKING MODEL: The open systems interconnection model

defines all the methods and protocols needed to connect one computer to any other over a

network.It consists of following seven layers:

Physical Layer:The physical layer defines the properties of the physical medium used to

make a network connection Data Link Layer: the data link layer, layer 2, defines standard that assign meaning to the bits carried by the physical layer Network Layer: The network layer, Layer-3, is where a lot of action goes on for most

networks. Transport Layer: The Transport Layer, layer-4, manages the flow of information from one

network node to another. Session layer: The session layer, layer-5, defines the connection from a user to a network

server, or from a peer on a network to another peer Presentation Layer: The presentation layer, layer-6, takes the data supplied by the lower

level layer and transform so it can be presented to the system Application Layer: The Application layer, layer 7, controls how the operating system and its

application interact with network.

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FIBER OPTIC TRANSMISSION SYSTEM

INTRODUCTION:

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.

Another important application for optical fiber is the biomedical industry. Fiber-optic systems are used in most modern telemedicine devices for transmission of digital diagnostic images. Other applications for optical fiber include space, military, automotive, and the industrial sector The high bandwidth provided by fiber makes it the perfect choice for transmitting broadband signals, such as high-definition television (HDTV) telecasts. Optical fiber is also used extensively for transmission of data. Multinational firms need secure, reliable systems to transfer data and financial information.

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.

• MAINTENANCE: Fiber optic cables costs much less to maintain.

CLASSIFICATION:

There are three types of fibers:

1.STEP-INDEX MULTIMODE FIBER: It has a large core, up to 100 microns in diameter This type of fiber is best suited for transmission over short distances, in an endoscope, for instance.

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2. GRADED-INDEX MULTIMODE FIBER: It contains a core in which the refractive index diminishes gradually from the center axis out toward the cladding.

3. SINGLE-MODE FIBER: It has a narrow core (eight microns or less), and the index of refraction between the core and the cladding changes less than it does for multimode fibers

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,

following the transmission sequence give below :

(1) Information is encoded into Electrical Signals.

(2) Electrical Signals are converted into light Signals.

(3) Light Travels down the Fiber.

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

(5) Electrical Signals are decoded into Information.

Propogation of light through Fibre.

Jacket

Cladding

Core

Cladding

Angle of

reflection

Angle of

incidence

Light at less than

critical angle is

absorbed in jacket

Jacket

Light is propagated by

total internal reflection

Jacket

Cladding

Core

(n2)

(n2)

Fig. Total Internal Reflection in an optical Fibre

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MOBILE COMMUNICATION

A mobile phone uses radio wave signal for its connectivity with the subscriber.

The mobile phone works on the frequency signal and each mobile phone connection has its

own frequency. These frequencies are sending from the basic lower station tower. Each tower

has a range of 5 km in the city circle and there are a number of towers in the city to provide

connectivity to each mobile phone subscriber.

Components of Mobile Communication:

MOBILE STATION (MS):

A mobile unit is a transmitter as well as receiver too. It has a SIM (Subscriber Identity

Module) which gives a unique identity of a subscriber. Every mobile unit has a unique

IMIEI(International Mobile Equipment Identity) number.

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BASE TRANSCEIVER STATION (BTS):

A base transceiver station or cell site (BTS) is a piece of equipment that facilitates

wireless communication between user equipment (UE) and a network.

It encodes, encrypts, modulates and feeds the RF signal to antenna.

It produces time and frequency synchronization signals.

It does power control and frequency hopping too.

BASE STATION CONTROLLER (BSC):

Its main work is to control several transceivers.

Switching between BTSs

Managing of network resources

Mapping of radio channels

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NETWORK AND SWITCHING SUBSYSTEM:

This subsystem does mainly switching, mobility management, interconnection to other

networks, system control.

COMPONENTS:

1. MOBILE SERVICES SWITCHING CENTRE (MSC):

It controls all connections via a separated network to/from a mobile terminal within the

domain of the MSC – several BSC can belong to a MSC.

FUNCTION OF MOBILE SWITCHING CENTER (MSC):

Manages communication between GSM and other network (PSTN, Data Network and

GPRS).

Call setup basic switching, call handling.

Billing for subscriber.

2. DATABASES:

Home Location Register (HLR):

Central master database containing user data, permanent and semi-permanent data of all

subscribers assigned to the HLR (one provider can have several HLRs).

Visitor Location Register (VLR):

Local database for a subset of user data, including data about all user currently in the domain

of the VLR.

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GLOBAL SYSTEM FOR MOBILE COMMUNICATION (GSM)

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.

FEATURES OF GSM:

GSM is already used worldwide with over 450 million subscribers.

The availability of Subscriber Identity Modules, which are smart cards that provide secure

data encryption give GSM m-commerce advantages.

GENERAL PACKET RADIO SERVICE (GPRS)

General packet radio service (GPRS) is a packet oriented mobile data service available to

users of the 2G cellular communication systems, global system for mobile communications

(GSM), as well as in the 3G systems. In 2G systems, GPRS provides data rates of 56-114

kbps GPRS extends the GSM circuit switched data capabilities and makes the following services

possible:

“ Always on” Internet access

Multimedia messaging service (MMS)

Push to talk over cellular (PoC/PTT)

Point to Point (P2P) service: inter-networking with the internet (IP).

Increase message sending speed 30 messages per minute approximately.

CODE DIVISION MULTIPLE ACCESS (CDMA)

Code Division Multiple Access (CDMA) consistently provides better capacity for voice and

data communications that other commercial mobile technologies, allowing more subscribers

to connect at any given time, and it is the common platform on which 3G technologies are

built.

CDMA is a spread spectrum technology, allowing many users to occupy the same time and

frequency allocations in a given band/space

ADVANTAGES 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.

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DIFFERENCE BETWEEN CDMA AND GSM:

The GSM stands for global system for mobile communication and CDMA for code

division multiple accesses.

GSM is a form of multiplexing, which divides the available bandwidth among the

different channels. Most of the times the multiplexing used are either TDM (Time

Division Multiplexing) or FDM (Frequency Division Multiplexing). On the other

hand CDMA is a type of multiple access scheme (which means allotting the given

bandwidth to multiple users) and makes use of spread spectrum technique which is

essentially increasing the size of spectrum.

FDMA (Frequency Division Multiple Access): Where individual transmission

separated by each other by the time.

WIRELESS IN LOCAL LOOP (WLL) MOBILE:

WLL is a communication system that connects customers to the Public Switch Telephone

Network (PSTN) using radio frequency signals as substitutes of conventional wires for all

part of connection between the subscribers and the telephone exchange. It works on CDMA

technique. There is no standard for this so far. However, a number of national and international air

interface standards for digital cellular mobile telephone system are available.

CONCLUSION

The working in the project was an interesting and an all together learning experience. New

technologies, new progress and new competition are the order of the day. The core area to

look for is highly fragmented and information intense activity sequence that involves a

number of player and audiences.

The project mainly revolves around: EWSD, TAX, internet node, mobile communication,

WLL and intelligence network.

The emphasis of the different parts of the project is to throw light on the systems working in

Patna Main Exchange. The project also deals with modern technologies attributes and the

scope of implementation of the same in Patna. The area under study was limited to Patna

Main Exchange.

The scope of the study is very vast and the topic under study deals with the volatile

technology world. After the study, suggestions and strategy has been formulated keeping in

view the limitations of the field.

Evolution of this technological world is occurring every minute. Thanks to telecom and web

technologies, countries are coming closer day by day.

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REFERENCES

1. Data Communication And Networking- Behrouz A. Foruzan

2. Wireless Communication and Networks-William Stallings

3. Computer Networking – Kurose & Ross

4. www.bsnl.co.in

5. www.newbsnl.co.in

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