DEPARTMENT OF ELECTRONICS AND COMMUNICATION

O/o TDM, BSNL, BettiahPin- 845438, Bihar; Ph.-06254-246000

Session 2016-17SUBMITTED BYRANJAN KUMAR

GUPTAECE – 4th year

1322231055

SUBMITTED TODEPARTMENT OF ELECTRONICS

ANDCOMMUNICATIONSEPTEMBER 2016

INTRODUCTION

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.

 

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.   

WORKING OF BASIC TELECOMMUNICATION NETWORK

Parts of a Telecommunication network

The main parts of a Telecommunication network are:

1.Telephone Exchange2.Main Distribution Frame (MDF)3.Switch Room

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

About the exchange

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-DOT2. OCB(ORGANE DE COMMANDE B2 VERSION)3. EWSD

             C-DOTIt work on telecom technology, products and services. 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.

   OCB(ORGANE DE COMMANDE B2 VERSION)It is a digital switching system.The system supports all the existing signaling system.The system has ‘auto recovery’ feature. When a serious fault occur in control unit, it gives a message to SMM (operation & maintenance unit).      

 OCB(ORGANE DE COMMANDE B2 VERSION)

EWSDThe EWSD Digital Switching Systems offer a wide range of telephony features and supplementary services. Further capabilities can be developed to meet specific customer needs.

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

MAIN DISTRIBUTION FRAME(MDF)

Structure Of MDF

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

Switch RoomSwitch room consists of BM(Benjamin Moore) and CM cabinets mounted in standard switch.

These cabinets are fastened to a switch Room and interconnected by cables

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 Computer2.ADSL Modem3.Land Line Connection 4.Splitter for separating telephone from Personal computer5.High speed Internet Access: This is the always-on Internet access service with speed ranging from 256 kbps to 8 Mbps.    

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.

FTTHFTTH 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.

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 connectionData Link Layer: the data link layer, layer 2, defines standard that assign meaning to the bits carried by the physical layerNetwork 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 peerPresentation Layer: The presentation layer, layer-6, takes the data supplied by the lower level layer and transform so it can be presented to the systemApplication Layer: The Application layer, layer 7, controls how the operating system and its application interact with network.

IPv4 Addressing

This section covers some of the basic concepts of IPv4 addressing, such as how the Internet's address architecture uses the binary and dotted-decimal versions of IPv4 addressing. This section also reviews the structure of IPv4 addresses, such as the various classes of IPv4 . 32-bit IP addresses are written using dotted-decimal notation. Each 32-bit address is divided into four groups of eight, called octets. Each octet is converted to decimal and then separated by decimal points, or dots.Bit IP addresses are written using dotted-decimal notation.

A 32-bit IP address is a binary number:10101100000111101000000000010001This binary number can be divided into four octets:10101100 00011110 10000000 00010001Each octet (or byte) can be converted to decimal:172 30 128 17Finally, the address can be written in dotted-decimal notation:172.30.128.17

Various classes of IPV4 address

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

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.

Jacket

CladdingCore

Cladding

Angle of reflection

Angle of incidence

Light at less thancritical angle isabsorbed in jacket

Jacket

Light is propagated by total internal reflection

Jacket

Cladding

Core

(n2)(n2)

Fig. Total Internal Reflection in an optical Fibre

GLOBAL SYSTEM FOR MOBILE COMMUNICATION

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.

GSM frequencies

• 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.

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 securitySimultaneous conversationsLow power requirements and little cell-to-cell coordination needed by operators.Extended reach-beneficial to rural users situated far from cells. 

GSM Network Architecture

MS

BTS

BTS

BTS

BTS BTS

BTS

BTS

BTS

BSC

BSC

PSTN

VLR

TRAU HLREIR

OMC

SMSC

BC

AUC

VMSC

MSC

Abis

A

OML

Mobile Station (MS)

• MS refers to the physical phone itself uniquely identified by the International Mobile Equipment Identity (IMEI) number.• SIM(Subsciber 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.

IMEI

• Barring of a subscriber by the operator does not bar the mobile equipment. To prevent that kind of misuse, every GSM terminal equipment contains a unique identifier, the international mobile equipment identity (IMEI).

International Mobile Equipment Identity (IMEI)

Type ApprovalCode

TAC FAC SNR SP

Final AssemblyCode

Serial number (SPare)

TYPE

APPROVED

IMEI: * # 0 6 #351475 60 926514 4

BILLING SYSTEM

INTRODUCTION TO    BILLING SYSTEM

Billing Centers

• Four Billing Zones• South Zone• North Zone• East Zone• West Zone

SOUTH ZONE

NORTH ZONE

EAST ZONE

WEST ZONE

Thanks