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MAJOR TRANINGREPORT

FROM BSNL ON

TELECOMMUNICATION


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CONTENTS:-1)BSNL ORGNAISATION2) HOW TO SUBSCRIBER COMMUNICATE3) TELEPHONE EXCHANGE & SWITCHES

4) TRANSMISSION SYSTEM OR MODESa) SDHb) PCM

5) GSMa) BSSb) MSS

c) NSS6) CDMA7) 3G8) MAIN DISTRIBUTION FRAME9) CHANNEL OVERVIEW


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B.S.N.L. Organization

Bharat Sanchar Nigam Ltd. formed in October, 2000, isWorld's 7th largest Telecommunications Company providingcomprehensive range of telecom services in India: Wireline,CDMA mobile, GSM Mobile, Internet, Broadband, Carrierservice, MPLS-VPN, VSAT services, IN Services etc. Within aspan of five years it has become one of the largest publicsector unit in India.


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TELEPHONE EXCHANGE

INTRODUCTION

The main function of an exchange is to process call from acalling subscriber and make the connection to the calledsubscriber. This connection can be direct or via another exchange.This requires all parts of the exchange to work as a unit to ensurethe call is properly handled.


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CALL PROCESSING ARCHITECTURE

The main function of the exchange is to process subscriber calls.The exchange does this by connecting an incoming line or trunk to another line or trunk. However call processing involves muchmore than simply connecting subscribers. In order to process thecalls the exchange must perform four basic switching functions.

S upervision:D etects and reports service requests, acknowledgements and

requests to terminate service.S ignaling:Transmits information about lines and trunks and information

about other aspects of call handling to control switchingequipment.

Routing:Converts address information to the location of the

corresponding call line or to the location of a trunk on the way tothat line.


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CALL PROCESSING STAGES


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M ODES OF TRANSMI SSION:-

SDH (SYNCHRONOUS DIGI TAL HERARCHY)

INTRODUCTION:

It is an international standard networking principle and amultiplexing method. The name of hierarchy has been taken fromthe multiplexing method which is 4 synchronous by nature. Theevolution of this system will assist in improving the economy of operability and reliability of a digital network .


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M ERITS OF SDH:

Simplified multiplexing/demultiplexing techniques.

II. Direct access to lower speed tributaries, without need tomultiplex/demultiplex the entire high speed signal.

E nhanced operations, Administration, Maintenance & provisioningcapabilities.

Capable of transporting existing PDH signals.Capable of transporting future broadband channel bit rates.Capable of operating in a multi-vendor and multi-operator

environmentADVANTAG ES:

SDH supports the following services:Low/High speed data.VoiceInterconnection of LANComputer linksBroadband ISDN transport


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Pulse -cod e mod ul ation.

P ulse code modulation ( P CM) is a digital scheme for transmittinganalog data. The signals in P CM are binary; that is, there are onlytwo possible states, represented by logic 1 (high) and logic0 (low).This is true no matter how complex the analog waveform happens to

be. Using P CM, it is possible to digitize all forms of analog data,

including full-motion video, voices, music, telemetry, and virtualreality (VR).To obtain P CM from an analog waveform at the source (transmitter end) of a communications circuit, the analog signal amplitude issampled (measured) at regular time intervals. The sampling rate, or

number of samples per second, is several times the maximumfrequency of the analog waveform in cycles per second or hertz .


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QuantizationDone tomake thesignal

amplitudediscrete

Addsquantization

noise


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GSM Cell Structure


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ALLOCATED G SM FREQUENCY BANDS


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F eatures of GSM

Compatibility N oise RobustF lexibilityIncreased CapacityImproved S ecurityISD N CompatibilityConfidentialitySubscriber IdentificationUse of S tandardized O pen Interface

E nhanced Range of S ervicesCleaner HandoversInternational Roaming Capability


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3 G

A telecommunication hardware standards and general Technologyfor mobile networking .

It is based on the International Telecommunication Union (ITU)family of standards

It conceived from Universal Mobile Telecommunication S ervice(UMT S ) concept for high speed networks for enabling variety of data intensive applications

It consists of two main standards C D MA 2 000 & w- C D MA3G network operators offer wide range of advanced service to its

usersThis can be achieved by S pectral efficiency


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3G CDMA ARCHITECTUR


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M AINDISTRIBUTION FRAM E:-

M ain Di s trib u tion Fram eM.D.F. is a media between switching network and subscriber sline. It distribute wires in different areas and this wire connectswitching room and subscribers line.


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10 . Logica l Chann els

Traffic Channels (TCH) TCH/ F and TCH/H for full and half rate speech channels. TCH/9.6, TCH/4.8 and TCH/ 2 .4 for 9.6, 4.8 and 2 .4 kb/s datachannels.

B roadcast Channels ( B CH) F requency correction channel ( F CCH), S ynchronization channel ( S CH), B roadcast control channel ( B CCH).

Common control channels paging channel ( P CH), A ccess grant channel ( A GCH), Random access channel (R A CH).

D edicated control channels S tand-alone dedicated control channel ( SD CCH), S low associated control channel ( S A CCH),


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