A project on report ocb switching

8/12/2019 A project on report ocb switching

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SUMMER TRAINING REPORTHELDAT

BSNL


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INDEX

1. COMPANY PROFILE

2. INTRODUCTION

3. ABOUT THE EXCHANGE

4. MDF

>TYPES OF FAULTS

>PROTECTIVE DEVICES

5. OCB

6. GSM

7. MEDIA

8. PROCEDURE FOR HANDLING COMPLAINTS


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INTRODUCTION

Today, BSNL is the No. 1 telecommunication company and thelargest public sector undertaking of India and its responsibilitiesincludes improvement of the already impeccable quality oftelecom services, expansion of telecom services in all villages andinstilling confidence among its customers.

EXCHANGE:

Equipment which effects interconnected of telephones is knownas switching equipment.

The switching centre, which houses the terminating and switchingequipment is called telephone exchange.


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EXCHANGE LAYOUT

Typical exchange consist of :

Switch Room

Operations and Maintenance (OMC) RoomInput Output processor (IOP) Room

Power Plant Room

Battery Room

Main Distribution Frame (MDF) Room


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ABOUT THE EXCHANGE

1. All telephone subscribers are served by automaticexchanges.

2. Todays automatic exchanges uses a pair of computers.

One, running the program that provides services.

Second, monitoring the operation of the first, ready totake over in a few seconds in the event of equipmentfailure.

Various exchanges present in BSNL are:

> C-DOT> OCB> EWSD


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MAIN SECTIONS OF EXCHANGE:

There are three components of exchange:

MDF

Power plant

Switching Room.


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MAINDISTRIBUTIONFRAME(M.D.F) :

INTRODUCTION:

- MDF means Main Distribution Frame. Local cablecontact at MDF .

- All types of cables out to the door contactconnection at MDF .


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THEMAINPARTSOFTHEPOWERROOMARE:

1. BATTERIES

2. UPS (UNINTERRUPTEDPOWERSUPPLY)

3. CHARGING- DISCHARGINGUNIT

4. INVERTERANDCONVERTERUNIT:

POWER PLANT :


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SWITCHING ROOM :

Switch room consists of BM and CMcabinets mounted in standard switch.

These cabinets are fastened to a switchRoom and interconnected by cables.


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.

MAIN DISTRIBUTION FRAME

> The primary function of MDF is to remove fault. It

is also known as Fault Remove Section.

> The telephone numbers are also disconnected inthe MDF because of some specific reason.

ORGANISATION OF THE MDF

Vertical sideHorizontal side


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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 core1 core = 4 bunch

1 bunch = 2 line

N.E.:-The word NE stands for the NUMBER OF EQUIPMENT.

It is used for testing number and

WEDGE: Wedge is used as a device for checking the ring. Wedge isplaced in jack strips, which is connected to telephone for checking.


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HORIZONTAL SIDE:

The horizontal side connected to the underground cable.This cable is having 100 pairs. These pair is distributed

when we 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.


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CONSTRUCTION OF M.D.F:-

Main distribution frame is mainly divided intwo parts.

(1) Vertical Side or Line side.

(2) LEN side or Exchange side.


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VERTICAL SIDE:

All the part from vertical side to the subscriber are generallycalled outdoor section.:

1. One vertical has 10 tag blocks.

2. Each tag block has 10 rows and each row has 10 tags. So

each tag block has 100 tags.

3. Connection between vertical side & subscribers are

provided by jelly filled cables.

4. These wires are first terminated in cabinet box, then

according to requirements the group of the wires (e.g. 200

wires, 100 wires etc.) is terminated in pillar box


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LEN SIDE:

All the parts from LEN to the exchange is called indoorsection.

The connection of subscriber from exchange is

terminated on this side of MDF.

In 1 tag block there are 128 tags. Each tag block is

divided in 4 segments. That is 0, 1,2 & 3 and in each

segments.


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.DIFFERENT TYPES OF FAULTS:-

LOOP FAULT:-IFTWOWIRESAREJOINEDTOGETHERBECAUSEOFIMPROPER

CONNECTION,

STORMINGAIRETC.

EARTH FAULT:-IFTWOWIRESGETSCRAPEATSOMEPLACESANDIFTHIS

WIRECOMESINCONTACTWITHTREE, PILLARORANYMETALOBJECTSTHENTHISTYPEOF

FAULTOCCURS.

CABLE FAULT:-FOROUTDOORCONNECTIONS, JELLYFILLEDWIRESARE

USEDWHICHAREAFFECTEDBYNATURALCAUSESSUCHASRAIN, EARTHQUAKEETC. ATSUCHTIMETHISFAULTOCCURS.

DISCONNECT FAULT:-THISTYPEOFFAULTOCCURSDUETOTHEBREAKING

OFWIRESBETWEENTHEVERTICALSIDE& LEN SIDE.


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PROTECTIVE DEVICES USED IN M.D.F

.

Fuses

Gas Discharge Tube(G.D Tube)

Insertion Tool

Wires


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OCB

The new switching systems are based on Stored ProgramControl concept. The call processing programmers are

distributed over different control organs of the system and are

stored in ROM/RAM of the units Processor in the control units

.

Features:

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).


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GLOBAL SYSTEM FOR MOBILE COMMUNICATION

GSM)

Global system for mobile communication (GSM) is a globally

accepted standard for digital cellular communication. GSM is

the name of a standardization group established in 1982 to

create a common European mobile telephone standard

GSM is a cellular network which means that mobilephones connect to it by searching for cells in the immediate

vicinity.GSM operates in the 900 MHz frequency band.


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THEREAREFIVEDIFFERENTCELLSIZES INA

GSM NETWORK-

Macro CellsMicro CellsPico CellsFemto Cells

Umbrella Cells


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GSM : (SYSTEM ARCHITECHTURE)


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BASIC BUILDING BLOCKS:

Mobile Station (MS)

Base Station (BS)

Mobile services Switching Center (MSC)

Databases

Operation and Maintenance Center (OMC)


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SYSTEM CAPACITY

Shannons Theory predicts the maximum amount of

information that can be transmitted over a channel with

given BW & SNR.

The optimum usage of given BW is obtained when the

signal are noiselike & min SNR.

Hence for increased capacity the choice isCDMA.


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MEDIA: -

1.Carrier system

2. Co-axial Cable

3. Optical Fiber Cable(OFC).

4. Satellite.


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PROCEDURE FOR HANDLING

SUBSCRIBER COMPLAINTS

Telephone Dead:

Case--I Problem concerns a particular subscriber.Case-II Quit a few numbers of telephone reported dead:

Telephone Held-Up ( No Dial Tone ):


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> PERMANENT RING

> PERMANENT DIAL TONE

> PERMANENT BUSY TONE

> PERMANENT RINGTRIP

> SPEECH QUALITY POOR

> WRONG NUMBERS

> ONE WAY SPEECH

> RINGER CADENCE


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THANK YOU

Documents

A project on report ocb switching