Assignment Report

ONSUBMITTED DURING THE VOCATIONAL TRAINING AT BSNL DURG

  Under the Guidance of

SMT. VASUMATHY (SDE) Submitted by

1. Virendra pal kosale2. Pragya sagne3. Sonali ghosh

DATE: 25/06/2014

ASSIGNMENT

TEAM Assignment Title: OCB Technology Batch: 02 Semester: 4th

Collage: CCET Bhilai

Project Leader: NAME: Virendra pal kosale

NAME: Pragya sagnePhone: 9691556715 Email: pragyasagne21@gmail.com

NAME: Sonali ghoshPhone: 9425292715Email sonali.ghosh1992@gmail.com

Phone: 7805092939

Email: vpkosale2401@gmail.com

Project Members:

We hereby declare that the Assignment entitled “ OCB Technology ” being submitted in partial fulfillment for the certificate for vocational training to “Bharat Sanchar Nigam Limited, Durg” is

the authentic record of our own work done under the guidance of SMT. VASUMATHY (SDE),

 

DECLARATION

Assignment Members

Name: Signture1. Virendra pal kosale2. Pragya sagne3. Sonali ghash

ACKNOWLEDGEMENT

First & foremost, we thank Almighty God for giving me this unique opportunity to express my heartfelt gratitude to all those who have extended helping hands to make this study success. We have a great pleasure in expressing my deep sense of gratitude to SMT. “VASUMATHY” ,(S.D.E). without whose help we would never have achieved completion in our work. With due regards we feel immense pleasure in expressing our deepest gratitude to our amiable parents & friends whose filial affection, encouragement & blessing have been a beacon light to us in all undertakings.

Submitted by :

1. Virendra pal kosale 2. Pragya sagne3. Sonali ghosh

DATE: 25/06/2014PLACE: Durg

CERTIFICATE

This is to certify that Virendra pal kosale a student of Electronic and Telecommunication Branch of

Christian collage of Engineering & Technology Bhilai College has successfully completed a assignment on the topic-“OCB Technology” on 25th June.,2014 & submitted the report on the same, under the guidance of guides

SMT.VASUMATHY S.D.E.( )

Signature of Guide

CERTIFICATE

This is to certify that Pragya Sagne a student of Electronic & Telecommunition a Branch of SSCET Bhilai College has successfully completed a assignment on the topic-“OCB Technology” on 25th June.,2014 & submitted the report on the same, under the guidance of guides

SMT.VASUMATHY , S.D.E.( )

Signature of Guide

CERTIFICATE

This is to certify that Sonali ghosh a student of Electronic and Telecommunication Branch of P.C.E

Nagpur College has successfully completed a assignment on the topic-“OCB Technology” on 25th June.2014 &

submitted the report on the same, under the guidance of guides SMT.VASUMATHY S.D.E.( )

Signature of Guide

TOPIC PAGE NO.

1. COMPANY PROFILE2. INTRODUCTION3. ABOUT THE EXCHANGE4. MDF5. TYPES OF FAULTS5. PROTECTIVE DEVICES5. OCB 6. GSM7. MEDIA8. PROCEDURE FOR HANDLING COMPLAINTS

INTRODUCTION

Today, BSNL is the No. 1 telecommunication company and the largest public sector undertaking of India and its

responsibilities includes improvement of the already impeccable quality of telecom services, expansion of

telecom services in all villages and instilling confidence among its customers.

EXCHANGE:

Equipment which effects interconnected of telephones is known as switching equipment.

The switching centre, which houses the terminating and switching equipment is called

telephone exchange.

EXCHANGE LAYOUT

 

Typical exchange consist of :

Switch Room Operations and Maintenance (OMC) Room

Input Output processor (IOP) Room Power Plant Room

Battery Room Main Distribution Frame (MDF) Room

ABOUT THE EXCHANGE

1. All telephone subscribers are served by automatic exchanges.

2. Today’s automatic exchanges uses 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:

> C-DOT> OCB

> EWSD

MAIN SECTIONS OF EXCHANGE:

There are three components of exchange: MDF Power plant Switching Room.

Main Distribution Frame (M.D.F) :

INTRODUCTION:

- MDF means Main Distribution Frame. Local cable contact at MDF . - All types of cables out to the door contact connection at MDF .

The main parts of the power room are:

1. Batteries

2. UPS (Uninterrupted Power Supply)

3. Charging - Discharging Unit

4. Inverter and Converter Unit:

POWER PLANT :

SWITCHING ROOM :

Switch room consists of BM and CM cabinets mounted in standard switch.

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

.

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 in the MDF because of some specific reason.

ORGANISATION OF THE 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 core1 core = 4 bunch1 bunch = 2 lineN.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 is placed in jack strips, which is connected to telephone for checking.

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.

CONSTRUCTION OF M.D.F:-

Main distribution frame is mainly divided in two parts.

(1) Vertical Side or Line side.

(2) LEN side or Exchange side.

VERTICAL SIDE:

All the part from vertical side to the subscriber are generally called 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

LEN SIDE:

• All the parts from LEN to the exchange is called indoor section.

• 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.

DIFFERENT TYPES OF FAULTS

LOOP FAULT:-If two wires are joined together because of improper connection,storming air etc.

EARTH FAULT:-If two wires get scrape at some places and if this wire comes incontact with tree, pillar or any metal objects then this type of fault occurs.

CABLE FAULT:-For outdoor connections, jelly filled wires are used which are affected by natural causes such as rain, earthquake etc. At such time this fault occurs.

DISCONNECT FAULT:-This type of fault occurs due to the breaking of wires between the vertical side & LEN side.

PROTECTIVE DEVICES USED IN M.D.F.

Fuses

Gas Discharge Tube(G.D Tube)

Insertion Tool

Wires

OCB

The new switching systems are based on Stored Program Control 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 . Salient 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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TIME SWITCH CONCEPT

• The time switch comprises of a Speech Buffer Memory, A ControlMemory, An Incoming Highway Of Digital Speech In Parallel Bits and An Outgoing Highway. This is an Input Associated Controlled Time switch. In this switch the Buffer Memory and Control Memory are controlled write type i.e. the writing in it is controlled. The control function writes in the control memory at the location corresponding to the Incoming Time Slot Number, the location where it should be written in the Buffer Memory. Both these memories are sequential read type. Reading of control memory gives the address in the Buffer Memory for writing Incoming TS Byte. Thus reading of Buffer Memory sequentially the TS will be read from the location given by the Control Memory. Thus a one way Time switching has taken place. Similarly a both way switching requires two sets of such switches.

DUPLICATE SWITCHING• The switching is done in OCB-283 in two fully duplicated

branchessimultaneously. For this purpose from each connection units the LR linksoriginate in two parallel branches towards two parallel sets of switching matrices called SMX A and SMX B. The branches of such network are called A and B branches. Also the receive side LR links come from both the SMX’s A & B and are terminated on the respective connection units. The duplicated branches of switching have been designed to provide high reliability switching path for suchdiverse purposes as data switching, video conference, ISDN applications etc.With the duplicated paths of switching if there is error in one path the other path which is good can be used continuous without interrupting the call in progress.

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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 mobile phones connect to it by searching for cells in the immediate vicinity. GSM operates in the 900 MHz frequency band.

There are five different cell sizes in a GSM network-

Macro Cells Micro Cells Pico Cells Femto Cells Umbrella Cells

GSM : (SYSTEM ARCHITECHTURE)

This system structured hierarchically as shown: • It consist of one administrative region, which is assigned to a

MSC(Mobile Switching Center).• Each administrative Region is made up of atleast one Location Area(LA).

LA is also called the visited area.• An LA consists of several cell groups.• Each cell group is assigned to a base station controller(BSC).• Cells of one BSC may belong to different LA’s.

GSM : (SYSTEM ARCHITECHTURE)

BASIC BUILDING BLOCKS:

Mobile Station (MS)

Base Station (BS)

Mobile services Switching Center (MSC)

Databases

Operation and Maintenance Center (OMC)

SYSTEM CAPACITY

• Shannon’s 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 noise – like & min SNR.

• Hence for increased capacity the choice is CDMA.

Media : -

1.Carrier system

2. Co-axial Cable

3. Optical Fiber Cable(OFC).

4. Satellite.

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 ):

> PERMANENT RING

> PERMANENT DIAL TONE

> PERMANENT BUSY TONE

> PERMANENT RING – TRIP

 > SPEECH QUALITY POOR  > WRONG NUMBERS  > ONE WAY SPEECH

> RINGER CADENCE

THANK YOU