Download - Vikram Thakur 803043

7/31/2019 Vikram Thakur 803043

1/23

SEMINARINDUSTRIAL TRAINING

By Vikram Thakur

ECE 7th Sem

803043


2/23


3/23

BSNL Provides the Services as:


4/23

COMPANY PROFILEBSNL

C.DOT

The Center for Development of Telematics (C-DOT) is the telecom

technology development center of the government.

It was established in August 1984

To design and develop state of the art technologies, products and

solutions

To meet the telecom needs of India, particularly of national

importance in strategic sectors and rural areas


5/23


6/23

Making a telephone call


7/23

Make a telephone call

A telephone call starts when the caller lifts the handsets of the base. Once

the dial tone is heard, the caller uses a rotary or a push button dial mounted

either on the handset or on the base to enter a sequence of digits, the

telephone number of called party.

The switching equipment from the exchange removes the dial tone from theline after the first digit is received and after receiving the last digit, determines

the called party is in the same exchange or a different ones.

If party is in the same exchange or a different ones. If the called is in the

same exchange, burst of ringing current is applied to the called partys line.

If the called party is in different exchange from the caller, the caller exchangeset up the connection over the telephone network to the called partys

exchange.

Its the general process a Telephone Exchange do During

call.


8/23

Architecture of Exchange

A Main Distribution Frame (MDF)

Modules (Computer Room)

Power Plant


9/23

It is a signal Distribution Frame for connecting equipment (Inside

Plant) to cables and Subscriber Carrier equipment (Outside Plant).

The MDF is a termination point within the local Telephone Exchange

where exchange equipment and terminations of Local Loops are

connected by jumper wires.

The MDF usually holds Central Office protective devices

including heat coils and functions as a test point between a line and

the office.

Jumper used in MDF is a twisted wired pair.


10/23

Fig: A Practical Main Distribution Frame


11/23




Power Plant


12/23

C.DOT exchange has Four Modules

Base Module

Central Module

Administrative Module

Input Output Module


13/23

Base Module

The Basic functions of a base modules are:-

Analog to digital conversion of all signals on analog lines and trunks.

Interface to digital trunks and digital subscriber.

Switching the calls between terminals connected to the same Base Module.

Communication with the AM via the CM for administrative(i.e. Call

processing ) functions.

Provision of special circuits for call processing support e.g. Digital

Tones, announcement, MF/DTMF Senders/receivers.

Provision for local switching Unit(RSU) as well as in case of Single Base

Module Exchange

It is of two types:1. Single Base Modules(SBM)

2. Multi Base Module(MBM)


14/23

Fig General frames Diagram of Base module


15/23

Central module

Central module is responsible for

space switching of inter-Base Module calls,

communication between Base Module and Administrative Modules,

clock distribution and network synchronization.

CM Hardware is distributed in following frames : -

Bus Terminal Unit (BTU) Frame

Space Switch Unit (SSU) Frame

Space Switch Controller Unit (SCU)Administrative Processor Unit (APU)


16/23


17/23

Administrative Module

Status of all module of the exchange is maintained by the AP and whenever a problem

is reported required action is initiated to clear the problem. All the global resource like

trunks. Time slots etc are managed by the A.P. Directory to equipment number

translation for the establishment of a call is performed by AP

All global data is managed by the AP. In a multimodule exchange all thecall processing. Administration and maintenance function are supervised by the

AP.


18/23

Function of APU : - All administrative function in the system Interaction with SSC through central message switches CMS(A,B) (SSC/BM to

IOP via AP).

Communication to ADP.

Administrative Processor (AP) somewhat similar to BP.

Maintain status of all modules of the exchange.

Initiate whenever a problem is reported required action to clear the problem. Switch over of copies, diagnostic of faulty units and put in service units which

are out of service etc, are initiated and supervised by the AP.

Manage all the global resource (like trunks,ts etc.)

Perform directory to equipment no. translation for the established of a call.

Connects of exchange to the operator through IOP.

Handle the man-machine communication.

During initialization of the multimode exchange AP gather initialization requestfrom different BMs, collects code and data from IOP and send it tocorresponding BMs.


19/23




Power Plant


20/23

POWERPLANTAs 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 isthe input.

The main source of this exchange is AC supply. However, as soon as the

power supply is gone off, then what is source? No one think on this that the

telephone is always plays its role in the human life. Even if the power supply

gone off. Thus there must be adjustment source of power.

The main parts of the power room are:

Batteries: - these are the instant sources of the power as soon as power isgone off.

UPS (Uninterrupted Power Supply):-the UPS must give supply to thecomputer. As we know there is some equipment which can withstand any type

of power supply, but there are also some instruments which cannot withstand

with this type of power supply, even a microsecond delay will cause the loss of

data.


21/23

Inverter and Converter Unit: - the main use of thissystem is to change AC mains to DC and vice versa as

required by the parts of exchange.

Engine Room:-we know that the batteries are the instantsource of supply but we cannot use it for much larger

time, thus for this, we have an engine to generate the

power supply. They are of 885 KVA. Thus, this room

controls the supply of the engine.


22/23

ConclusionI would like to conclude this training as a very great and enriching experience tointeract with the interesting field in the name of C.Dot BSNL Exchange.

Thus the all things which occurs in telephone Exchange is

Origination : - Origination begins when the subscriber line goes off hookorincoming trunks seized. It receives the incoming digits, selects the digit analysis

tables, and determines the screening information for this call.

Digit Analysis: - It interprets the digits it receives from origination ,select adestination for each call, and passes the dialed digits to routing.

Routing/Screening:- Routing uses the destination information from digit

analysis and screening information origination to select the terminating trunk group

or line.

Charging : - It uses the charging information from routing to expand thecharging data into a formate usable by call accounting process.

Termination : - The last step in call processing is termination. TerminationProcessor is different for calls destined for lines and call destined for trunks.


23/23

Thanks

Download - Vikram Thakur 803043

Top Related