mtnl summer training presentation

8/10/2019 MTNL Summer Training Presentation

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SUMMER TRAINING ATThe Institute of Telecom Technology &

ManagementNAME: ASHRAY SAWHNEY

ROLL NO. : 05070102811

B.TECH(ECE)VII SEMESTER

SWITCHING



CONTENT

ABOUT ITTM

INTRODUCTION

BASIC TERMINOLOGY OCB-283

DIGITAL SWITCHING



ABOUT ITTM

The Institute of Telecom Technology &Management, IITM (formerly DTTC), Shadipur is astate of the art training center of MTNL, Delhiengaged in imparting induction training and shortduration trainings to its officers and employees in

the field of Telecom, IT, Computer systems andManagement.

The students are imparted classroom lectures onthe latest in Telecom Technologies and IT (4weeks) followed by intensive field training and

exposure to the latest in Telecom Technology(2weeks).



Classroom topics include Introduction toTelephony, Switching Technology, MDF andProtective Devices, Overview of External plant,Transmission basics, Optical fibre systems (SDH &FTTH), Data Communication & IP networks,Broadband concepts, Technology & serviceaspects, GSM, CDMA & 3G Overview and alsoHRD topics such as Communication skills, Stress

Management & Time Management.

Students are offered field training at any location/ Exchange based on their preferences and thedesired field. Students get the opportunity to visit& have hands on training on the latest in Telecom

Technology & IT.



INTRODUCTION

Switch:

Control consisting of a mechanical or electrical or

electronic device for making or breaking orchanging the connections in a circuit.

And the process is called SWITCHING.



WHY SWITCHING IS REQIRED??

Whenever the number ofcustomers are more thanresources available, switchingis required.

SIGNALLING CONTROLSWITCHING

Control

123

N

12

3

N

Connectionof inputsto outputs …

…



TECHNOLOGIES USED IN

MTNL 5ESS (ALCATEL)

EWSD (Siemens)

AXE-10 (Ericsson) OCB-283 (ALCATEL)



OCB 283

O-------- ORGAN

C-------- COMMAND OR CONTROL

B-------- BHERSION

2--------- IIND GENERATION

83------ 8300 Motorolla MICROPROCESSOR UNIT



OCB 283 is digital switching system

which supports a variety ofcommunication needs like basictelephony, ISDN, interface to mobile

communication, datacommunication.

Developed by CIT ALKATEL, France .



•First OCB 283 exchange of R11

version were commissioned inBrest (France) and Beijing (China)in 1991.

•First OCB-283 exchange came toIndia in 1993.



OM MQ GX MR TX TR PC

COMETA

PU

PE

SMT

URM

MCX

CSNL

CKTS

LR (4MB / S) DT

LR

LR

COMMUNICATION MULTIPLEX

TMN

2 MB/S

PCM

CSNDBT

OCB-283 FUNCTIONAL

DIAGRAM

SMA

SMX



SUBSCRIBER

CCESS

SYSTEM

CONNECTION

ND

CONTROL

OPER TION

ND

M INTEN NCE

CCITT #7

SIGNALLING

NETWORK

TELEPHONE

NETWORK

DATA

NETWORK

VALUE

ADDED NETWORK

O&M

NETWORK

DISK

M GT PEPABX

• SUBSCRIBER

ACCESS SUBSYSTEM

• CONTROL &

CONNECTION

SUBSYSTEM• OPERATION &

MAINTENANCE

SUBSYSTEM

OCB-283 ARCHITECTURE OCB-283 COMPRISES OF FOLLOWING 3

SUBSYSTEMS



Subscriber Access

Subsystem• Subscribers in ocb-283 are connected on digital

subscriber center (CSN)

• CSN can be local or distant

• Local CSN is called CSNL

• Distant CSN is called CSND

• Subscribers can also be connected via a CSED




COMETA

PU

PE

SMT

URM

MCX

CSNL

CKTS

LR (4MB / S) DT

LR

LR


TMN

2 MB/S

PCM

CSNDBT

SMA

SMX

SUBSCRIBER ACCESS

SUBSYSTEM



Control subsystem

• Control subsystem supports all the common

control functions of exchange which

setup & release a call

• Common control functions are :- MR, TR, TX,MQ, GX & PC

• In software form they are called logicalmachines

• Hardware component is called main

control station [SMC]





COMETA

PU

PE

SMT

URM

MCX

CSNL

CKTS

LR (4MB / S) DT

LR

LR

TMN

2 MB/S

PCM

CSNDBT

OCB-283 FUNCTIONAL

DIAGRAM

SMA

SMX

CONTROL

SUBSYSTEM



Connection Subsystem

It comprises of Switching Matrix Station(SMX),Trunk multiplex Station(SMT), Auxiliary EquipmentStation(SMA) & all associative LR links.

It consists of connection equipment forconnecting PCM junctions, auxiliary equipmentfor tones and signaling, switching equipment forperforming digital time switching.




COMETA

PU

PE

SMT

URM

MCX

CSNL

CKTS

LR (4MB / S) DT

LR

LR


TMN

2 MB/S

PCM

CSNDBT

SMA

SMX

CONNECTION

SUBSYSTEM



Operation and

Maintenance Subsystem IN OCB-283 all the operation and maintenance

activities are performed by O&M unit.

This provides access for man machine dialogues

for the human operators to interact andcommand the working of exchange instruments.




COMETA

PU

PE

SMT

URM

MCX

CSNL

CKTS

LR (4MB / S) DT

LR

LR


TMN

2 MB/S

PCM

CSNDBT

OCB-283 FUNCTIONAL

DIAGRAM

SMA

SMX

O & M

SUBSYSTEM



CALL PROCESSING

CKTS

OM

TR MR MQ GX PC

ETA

TX

MAS

MIS

SC SC

SC

SMX

COM

CSNL

CSND

CSNL

VC VC

SC

SMT

PU/PE

SC: Signaling channel

VC: Voice channel



NEW CALL MESSAGE COMES ON SIG.CHANNEL SC TOPU/PE WHICH DETECTS ERRORS

CKTS

OM

TR MR MQ GX PCTX

MAS

MIS

SC SC

SC

SMX

COM

CSNL

CSND

CSNL

VC VC

SC

SMTETA


VC: Voice channel

‘ ’

‘ ’

PU/PE



NEW CALL MESSAGE IS SENT TO MR BY PU/PE.

tr provides subs data to mr.

mq provides address of vc on smx to mr.

CKTS

OM

TR MR MQ GX PCTX

MAS

MIS

SC SC

SC

SMX

COM

CSNL

CSND

CSNL

VC VC

SC

SMTETA


VC: Voice channel

‘ ’

‘ ’

PU/PE



MR ORDERS SMX FOR CONNECTING DIAL TONE TO

CALLING SUBS

CKTS

OM

TR MR MQ GX PCTX

MAS

MIS

SC SC

SC

SMX

COM

CSNL

CSND

CSNL

VC VC

SC

SMTETA


VC: Voice channel

‘ ’

‘ ’

PU/PE



FIRST DIGIT IS RECEIVED VIA VOICE CHANNEL VC IN

ETA

ETA SENDS IT TO MR ON MAS

DIAL TONE IS CUT OFF ON ORDERS OF MR

CKTS

OM

TR MR MQ GX PCTX

MAS

MIS

SC SC

SC

SMX

COM

CSNL

CSND

CSNL

VC VC

SC

SMTETA


VC: Voice channel

‘ ’

‘ ’

PU/PE



ROUTING OF CALL -

MR ORDERS CSN-B TO TEST ‘B’ & GIVE VC FOR ‘B’

CSN-B TESTS ‘B’ AND GIVES RINGING TO ‘B’

SMX GIVES RBT TO ‘A’


VC: Voice channel

‘ ’

‘ ’

CKTS

OM

TR MR MQ GX PC

A B

TX

MAS

MIS

SC SC

SC

SMX

COM

CSNL

CSND

CSNL

VC

SC

SMT

PU/PE



CALLED PARTY B GOES OFF HOOK

CALLED PARTY’S CSN SENDS LOOP CONDITION & VC-

B GIVES INFORMATION TO MR OVER SC VIA PU/PE

RINGING CURRENT & RBT ARE STOPPED

‘ ’

‘ ’

CKTS

OM

TR MR MQ GX PCTX

MAS

MIS

SC SC

SC

SMX

COM

CSNL

CSND

CSNL

VC-A

SC

SMT


VC: Voice channel

PU/PE

VC-B



‘ ’

‘

CKTS

OM

TR MR MQ GX PCTX

MAS

MIS

SC SC

SC

SMX

COM

CSNL

CSND

CSNL

VC-A

RGF

SC

STM

SC: Signaling channelVC: Voice channel

PU/PE

VC-B

TWO UNIDIRECTIONAL CONNECTIONS ARE

ESTABLISHED IN SMX ON ORDER OF MR VIA GX

‘A’ & ‘ B ‘ CAN NOW CONVERSE

CHARGING IS STARTED BY TX - MR RELEASED



Happy talking!!

OCB-283

EXCH

AND YOUR

METER

IS RUNNING

HERE!!!



Facilities Provided by

OCB-283 A line can be made only incoming or outgoing.

Immediate hot line

Delayed hot line

Abbreviated Dialing

Call Forwarding

Call Waiting

Conference call



THANK YOU!

mtnl summer training presentation

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