Submitted by:-Vaibhav Bhootna(EC09121)

Submitted to:-Ms. Garima Mathur(HOD,ECE)

Jaipur Engineering College, Kukas

A presentation on summer training

taken atAT

bsnl

Contents

Company Profile Introduction Services Provided Exchange MDF OCB GSM Conclusion

Company Profile

Type: State-Owned Enterprise

Head Quarter's New Delhi

Key People: Mr. R K Upadhyay (Chairman & MD)

Established: Oct 2000

Owner: Govt. Of India

INTRODUCTIONToday, 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 cities

Services Provided

Universal Telecom ServicesCellular Mobile Telephone ServicesWLL-CDMA Telecom ServicesInternetIntelligent Network3GIPTVVVoIPWiMax (4th Gen Wireless Broadband)

Telephone Exchange…

Equipment which effects interconnection of telephones is known as switching equipment. The switching centre, which houses the terminating and switching equipment is called telephone exchange.

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

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 

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

Main Distribution Frame is a signal distribution frame or a cable rack used in telephony to interconnect and manage telecommunication between itself and any number of intermediate distribution frame and cabling from the telephone network it supports

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 line

N.E.:-The word NE stands for the ‘NUMBER OF EQUIPMENT’.It is used for testing number .

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.

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 .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).

Making a telephone call

Use of -48v DC Supply DC voltage is used because it doesn’t produce any

noise on the line.

48v is efficient to transmit over a long distance and safe for Telecom Technician and service personnel.

Negative Voltage is used to reduce the corrosion from electro-chemical reactions occurring on a wet telephone wire.

GSM

GLOBAL SYSTEM FOR MOBILE COMMUNICATION

History

- Torleiv Maseng is regarded as the father of the GSM Technology.- 1989, GSM responsibility was transferred to the European Telecommunications Standards Institute (ETSI)- first GSM network was launched in 1991 by Radiolinja in Finland with joint technical infrastructure maintenance from Ericsson.

What is GSM ? Global System for Mobile Communication

GSM is an ETSI standard for 2G Pan-European digital cellular with international roaming

GSM frequencies• 2G GSM networks operate in the 900 MHz or 1800

MHz bands.

• GSM-900 uses 890–915 MHz to send information from the mobile station to the base station (uplink)

• 935–960 MHz for the other direction (downlink),

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 at

least 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.

NETWORK STRUCTURE

Basic Terms :

Mobile Equipment (ME)Subscriber Identity Module (SIM) Base Station controller (BSC)Base Station Subsystem (BSS) Mobile services Switching Center (MSC) Home Location Register (HLR)Authentication Centre (AuC)Equipment Identity Register (EIR) Visitor Location Register (VLR) Public Switch Telephone Network (PSTN)

Mobile Station (MS) & Subscriber Identity Module (SIM)

• MS refers to the physical phone itself.• uniquely identified by the

International Mobile Equipment Identity (IMEI) number.• Sim is small smart card that

is inserted into the phone and carries information specific to the subscriber

Base Transceiver Station (BTS)

• carry out radio communications between the network and the MS

• handles speech encoding, encryption, multiplexing (TDMA), and modulation/demodulation

BASE STATION CONTROLLER

• allocation of radio channels

• frequency administration

• power and signal measurements from the MS,

• handovers from one BTS to another

 

MOBILE SWITCHING CENTER(MSC)

• call routing, call setup, and basic switching functions

• inter-BSC handoffs as well as coordinates with other MSC's for inter-MSC handoffs.

Gateway Mobile Switching Centre (GMSC)

• gateway between two networks

• switch to the Public Switched Telephone Network (PSTN).

HLR & VLR

• HLR maintains subscriber- specific information such as the MSISDN, IMSI, current location

of the MS, roaming restrictions,

• VLR is a database that contains

a subset of the information located on the HLR

Equipment Identity Register (EIR) & Authentication Centre (Auc)

• EIR is a database that keeps tracks of handsets on the network using the IMEI

• handles the authentication and encryption tasks for the network =

MSISDN & IMSI MSISDN is Subscriber Telephone number IMSI (International Mobile Subscriber Identity)

MSISDN is a number uniquely identifying a subscription in a GSM or UMTS network.

The MSISDN and IMSI are two important numbers used for identifying a mobile subscriber

IMSI is used as key in HLR IMSI is uniquely associated to a SIM

Identification of number

ConclusionDuring this summer training period at RTTC Jaipur , I come to know about the various telecommunication equipment and technologies used earlier , or which are currently in use such as GSM 3G & CDMA, switching systems of OCB & CDOT and data communication systems with Internet nodes , Wi-Fi equipment, IP VPN.

Basically I have discussed the GSM and the telephone exchange to give an overview to understand the telecommunication system.

Thank You

Any Queries ???

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