Supervised by-Ms.Heena singhMr.Puneet kaliaMr.lokesh lodha

Submitted by-Nalini anandV semester5 EC-53

SUMMER TRAINING REPORT Held At BSNL

1. IntroductIon2. networkIng3. About the exchAnge4. MAIn sectIon of exchAnge 4.1 Mdf 4.2 power plAnt 4.3 swItch rooM5. ocb6. gsM7. gsM ArchItecture8. cAll setup9. geogrAphIcAl AreA of gsM10. wll11. servIce provIded by wll12. cdMA13. sAlIent feAtures of cdMA

• INDIA’S first telecom company.

• Became corporation in. 2000

• World’s 7TH and INDIA’S no. 1

• Line capacity of 47.5 million

• BSNL providing a number of different Telecom networks.• Wireless networks - Transfer of information

without use of wires.• Two main acess scheme - CDMA and

TDMA(GSM)• Wireline networks – A number of services like

basic telephone, internet services (BROADBAND, DIAL-UP) ETC.

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:

1. C-DOT2. OCB

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

It is a large iron frame, divided into two parts.

1) Exchange side: exchange side is connect with the switch room.

2) Line side: line side is connected with the subscribers.

The MDF is connected with the switch room with the help of cables have different colour codes. The colour codes consist of:1)Main colour: Blue, Orange, Green, Brown, Grey 2)Assistant colour:White, Red, Yellow, Black

FAULTS THAT MAY OCCUR

This is one of the important section of the exchange which control the whole exchange runs.The power can be provided using one of the following methods. Direct mains supply which is converted into dc with the help of rectifiers. Power generator Battery

1. At present, Switching system is based on the principle of stored program control(SPC).2. Program related to call processing divided in different stages of system & are stored in its RAM/ROM.3. Processer used in control unit’s handle or process the call is to establish a connection b/w incoming and outgoing edges of a switch.

It’s the type of exchange which is being used in BSNL

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).

• In 1982,European countries created an organization called “GROUPE SPECIALE MOBILE” (GSM)

• In1988,GSM was included in ETSI and by 1991 first GSM network launched

• Combination of three major subsystem• Frequency bands-

Mobile To Cell – 890 - 915 MHz (UPLINK) Cell TO Mobile – 935 - 960 MHz (DOWNLINK)

HLR

PHONEBSS

BSS

MSC

VLR

GMSC

BSS

Public Network

CALL SETUP

1. WLL means to serve the subscribers' at home and offices without using wires.

2. Wireless based local communication network.

3.Provides voice and non voice services.

4. Services in rural and urban areas.

1.BASIC SERVICES: voice, fax, low speed data

2.SUPPLIMENTRY SERVICES:Call forwardingCall waiting and call barringAutomatic call backConference calling

3.SERVICE QUALITY:Voice qualityNetwork availability

1. These techniques are referred to as Spread Spectrum Systems.

2. Multiple access capabilities, they are useful in combating jamming, and are for this reason principally used in military systems.

3. CDMA channel in the trans and receive direction is a FDD (Frequency Division Duplexing) channel.

1.Frequency Operation : 824-849 Mhz and 869-894 Mhz

2.Duplexing method: Frequency Division Duplexing (FDD)

3.Acess Channel Per Carrier: Maximum 61 Channel

4.RF spacing: 1.25 Mhz

5.Coverage: 5 Km with hand held telephones , 20 Km with fixed units.

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