Bharat Sanchar Nigam Limited (BSNL) is India's largest telecommunications company that provides various telecom services across India. It operates through telephone exchanges that house switching equipment to facilitate call connections. The exchanges have different components like the main distribution frame for fault removal, power plants for electricity supply, and switch rooms containing cabinets for routing calls. BSNL also offers broadband internet through technologies like ADSL that provide high-speed connectivity to customers via the existing telephone network infrastructure.

1. PROJECT REPORTonOnBSNL

2. INTRODUCTIONSTARTED in October 2000, with the vision of becoming the largest telecom service provider in Asia, Bharat Sanchar Nigam Limited is the world’s seventh largest telecommunications company. It provides a comprehensive range of services in India, which include wireline connections, CDMA (code division multiple access) mobile, GSM (global system for mobile communications) lines, Internet, broadband, MPLS-VPN (multi protocol label switching-virtual private network), VSAT (very small aperture terminal) and VoIP (voice over Internet protocol). Within this short span of time, it has also become one of the largest public sector companies in India.

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

4. 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.

5. 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> EWSDC-DOT:-Work on telecom technology products and services. Provide solutions for current and future requirements of telecommunication and converged networks including those required for rural application.Provide market orientation to R & D activities and sustain C-DOT as center of excellence.OCB:-It is a digital switching system.The system supports all the existing signaling systemThe system has ‘auto recovery’ feature. When a serious fault occur in control unit, it gives a message to SMM (operation & maintenance unit).

6. EWSD:- The EWSD Digital Switching Systems offer a wide range of telephony features and supplementary services. Further capabilities can be developed to meet specific customer needs.

7. EXCHANGE LAYOUTSwitch Room

8. Operations and Maintenance (OMC) Room

9. Input Output processor (IOP) Room

10. Power Plant Room

11. Battery Room

12. Main Distribution Frame (MDF) RoomMDF

13. Power plant

14. Switching RoomThere are three main components of exchange:

15. MAIN DISTRIBUTION FRAME(MDF):-Local cable contact at MDF .

16. All types of cables out to the door contact connection at MDF .

17. The primary function of MDF is to remove fault. It is also known as Fault Remove Section.

18. The telephone numbers are also disconnected in the MDF because of some specific reason.Main Distribution Frame (M.D.F)

19. ORGANIZATION OF MDF:- Vertical side

20. Horizontal sideVertical 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 tags1 tag = 4 core1 core = 4 bunch1 bunch = 2 lineN.E:-The word NE stands for the ‘NUMBER OF EQUIPMENT’. It is used for testing numberWedge:-Wedge is used as a device for checking the ring. Wedge is placed in jack strips, which is connected to telephone for checking.

21. 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.

22. POWER PLANTAs 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 is the input.The main source of this exchange is AC supply.The main part of power room are:-1. Batteries2. UPS (Uninterrupted Power Supply) 3. Charging - Discharging Unit4. Inverter and Converter Unit:

23. Switch Room:-Switch room consists of BM and CM cabinets mounted in standard switch.