The document summarizes an industrial visit to BSNL in Shillong. It provides details about the various sections visited including the power plant room, battery room, IP TAX room, networking room, OCB TAX room, and main distribution frame room. It describes the key components and functions of each section. The document concludes that the visit provided valuable practical exposure to the students about the working of a telephone exchange and various BSNL technologies like GSM, GPRS, WiMAX, and optical fiber transmission. It helped enhance the students' understanding beyond classroom teaching. Recommendations provided focus on improving telecom connectivity and services in India's North Eastern Region.

1. 2014
Sombaran Gupta
BSNL
11/15/2014
Industrial Visit

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Table of contents
Acknowledgement
Introduction
Methodology
Discussion
Recommendations
Conclusion

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Acknowledgement
We are thankful to the Pro- Vice Chancellor, Mr. Mukesh Saxena for organizing
such a great education tour. Our sincere appreciation is extended to the instructors
Dr. D. Bhattacharya, Mr. F. Rynjah, Mr. P. Maitty and Ms. P. Bora for
instructing us during the trip.
The trip was a great experience which gave a real exposure to the industry. It was
highly beneficial for all the students as it explained the theoretical and practical
concepts both.
We are also thankful all the instructors at the Transmission and Broadband sections
who provided the detailed explanations oftelecom processesand operations and help
us preparing short notes during the trip. They also led us to the background and
requirements of Telecom station.

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Introduction
Started in 2000, with the vision of becoming the largest telecom service provider in
Asia, Bharat Sanchar Nigam Limited is the world seventh largest
telecommunications company. It provides comprehensive range ofservices in India,
which include wire line connection, CDMA (codedivision multiple access)mobile,
GSM (global system for mobile communications) line, internet, broadband, MPLS-
VPN (multiple protocollabel switching- virtual private network), VSAT (very small
aperture terminal) and VoIP (voice over internet protocol). Within this short span of
time, it has become one of the largest public sectors in India.
Components in exchange
The switching center, which houses the terminating and switching equipment is
called telephone exchange. And the equipment which effects the interconnection of
telephones is known as switching equipment.

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About the exchange
All telephone subscribers are served by automatic exchanges and automatic
exchange uses a pair of computers.
One pair, for running the program that provides services.
Second pair, for monitoring the operations of the first, ready to take over in a few
seconds in the event of equipment failure.
Exchange layout
Power plant room
Battery room
Main distribution frame (MDF)
Switch room
Operation and maintenance room (OMC)
Input output processor room (IOP)
There are three main components of exchange:
 MDF room
 Power plant room
 Switching room
Power plant room is the heart of BSNL.

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Power plant
As we all know that, the power is the main source of any organization. That is the
first requirement of any organization is the input. The main source of this exchange
is the AC supply. This act as the feeding point of power all other sections. Regulated
power supply is used that help in switching mode.

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The power plant consists of a very important machine which is SMPS (switched
mode power supply). The AC power is fed to the LPU (lightning protecting unit)
which protect AC power from lightning. After this AC power is fed to the SMPS.
In that power plant room there are two SMPS.
 Old SMPS (3 module)
 New SMPS (6 module)
This AC power in the distribution box is converted into DC power are fed along the
busbars to the other components. The SMPS does two things:
 AC supply charges the UPS
 Converts AC to DC power supply
The roomtemperature ofthe powerplant must be maintained byexhaust fans, proper
ventilation so that the module works properly.
Rating of SMPS and UPS
 N * 100 A
 1 KV
Manufacturing company for SMPS
 Exicom power plant
 ITI
The other main components of power plant room are:
 Batteries
 UPS
 Charging and discharging unit
 Inverter and control unit

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Battery room
There are two sets ofbatteries in that room, one for normal use and other for backup
in case the first battery fails. Minimum voltage required (DC) is 48V.
1 battery for 24V each supply a minimum of 2V. That is output voltage is 48V.
Fuse is required for charging the batteries and hence the supply is passed through
fuse. Temperature sensors is used for sensing the room temperature to protect any
chemical reaction inside the batteries.
Rating for batteries
 Local 5000A required 1300A
 IP TAX 600A required 60A

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IP TAX room
Above figure shows section of DC distribution box which takes power from the
power plant room.

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This room works for / processesforthose calls which are not local that is it is out of
the state. Calls are transferred to this sections which are trunk automatic exchange
(TAX).
Networking room
BSNL offers Internet service with a speed range of 2 Mbps to 8 Mbps across 3,200
towns and cities. Out of the 612 district headquarters in the country, 585 have
broadband connectivity.

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What is broadband?
An ‘always-on’ data connection that is able to supportinteractive services including
Internet access and has the capability of the minimum download speed of 256 kbps
to an individual subscriber from the Point of Presence(POP)ofthe service provider.
Broadband Services Applications
 High Speed Internet Access Always-On(Talk & Surf Simultaneously on same
Telephone Line )
 LAN Access (Teleworking): Virtual Private Network (VPN) for Corporate
Customers
 Broadcast TV/Video On Demand
 Video Conferencing, Gaming & Home Shopping-Interactive Services
 Distance Learning & Tele Medicine

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OCB TAX room
 It is a digital switching system.
 The system supports all the existing signaling system
 The system has ‘auto recovery’ feature. When a serious fault occurin control
unit, it gives a message to SMM (operation & maintenance unit).

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Main distribution frame room
 Local cable contact at MDF.
 All types of cables out to the door contact connection at MDF .
 The primary function of MDF is to remove fault. It is also known as Fault
Remove Section.
 The telephone numbers are also disconnected in the MDF because of some
specific reason.
Organization of 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

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• 1 tag = 4 core
• 1 core = 4 bunch
• 1 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.

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Recommendations
According to the telecom regulatory authority of India the North Eastern Region
(NER) of India comprises the States of Arunachal Pradesh, Assam, Manipur,
Meghalaya, Mizoram, Nagaland, Sikkim and Tripura. They form part of the East
Himalayan region. These eight States cover an area of 2, 62,189 sq. km, about 8%
of the country’s total geographical area. The region has a long international
boundary. About 96% of the boundary of this region has China and Bhutan in the
north, Myanmar in the east, Nepal in the west and Bangladesh in the southand west.
Many of the States in the region like Arunachal Pradesh, Meghalaya, Mizoram and
Nagaland, have large tribal populations. The region is characterized by an extremely
tough terrain with poor infrastructure like rail, roads, electricity and telecom.
Connectivity is the most important key to development of a region; be it road, rail,
waterway, air, power or telecom. Connectivity ensures that an otherwise distant
region is part and parcel of the mainland. It helps in overall economic development
and social integration ofthe region. Robusttelecom and broadband connectivity and
provision of quality telecom services is an avowed national priority. Hence,
delivering such quality services and connectivity to the NER is an integral
Component of realizing the national objective.
The recommendations are grounded in three main constituents:
 The Gap analysis
 The State-wise suggested telecom plans
 The estimation of investment required for implementation of the Suggested
overall plan.

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Conclusion
Engineering student will have to serve in the public and private sectorindustries and
workshop based training and teaching in classroomhas its own limitation. The lack
of expo sure to real life, material express and functioning of industrial organization
is the measure hindrance in the student employment.
In the open economy era of fast modernization and tough competition, technical
industries should procedure pass out as near to job function as possible? Practical
training is one of the major steps in this direction. I attended the industrial visit
BSNL, Shillong which is one of the best known communication service provider
companies of India. The training helps me in gaining in depth knowledge of the
working of telephone exchange, various technologies of BSNL–GSM, GPRS,
WIMAX, Wi-Fi, MLLN and optical fiber transmission.
In the end, I hereby conclude that I have successfully completed my industrial
training on the above topics.
References
 www.bsnl.co.in
 www.newbsnl.co.in

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