1. Connected cars that are able to optimize their own operation and connect to the outside world to enhance the driving experience. 2. Cheaper 4K monitors and TVs that offer much sharper images at higher resolutions. 3. The growing field of digital health that uses wireless devices and sensors to help people better track and manage their health.

2. Prof. Dr. Malay Gangopadhyay
EDITOR, ELECTROVISION
This is a time of great changes. In education too we see fast changes. The
student today is an individual, is a real person with feelings of self-respect,
sensitivity, responsibility and compassion. We need to recognize, appreciate,
applaud and foster the fine blend of sensibilities in a student – and thus this
IEM-Electrovision is to be viewed as a launch pad for the students’ creative
urges to blossom naturally. As the saying goes, mind like parachute works
best when opened. This humble initiative is to set the budding technocrats
free allowing them to roam freely to explore and experience technology.
The institute attains its eminence in the first place through the achievement
of students’. I believe IEM-Electrovision would spur higher growth and
enterprise in students’. I sincerely express my gratitude and thank the
Director, Prof. Satyajit Chakrabarti, Principal, Prof. Dr. A.K.Nayak , the entire
editorial board, students and teachers who have been of immense help in
breathing life into these pages. All the Best!!!!!

3. Prof. Dr. G.S. TAKI Prof. GAUTAM GHOSH Prof.
INDRANIL BASU
Prof.
PARTHA SARATHI
PAUL
Prof.
ARINDAM
CHAKRABORTY
Prof.
RATNA
CHAKRABARTY
Prof.
INDRANI
BHATTACHARYA
Prof.
MILI SARKAR
Prof.
RAJIB GHOSH
Prof.
ARUNAVA
MUKHOPADHYAY
Prof.
TUHIN UTSAB PAUL
Prof.
SRIJITA
CHAKRABORTY
Prof.
DEBARSI
CHAKRABORTY
Prof.
DEBADYOTI GHOSH
Prof.
MOLOY NARAYAN
DAS
Prof. Dr. MALAY
GANGOPADHYAY
FACULTY EDITORIAL
AND
DESIGN TEAM

4. STUDENT EDITORIAL
AND
DESIGN TEAM
RAJARSHI
DAS
AGOMONI
SARKAR
AISHWARIYA
CHAKRABARTY
SAGAR
DEV MAITY
PALLABI
SINHA
NILOY
SAHA
ECE 4th YEAR
Institute of Engineering & Management (IEM) opens up the doors of young minds
who dare to dream. It encourages the spirit of free enquiry and imagination. Here
dreams take shape. The Institute tries to indicate the sense of human values and
discipline to make students respectful towards human beings, realise and
demonstrate their best potential and be winners in life. The Institute is affiliated to
the West Bengal University of Technology (WBUT). B.Tech., M.Tech., MBA courses
are approved by AICTE, Govt. of INDIA.
The Electronics and Communications Engineering (ECE) Department of IEM
emphasizes technical skills that can be used to help design, develop, install, test
and maintain communications systems. Students may begin to pursue career
opportunities in a variety of entry-level positions, such as electronics engineering
technologist, electronics engineering assistant, engineering sales/service
representative, computer systems technologist, technical consultant,
telecommunications technician, communication systems installer, field service
representative, engineering technician or research technician. Our top domain
recruiters are Ericsson, Vodafone, Bharti Airtel, Sankalp Semiconductor. The
students may also sit for placements in the IT sector companies.
High ranking students from WBJEE and AIEEE take up ECE at IEM because we strive
to be an exciting place to learn and work, where no goal is too ambitious to strive
for, where nothing is too sacred to laugh at, and where everybody's ideas count.

5. contents Dept of Electronics & Communication | Institute of Engineering & Management
ELECTROVISION 2015
Hi, I’m Cortana.
C O R T A N A
your personal assistant
c o n n E C t
alumni speaks
I N T E R N S H I P S
gaining work-experience in college
Did You Know??!!
Interesting Facts
# Trending
Technologies in trend
Smart Glove
Innovation, for the visually impaired
Global Positioning System
An overview
Photo Gallery
Memories preserved in frames
SMS based Security System &
Control of Household Gadgets
A project report
Free Li-Fi Available Here!
Visible light communication
Steganography
The dark cousin of Cryptography
Bluetooth-Controlled Switchless
Home
A project report
Optimistic View of Efficient &
Automated Traffic Control System
A report
The Fourth Protocol
4th gen internet technology – the mobile race to
innovation
5000 A.D.
A sci-fi short story
Building Innovation from Ideas
Hands-On
DIY: Make PCBs at Home
Using Toner Transfer in 9 Easy Steps
Exercise your Brains
Quiz
Crossword
Content Editor : Agomoni Sarkar | Graphics & Design : Rajarshi Das

6. Did You Know ??!!
Cortana, do you know the history of voice
command? Back in the 1870s, Thomas
Edison invented the phonograph, and
Alexander Graham Bell and two associates
worked on a “Dictaphone”.
When it comes to Massive Multiplayer Online
Role-Playing Games (MMORPGS), World of
Warcraft is top dog. The game has more than 10
million active players and has generated billions of
dollars in revenue for owner Activision Blizzard
since it launched in late 2004.
Emoticons were reportedly first used on
September 19, 1982, by Scott Fahlman, a computer
scientist at Carnegie Mellon University. He created a
happy face and a sad face with a colon, a hyphen and
parentheses.
When it comes to Massive Multiplayer Online
Role-Playing Games (MMORPGS), World of
Warcraft is top dog. The game has more than 10
million active players and has generated billions of
dollars in revenue for owner Activision Blizzard
since it launched in late 2004.
The man known as the Father of Information
Theory, Claude Shannon, invented the digital
circuit – the foundation of the magic that provides
us all access to the Internet today - during his
master’s degree program, when he was just 21 years
old.
The first mouse was invented
by Douglas Engelbart in 1963;
it consisted of a hard wooden
shell and two clunky metal
wheels.
It has been 41 years
since the world’s
first mobile phone
call successfully
took place.
First GPS satellite
was launched in
1978, and the full
constellation of 24
became operational
in 1995.
Bluetooth was
named after a
Danish king who
united disparate
territories.
6

7. Morton Heilig, the “Father of Virtual
reality,” patented the Sensorama
Stimulator on Aug. 28, 1962. This
evolved into augmented reality.
There are 6.8 billion people
on the planet and 4 billion of
them use a mobile phone.
Only 3.5 billion of them use a
toothbrush.
Spam generates 33bn KWt-hours of
energy every year, enough to power
2.4 million homes, producing 17
million tons of CO2.
Flickr hosts some 5 billion
photographs, Facebook
hosts more than 15
billion.
The Motorola DynaTAC 8000X was the first cell
phone sold in the US; launched on April 11, 1984, it
was designed by Rudy Krolopp and weighed 2
pounds.
If MySpace were a country it
would be the 5th-largest in
the world (between
Indonesia and Brazil).
The first GPS satellite was
launched in 1978, and the
full constellation of 24
became operational in
1995.
QWERTY Keyboards were designed by
Christopher Sholes, who invented the
typewriter in 1868. However, alternative
keyboard layouts, like the Dvorak and the
Capewell, abound.
The average 21 year old has spent 5,000
hours playing video games, sent 250,000
emails, instant messages, and text messages,
and has spent 10,000 hours on a mobile
phone alone.
7

8. Freud’s ideas of how technology may have
made life harder and more difficult to find
happiness can be viewed in the way that man
has not gained the capacity to fully utilize the
technology available. If man had advanced as
quickly as the technology and civilizations did,
maybe he would be uncontestably happier
than in primitive times. With all the new
technology appearing quicker than the
majority can learn to use it, people become
overwhelmed by all the new ideas and thus can
feel unhappy despite having the opportunity to
reach a greater level of happiness if the
technology were used.
Here’s a list of the hottest trends in the market
today which could make us extremely happy –
if only we could utilise it all to its full potential.
Connected Cars
Today’s car has the computing power of 20
personal computers, features about 100
million lines of programming code, and
processes up to 25 gigabytes of data an hour.
Yet while automotive digital technology has
traditionally focused on optimizing the
vehicle’s internal functions, attention is now
turning to developing the car’s ability to
connect with the outside world and enhance
the in-car experience. This is the connected
car—a vehicle able to optimize its own
operation and maintenance as well as the
convenience and comfort of passengers using
on-board sensors and Internet connectivity.
While the total cost of ownership of vehicles
will remain stable for consumers, the dramatic
increase in vehicle connectivity will increase
the value of the global market for connectivity
components and services to €170 billion by
2020 from just €30 billion today (McKinsey
Insights 2014).
While technological advances have driven the
automotive sector for decades, this dramatic
acceleration as a result of connectivity has the
potential to significantly alter the competitive
landscape. Companies from the software and
telecommunications sectors are already
entering the automotive market, and a new
McKinsey report finds that original-
equipment manufacturers need to act now to
secure control over critical industry sectors.
Cheaper 4K Monitors and TVs
A FullHD display with a resolution of
1920x1080 has about 2.1 megapixels. A typical
4K PC display, however, has a native
resolution of 3840x2160, or roughly 8.3
megapixels—that’s double the resolution and
approximately four times as many pixels. All
other things being equal, 4K PC displays are
# Trending ELECTROVISION
Editorial Team
8

9. 9
capable of producing much sharper on-screen
images.
The higher resolution also affords users the
ability to view or edit 8MP (or smaller) photos
and 4K content at native resolutions, without
scaling. That’s not a huge deal for most PC
users, but for creative professionals hell-bent
on accuracy, working with unscaled images is
an exciting prospect.
For the most part, powering a 4K display won’t
be an issue for everyday computing tasks like
browsing the web or working in office-type
applications, even with today’s integrated
graphics solutions.
Digital Health
Digital health is the convergence of the digital
and genetics revolutions with health,
healthcare, living, and society. The benefits of
digital health include the empowerment of
consumers to better track, manage, and
improve their own and their family’s health. In
healthcare, digital technology is also helping
to reduce inefficiencies in delivery, improve
access, reduce costs, increase quality, and
make medicine more personalized and
precise. Venture investment in digital health
in 2014 reached $4.1 billion, a 125% increase
year-over-year.
Remarkably, aggregate investing in digital
health surpassed that in traditional healthcare
and medical devices for the same time period.
The essential elements of the digital health
revolution include wireless devices, hardware
sensors and software sensing technologies,
microprocessors and integrated circuits, the
Internet, social networking, mobile/cellular
networks and body area networks, Health IT,
genomics, and personal genetic information.
There are already dozens of health-related
products like Nike’s FuelBand, Jawbone’s UP,
Fitbit, Misfit’s Shine and others, all of which
can be used as part of a personal health-
monitoring system. iHealth has a digitally-
connected glucose testing kit, and the
company’s digital blood pressure cuff uses the
iPhone for controlling the cuff and delivering
data to the user.
The lexicon of Digital Health is extensive and
includes all or elements of mHealth (aka
mobile health), Wireless Health, Health 2.0,
eHealth, e-Patient(s), Healthcare IT / Health
IT (information technology), Big Data, Health
Data, Cloud Computing, Quantified Self,
Wearable Computing, Gamification,
Telehealth / Telemedicine, Precision Medicine
and Personalized Medicine, plus Connected
Health.

10. 10
Curved TVs
One of the biggest marketing hooks upon
which curved TV manufacturers like LG and
Samsung are hanging their hats is the idea that
curved TVs provide better a better viewing
experience, and there is some scientific
evidence to back up the claim.
Oshin Vartanian and colleagues at the
University of Toronto's Department of
Psychology have been working in the field of
neuro-aesthetics. This is the study of what
neurological factors play a role in the things we
find pleasing to the eye, or not. Research by
Vartanian and his team suggests that we
naturally find curved objects more pleasing
than those with straight edges. Dr. Raymond
M. Soneira explains that the concave shape
reduces the number of reflections on a screen
by eliminating certain angles from which they
can be created. He also points out that the
curved shape keeps the screen at a more
uniform distance from the viewer's eyes when
they are sitting centrally. This reduces the
slight visual geometric distortion caused by
the fact that the sides of the TV are further
away from the viewer than the centre when
looking at a flat screen.
This more uniform distance from the edges
and the centre of the screen to the viewer's
eyes is something to which Samsung, amongst
others, has argued there are other benefits. By
bringing forward the sides of the screen, a
curve effectively increases size of a TV as
perceived by the viewer. This is because it
subsequently fills more of the individual's field
of view.
So it would seem that along with their
futuristic looks, there are some tangible
benefits to curved TVs. Whether or not these
justify the significant price hike over their flat
counterparts is another matter entirely.
3D Printers
With each passing year, the 3D printing
industry grows by leaps and bounds. Food safe
PLA is now the norm, with dissolvable and
other exotic filaments becoming more
mainstream. New filaments are making it
possible to print objects that were not possible
before. New CAD software is popping up like
dandelions, with each iteration giving novice
users a friendly and more intuitive interface to
design 3D models. As time marches on, and we
look into its future, a vision of the 3D printing
world is evident – it’s only going to get bigger.
Imagine a future where a 3D printer is as
common as an ink jet printer in homes all
across the world. A future where you could
buy filament from the supermarket down the
street, and pick up a new printer from any

11. 11
hardware store. A future where dishwashers,
refrigerators and bicycles come with .stl files
that allow you to print upgrades or spare parts.
A future where companies compete to give the
market easy-to-use printers at the cheapest
price.
Is this future possible? Not until the
technology changes. It’s too expensive, and
that’s the problem you’re going to solve. How
can you make a 3D printer cheaper? A cheap
printer could change the game and make our
future a reality.
The Smart Home
When you're not home, nagging little doubts
can start to crowd your mind. Did I turn the
coffee maker off? Did I set the security alarm?
Are the kids doing their homework or
watching television?
With a smart home, you could quiet all of these
worries with a quick glance at your
smartphone or tablet. You could connect the
devices and appliances in your home so they
can communicate with each other and with
you. Any device in your home that uses
electricity can be put on your home network
and at your command. Whether you give that
command by voice, remote control, tablet or
smartphone, the home reacts.
Most applications relate to lighting, home
security, home theatre and entertainment, and
thermostat regulation.
The idea of a smart home might make you
think of George Jetson and his futuristic abode
or maybe Bill Gates, who spent more than
$100 million building his smart. Once a draw
for the tech-savvy or the wealthy, smart homes
and home automation are becoming more
common.
What used to be a quirky industry that
churned out hard-to-use and frilly products is
finally maturing into a full-blown consumer
trend. Instead of start-up companies, more
established tech organizations are launching
new smart home products. Sales of
automation systems could grow to around
$9.5 billion by 2015. By 2017, that number
could balloon to $44 billion.
Wearables
Wearable technology is related to both the
field of ubiquitous computing and the history
and development of wearable computers.
With ubiquitous computing, wearable
technology share the vision of interweaving
technology into the everyday life, of making
technology pervasive and interaction friction
less. Through the history and development of
wearable computing, this vision has been both
contrasted and affirmed. Affirmed through the
multiple projects directed at either enhancing
or extending functionality of clothing, and as
contrast, most notably through Steve Mann's
concept of ‘sousveillance’. The history of

12. 12
wearable technology is influenced by both of
these responses to the vision of ubiquitous
computing.
On April 16, 2013, Mountain View Corporation
Google allowed for those that pre-ordered its
wearable glasses at the 2012 Google I/O
conference to pick up the device.
This day marked the official launch of Google
Glass, a device that brings rich text and
notifications as well as other information
straight to your eyes.
The device also has a 5 MP camera and records
720p. Its various functions are activated via
voice command. The company also launched
the Google Glass companion app, MyGlass,
the day before the official launch on April 15.
The New York Times's Google Glass App is the
first third-party Glass App and it reads articles
and news's summaries. It is also the first
media app for Google Glass.
“The difference between stupidity and genius is that genius has its limits.” - Albert Einstein

13. In the recent era, blindness and poor vision is
a major setback to mankind. Blindness has
been recognized as an important public health
problem in India, a country that is now home
to a billion inhabitants.
According to a study conducted by Times of
India, 285 million people are visually
impaired and 37 million are blind worldwide
and India is the home to largest number of
blind in the world. Of the 37 million people,
over 15 million are from India. What's worse,
75% of these are cases of avoidable blindness,
thanks to the country's acute shortage of
optometrists and donated eyes for the
treatment of corneal blindness. While India
needs 40,000 optometrists, it has only
8,000. On the other hand, while India needs
2.5 lakh donated eyes every year, the country's
109 eye banks (five in Delhi) manage to collect
a maximum of just 25,000 eyes, 30% of which
can't be used. A lot of people get affected by
ophthalmological diseases irrespective of the
ages. The available supporting sticks are not
able to provide them proper guidance and
other recent equipment made for the blinds in
the market are very expensive. It’s time to cut
down the expense and extend our hands
towards them in a more efficient and cost-
effective way. This SMART GLOVE will not
only serve them, but will also be their sole
guide and friend.
We used an ULTRASONIC SENSOR, to
calculate the distance of an object in front of
the blind person, an ALARM UNIT, as
medium by which the user is supposed to be
alert for the danger, a POWER SUPPLY and
a microcontroller ARDUINO UNO.
Schematic Diagram
Working Procedure
1. All the necessary connections of the
circuit are done and the power supply is
given with the help of portable
rechargeable battery.
2. The hand is supported by a supporter so
that the hand does not ache.
3. The Ultrasonic sensor which is located on
the wrist (below the palm) will be used to
calibrate and measure the average
distance of the ground from the hand i.e.
Smart Glove Aishik Konwer Souvick Saha
Souvik Chakraborty Tamoghna Saha
Sumilak Chaudhury
B.Tech - 2017
13

14. 14
in one way to measure the height of the
person which is different for different
person.
4. After measuring the average distance, the
sensors will start to operate and take
readings. If there will be any obstacle
ahead, then the buzzer will be activated,
warning the blind man about it. The
closer the object comes, the more
frequent will the buzzer sound.
5. Vibrators are attached to the upper and
lower part of a hand. If upper motor
vibrates, then it will indicate presence of
up-staircase. If lower motor vibrates,
then it will indicate presence of down-
staircase. In order to identify how high or
deep is the each step of stair-case, both
for up and down, the device is coded in
such a way that the vibrators will vibrate
in different magnitude. The higher or
deeper the step, the more will be the
magnitude of the vibration. When a
manhole will appear, the vibration will be
highest, alerting the blind man that it’s a
manhole and not a down-staircase.
Applications & Features
When a blind man wears this glove, then it
will help in making right or left turns when
necessary, getting down or walking up a
staircase independently and detection of any
obstacles present in the way of the blind man
like lamp post, stationary car, walls, fence, etc.
It is a non-contact type electronic and stand-
alone probe.
It provides a proper output in a smart way
through vibrators and buzzer so that the user
does not need to panic about his/her dangers
on its way. As the ultrasonic sensor is fitted on
the wrist, there won’t be any water contact
during the rainy season. They are very cheap
but readily available highly efficient sensors.
Future Scope
1. We can use GPS Tracker System to get
the exact location of where the blind
person is standing right at that point
of time, when he pushes an
“Emergency Push Button” and
thereby sending an alert message to
the number registered in the GPS
Module along with the location co-
ordinate, providing a better way of
seeking help from the one who cares
about them.
2. We can use a voice module APR33A3
instead of vibrators which can store
voice record like “Staircase Up”,
“Staircase Down”, “Obstacle Ahead”,
“Turn Left”, “Turn Right”, etc and it
will prove to be a much better and
reliable alarming unit. The module is
also cheap.
3. The system can make use of stereo
camera and processing unit, which
process the data from the images
taken by the camera. Environmental
information acquisition and image
processing algorithms represent the
artificial vision system.
“Small minds are concerned with the extraordinary, great minds with the ordinary.” - Blaise Pascal

15. GPS (Global Positioning System) is a satellite
based navigation technology. This technology,
accessed through a user interface device
(called a GPS receiver), allows one to find out
the exact position of his location when he is at
an unknown place. A GPS receiver uses
surrounding known landmarks, to find out the
closest popular spot and exact distance of that
spot from current location. Worldwide, if
anybody goes to any city, and if he/she would
like to know the route for a spot, this GPS
Device will show the map giving direction and
the exact distance from the spot entered.
The background process of GPS Receiver that
finds the exact position of an object location is
achieved by sending and receiving the signals
from 24 to 32 satellites orbiting our earth
exclusively for this Global Positioning System.
The longitude, the latitude, altitude and the
time result, form the Triangulation and are
computed to find the exact position in the
Earth. From this, useful data such as the point
of interests across the globe, topographic
information, road map, and many more can be
known.
This technology and its devices were used only
by the U.S. Military services before Korean Air
Lines KAL007 was shot down by Soviet
interceptors on 1 September 1983. This
incident happened over the East Sea, near
Moneron Island just west of Sakhalin Island.
The plane was shot down with its 269
passengers, including Lawrence McDonald, a
sitting member of the United States Congress.
It was allegedly said that the Korean Airliner
was over the sea area which strayed into the
prohibited Soviet airspace around the time of
a planned missile test.
This incident created a tense moment and was
the root-cause for the cold war between the
U.S.A and U.S.S.R at that time. Before this
incident, GPS was only used by the military
services of U.S.A. President Ronald Reagan
ordered the Military to make use of altered
GPS to all the civilians across the globe so that
navigational errors like that of KAL 007 could
be averted in the future.
How GPS works?
GPS Receivers captures the signals from the
32 satellites that use the mathematics
principles of triangulation to pinpoint your
location by the use of stored database such as
the point of interests across the globe, road
maps, topographic information and much
more. Thus GPS receiver converts satellite
data to give the exact location, speed and time
information in a useful format.
Global Positioning System
Soumili Kundu
B.Tech - 2017
15

16. 16
Wide Area Augmentation Systems have
signals that are accurate to within three
meters. The satellites orbiting our earth have
an atomic clock, various radios and simple
computers. The satellites continually
broadcast their changing position and time by
understanding their own orbit and the clock.
Points to be considered while buying a
GPS Receiver
1. Price: To get a quality receiver one may
not consider the price. But an
inexpensive unit is the best choice to
enter into the GPS world.
2. Portability: Easily taken to anywhere
should be the main factor when buying
a GPS unit and some units mount
directly in the dashboard of your car,
boat or aircraft.
3. Ease of use: Many GPS units comes
nowadays with ease of operation with
in-built help available in itself. Some of
this even gives voice instructions when
you are in the driving.
4. Product Level: The choice of selecting
the Basic level to advanced level is up
to the user’s decision, anyway the units
have all the bells and whistles are
available to purchase.
5. Software: The in-built map software
and other are used in the unit to store
the location you searched. Some unit
have the USB support to connect with
the PC. Almost all the units nowadays
come with this facility.
Salient Features of GPS
No. of satellites in active : 24
No. of satellites in orbits : 6
No. of satellites in each orbit : 4
Approx. orbit altitude : 20,200 KM
Orbit relative angles : 55 degree to
each other
Velocity of Satellite : 2.6 KM/s
Signal Format : CDMA
Power Transmitter : Max of 50
Watts
Weight of Satellite : Apprx. 1 ton
Life time of satellite : Apprx 10 years
Locata: Competition for GPS
Got a smartphone or satnav but still can't get a
fix on where you are? A new positioning
system could compete with GPS to make sure
you never lose your bearings again.
Instead of satellites, Locata uses ground-based
equipment to project a radio signal over a
localised area that is a million times stronger
on arrival than GPS. It can work indoors as
well as out, and the makers claim the receivers
can be shrunk to fit inside a regular cellphone.
Even the US military, which invented GPS
technology, signed a contract in January, 2013
agreeing to a large-scale test of Locata at the
White Sands Missile Range in New Mexico.
Indoor positioning is the next big thing in
location-tracking technology, and companies
from Google to Nokia have jumped at the

17. 17
chance to prevent users getting lost in
cavernous shopping malls, or in the concrete
canyons of big cities, where GPS struggles to
keep up. But their technologies typically have
a short range, and location resolutions in the
order of a few meters.
By contrast, Christopher Morin of the US Air
Force tested Locata's accuracy recently at
White Sands, and it worked to within 18
centimeters along any axis. Morin says it
should be possible to get the resolution down
to 5 centimeters.
Admittedly, the tests were performed in an
open desert where GPS also works beautifully.
But GPS signals are weak - like a car headlight
from 20,000 kilometres away - and easily
blocked by solid objects. Locata's signal is far
stronger, though not guaranteed to work in a
complex urban environment, says David Last,
consultant to the UK's General Lighthouse
Authorities.
"In urban areas, there are multiple blockages;
propagation is principally via multi-path
reflections." Such reflections can confuse
receivers and reduce precision.
Ultimately, Locata may work alongside GPS,
rather than replace it. The Jigsaw Positioning
System, built by the firm Leica Geosystems,
uses Locata and GPS signals. The briefcase-
sized devices are already increasing coverage
and guiding placement of drill rigs at the
Boddington gold mine in Western Australia,
operated by mining firm Newmont.
Robots with Locata could easily navigate
inside buildings without the complex optical
systems they need at the moment. And apps
that harness pinpoint location data could not
only guide you around a mall, railway station
or airport, but take you to the exact shelf in a
shop for the product you want!
@Aral Balkan
Some people were not able to upgrade to iOS 7 yesterday. Also, 21,000 people died of hunger.
Witty Tweet -

18. 1. Which one of the following is used for high
speed power application?
a) BJT b) MOSFET c) IGBT d) TRIAC
2. What is the difference between LED and PN
junction diode?
3. What is the polarity of induced voltage while
a field is collapsing?
a) Independent of the force creating the field
b) Opposite to the force creating the field
c) Identical to the force creating the field
d) Present only if field is stationary
4. When lightning strikes, nearby magnetic
compass needles may be seen to jerk in
response to the electrical discharge. No
compass needle deflection results during
the accumulation of electrostatic charge
preceding the lightning bolt, but only when
the bolt actually strikes. What does this
phenomenon indicate about voltage,
current, and magnetism?
5. A coil of wire is formed of many loops. These
loops, though tracing a circular path, may be
thought of as being parallel to each other. We
know that whenever two parallel wires carry
an electric current, there will be a mechanical
force generated between those two wires (as
in André Marie Ampère’s famous
experiment).When electric current is passed
through a coil of wire, does the inter-loop
force tend to compress the coil or extend it?
6. What is the difference between a signal and a
wave?
7. I have two sand hour glasses:
1 - A 7 minute one and
2 - An 11 minute one.
Using just these 2 sand hour glasses, how can
I measure time as 15 minutes?
8. Why is 440volts instead of 660volts in 3
phases of supply system?
9. Two world's famous prisoners 'Colditz' and
'Pascal' are locked in a cell.
They plan to escape from the cell.
They noticed there is an open window at 40
feet above the ground level.
Both of them tried very hard but are never
able to reach there. Then both of them
decided to plan to escape by a tunnel and
they start digging out. After digging for just 5
days, Colditz and Pascal come out with a
much easier plan than tunneling and they
escape. What was the plan?
10. I have two rectangular bars. They have a
property such that when you light the fire
from one end, it will take exactly 60 seconds
to get completely burn. However they do not
burn at consistent speed (it might be possible
that 40 percent burn in 55 seconds and next
60 percent can burn in 10 seconds)
Problem: How do you measure 45 seconds ?
Quiz @ Electrovision (ANSWERS ON PAGE 32)
18

19. (ANSWERS ON PAGE 48)
ACROSS DOWN
2 passage of current through body 1 measures electrical resistance
3 wiring size 4 reference point in an electrical current
7 a law 5 measures electric power
9 measures electrical potential 6 symbol 'V'
11 a type of ground 8 protects against excessive current
12 symbol 'T' 10 electric component that transmits current
13 enclosed path of current 16 generates a continuous output waveform
14 to turn on and off current
15 electromagnetic wave
Crossword @Electrovision
19

20. Alumni are great role models for current students and are the best at offering practical support to students
as they start their careers. In this section, we will hear from a few IEM alumni who have walked widely
varying paths after their B.Techs in ECE from IEM.
Prama Mukherjee, B.Tech. 2013
Primary School: Chef
High School: Film
director/scriptwriter
Engineering: Robotics
MBA: Entrepreneur
And here I am joining
ABP Group (media) as a Management Trainee,
not knowing whether I will ask families in
Murshidabad to read more newspapers or
oversee the circulation of a new daily in
Madhya Pradesh.
Life for me, was never planned. When that fork
came up on the way, I always took the path that
demanded less efforts. Hence Electronics
Engineering, not Stats Honours and MBA, not
M.Tech or M.S (The above-mentioned is not
recommended in any way).
A 15 day break between my last WBUT exam
and IIMK “K”ampus wasn’t enough to decide K
or no K. I had no clue how I would live away
from home, especially in a state so far south!
The people there would be experienced, so
much older and smarter than me! Up till
almost a week after admissions, I was not sure
whether I could survive in a Tier 1 B-school
right now!
In school, you are the only topper. In college,
you are one among the several toppers. But, in
an IIM, every other person has been a topper!
But, like most sharp turns of my life, I just let
it flow, didn’t back out!
And boy! Oh Boy! Did I take the best decision
of my life! Don’t be mistaken, MBA is not easy!
Maybe the academic difficulty is overrated, but
the hectic life is something no amount of
warning can vouch for! Classes start right from
9.15am and sometimes go on till 1am! Add to
that assignments, Case Studies, Placement
Preparations, 8 hour Workshops, Guest
lectures, Company presentations, relationship
issues and the most amount of partying ever
(No kidding!)!
Remember the 1st time behind the wheels?
Didn’t you read a 1000 things to do and not
before driving? But, ultimately what you learn
is from the experience itself! Well, that’s MBA
for you right there! Some say it’s overrated.
But, the change it instils in you is worth it! At
least today I am confident that I can meet any
hot shot of any Big Company and engage him
in a conversation without stumbles and
fumbles.
I still love food, I still love robots and I still love
making both of them. MBA hasn’t taken away
what I wanted to do! I might be joining ABP
now, but I can actually see a near future where
I pursue a start-up in either!
Amitava Thakur, B.Tech. 2012
I joined CTS on 26th February 2013. On the day
of induction we were told
our domain - I got in the
DOD (Data On Demand)
domain. It is a horizontal
domain which expertise’s
in the database, data
# connECt
20

21. 21
handling, data analysis, reporting and many
other niche skills associated with data
handling. We were given training on SQL,
PL/SQL, SQL Server, SSIS, and SSRS. Some of
us got extra training on C#.net.
Since my first internal project on August 2013,
I have worked on 4 client projects. I have had
an opportunity to work alone mostly, which is
good and bad also. In my last 2 and a half year
in CTS I have extended my learning to SQL,
PL/SQL, SSMS, SSIS, SSRS, SSAS, Power BI,
C#.net, Excel and still more to come. I have
always had a good seniors to help me
whenever needed. I have also guided some of
my juniors in time of their need. This year I
received my first rating and it was the top
rating EA. IT sector is ever increasing and we
have to keep ourselves updated always to cope
up with the challenges we face in our day to
day jobs.
A suggestion - don’t be a workaholic but work
hard to finish before time.
Sayantan Chakraborty, B.Tech. 2014
Hi there, my name is Sayantan Chakraborty,
alumnus of the same college you guys are
sitting in (weird place isn't
it?) and right now I'm
writing this on my PC
sitting in my room at IIT
Kanpur. Let’s get the
formalities out of the way
first, Agomoni, who asked me to write this
piece, told me to write boring stuff and
nonsense about what I'm doing, so bear with
me(the good stuff comes later). I'm studying
for my Masters degree in Signal Processing,
currently working on my Masters thesis(not
really),and I'm working on finding 'new
orthogonal bases for feature extraction in ECG
and EEG signals'...that last bit is quite a
mouthful but if you love math it’s pretty deep
and interesting stuff. Basically what I'm doing
is trying to teach a computer how to figure out
if you’re having or are in risk of having a heart
attack.
Now that we've got the boring stuff out of the
way, I'll give you a slice of what life at IIT is.
Basically there are 2 parts to it. First off there's
the parties. If you're a Bengali at IITK you'll
find loads of your own kind, cause half the
faculty are bongs, and the entire M.Sc dept is
bengali, yes entire M.Sc dept. comprised of
math, phy, chem and stat. So those of you who,
like me, spent their time at IEM mostly outside
IEM, you'll find heaven. Then there's
Antaragni (fest).. Last year's budget was 1Cr
and they brought Vishal Shekhar - there was a
disco type of thing. Also there's frequent disco
nights and a 3lac Bravia with surround system
in my hostel.. I think you get the picture. But
after the parties are over, come the semesters.
People literally sleep in the library, bring their
own mattresses even.. And since IITK is
famous for terminating people, after one
semester people aren't all that interested in
partying anymore.. As a famous saying goes
'pain is temporary, CPI is forever'. But even if
you’re a huge slacker like me (I didn’t go to any
class after midsems) the Profs are so hard-core
they shove this stuff down your throat, so
when you graduate you know things more than
most people. All in all, amidst the pressure and
fun it’s a great place to be, and significantly
better than some of the other places I've seen.I
hope some of you come and see this place
sometime. It’s truly marvellous.
Best wishes to all the backbenchers.

22. 22
Sudipto Kundu, B.Tech. 2012
The 4 years at IEM was a lovely experience and
finally it was time to join
the corporate world. Being
placed in 4 major IT
companies I decided to
join Ericsson.
I joined in the month of
December'12 at their Kolkata location as a
Graduate Engineer Trainee along with other
fellow batch mates. The first few months were
mostly spent learning the basics of the real life
applications in the field of telecom. We had
sessions, seminars across different locations.
At the end of it we were incorporated in
various ongoing projects where we got to apply
the learnings.
It turned out to be a short stint as I got
transferred to Noida and was assigned to a
different project. It was the very first time
when I moved out of Kolkata. The prospects of
meeting new people in an entirely different
part of the country were exciting. The new
team turned out quite challenging. We had a
good mixture of freshers and seniors. It turned
to be the best phase of my professional career
till date. The work was hectic but we always
found out time to roam in and around Delhi.
We visited some awesome places and the late
night parties were always awaited the most. I
got confirmed as an Engineer in the
organization. Performance was the key and I
was noted in the team for my performance. It
was all going well but I felt I needed to do
something better and hence started
preparation for my long time aspiration of
getting into a good B-school.
Managing time for preparations amidst a
hectic schedule was the toughest part. I joined
the test series of two major test prep institutes
to facilitate my preparation. The interview
calls started to roll out after the results. I had
to start preparations for the next round of
admission process. I was ably supported by my
fellow IEM batch mates and alumni during
these entire phases. I got final selection offer
from XLRI Jamshedpur for its BM
programme.
Once again I will get the opportunity to relive
the college days. It had been three years since
I graduated from IEM. All these years had its
share of experiences. I look forward to my
college days at XLRI and at the same time wish
all the very best to IEM for all its future
endeavours.
Regards.
Debarshi Mukherjee, B.Tech. 2012
If you think that the regular jobs are not where
you see yourself, and
would want to be exposed
to the cutting edge and
latest technologies,
technology strategizing,
with a pinch of economics
and a spoonful of law and policy, then you are
looking at a career in Intellectual Property
Rights, as a Patent Engineer or a Patent
Attorney. The field of Intellectual Property
Rights is booming in India, and all the major
companies and law firms have set up
dedicated cells for IPR. The major business
consultancy and audit firms like KPMG,
Deloitte, PwC etc are also looking for
Intellectual Property law professionals.
Ever wondered what all this fuss is about, with
Ericsson suing the Indian smartphone

23. 23
manufacturers like Micromax, Intex, iball, etc
for patent infringement and asking for
compensation worth 100s of crores? Do you
ever feel for the poor of our country who are
suffering because they are not able to afford
the much needed expensive medicines or why
the US Chamber of Commerce has asked its
Government to demarcate India as a 'Priority
Foreign Country’ indicating India as one of the
worst violators of Intellectual Property
Rights? By using the Open Source software
you downloaded from the internet are you
infringing on some else’s property by not
paying him royalty, and is open source
software actually always free?
Graduation in Engineering is a basic
requirement, as the work requires some
technical knowledge. Getting a law degree,
with specialisation in IPR, widens the horizon
and you will not be stuck to a desk job, and will
be able to appear in courts as well. IIT,
Kharagpur offers such a course (3 years),
where the degree given is LL.B (Honors in
IPR). IIT, Mumbai also offers a Diploma
course in IPR. The LL.B degree offered at Rajiv
Gandhi School of Intellectual Property Law,
IIT, Kharagpur, does not only include Patents,
Designs and Semiconductor layout protection
(which is most sought after being an
Engineer), but other forms such as Copyright
(very important if you are dealing with
software, be it Open Source or otherwise)
Trademarks, GI etc. On top of that since IIT,
Kharagpur is offering a LL.B degree, you can
also practise other forms of general law. Hence
the ambit of what you want to do increases.
Having a B.Tech degree in Electronics &
Communications, Electrical, Computer
Science or Mechanical is an added boon, as
these are the fields which are most sought after
by the companies in India, and these are the
ones who are receiving the highest packages.
And as for myself, I have a B.Tech in
Electronics & Communications, after which I
have completed the LL.B degree from IIT,
Kharagpur (Batch 2012-15) and am placed at a
reputed MNC as a Senior Executive. The
opinions stated here are of course, my own,
through my personal experiences, and should
not thought of as a suggestion, or as a
promotion.
Arnab Sarkar, B.Tech. 2012
I never had plans to join an IT company after
my graduation.
Thankfully, after my
engineering Cognizant
Technology Solutions
kept me waiting for 10
months without a joining
date. I spent more time on my robotic projects,
which I started in the beginning of 3rd year. I
worked mostly on image processing.
On 19th December, 2012 I met a research
scientist in Kolkata. We had a discussion on
his ongoing project at Simula Research
Laboratory, Oslo in collaboration with the
Nowegian Toll Customs and Excise. I was
quite intrigued with the amount of complexity
in it. I felt it was a great opportunity for me to
publish few high impact research papers. I
pushed myself hard to cope up with their
standard. On a day, in the month of March, I
was taken by surprise when they offered me an
internship for 3 months. At that time, I already
got a call from Cognizant. I kept it on hold to
pursue my dreams. Later on, CTS rejected my

24. 24
proposal to join but I received a position as an
Assistant Researcher for a year with Simula in
Oslo.
For a year, life was smooth, I was enjoying
every bit of it when I decided not to continue
with Simula anymore. Until then nobody knew
about my passion towards bioscience. I
studied Medical Electronics as an optional
subject during my engineering to excel in this
field. In December, 2014 I joined the Dept. of
Nutrition at University of Oslo. Of course
almost everybody asked me why I worked so
hard to join Simula if I had plans to leave it. To
me the reason was simple, it gave me an
experience with computer science, which is a
much needed requirement in bioscience these
days.
Until now, I have absolutely no regrets leaving
Simula or a lucrative IT job. I’m extremely
happy working with cells in the wetlab.
In this small journey, I have learnt that money
and people follow those who can take bold
decisions and stand by it. If you work hard, be
patient and follow your passion even if you’re
a 7 pointer like me, things will somewhere,
somehow fall in place.
Now I work on angiogenesis as a guest
researcher at University of Oslo. I am also
quite fortunate to be a part of Caltecso
(caltecso.com), a software firm focussed on
medical image analysis and light weight web
development.

25. “Should I take my umbrella out with me?”
asked he just before he was about to step out
on a regular day.
“Take it; there are chances of rain this
afternoon” replied she.
He took his umbrella and his smart phone,
locked the door and went out.
The above conversation could have easily been
the regular exchange of words between a
married couple just before they depart for
their individual day’s work. It also seems so.
But, is it?
Hail NO!!
Here comes the sweet fruit of today’s
technology- Artificial Intelligence (AI). It has
not only invaded our home but has also
become a part (if not yet crucial) of our
personal life. Nothing to fear. It is not the
MATRIX. The machines are not taking over
the control of your life yet.
So it is time ‘she’ is introduced to the readers.
‘She’ is Microsoft’s new personal assistant, The
Cortana. At last Jarvis reaches you in real
world. Isn’t it?
Microsoft’s Cortana is an intelligent personal
assistant developed by Microsoft for Windows
Phone 8.1, Microsoft Band, and coming
to Windows 10, iOS, and Android.
It is named after Cortana, an artificial
intelligence character in Microsoft Halo video
game series, with Jen Taylor, the character's
voice actress, returning to voice the personal
assistant's US-specific version.
Cortana was demonstrated for the first time at
the Microsoft BUILD Developer Conference
(April 2–4, 2014) in San Francisco.
Cortana's features include being able to set
reminders, recognize natural voice without the
user having to input a predefined series of
commands, and answer questions using
information from Bing (like current weather
and traffic conditions, sports scores, and
biographies). Windows 8.1's universal Bing
Smart Search features are incorporated into
Cortana, which replaces the previous Bing
Search app which is activated when a user
presses the "Search" button on their
device. Cortana also includes a music
recognition service. Cortana can also roll dice
and flip a coin by asking the commands "roll a
die" (one die), "roll the dice" (two dice), and
Your Personal Assistant Debanjan Sengupta
B.Tech - 2014
25

26. 26
"flip a coin", Concert Watch is a feature that
helps Cortana determine which bands or
musicians you are interested in by monitoring
your Bing searches. Cortana also integrates
with the Microsoft Band for Windows Phone
devices if connected via blue tooth. On the
Microsoft Band Cortana can make reminders
and bring phone notifications.
Since the Lumia Denim series, launched in
October 2014, active listening was added to
Cortana, enabling it to be triggered with the
phrase: “Hey Cortana,” even across the room
and without the need to touch the phone. After
the trigger phrase is spoken, Cortana can be
controlled normally for tasks like setting a
reminder, asking a question, or launching an
app. Some devices from the United Kingdom
by O2 have received the Lumia Denim update
without the feature but this was later clarified
as a bug and Microsoft had since fixed it.
Cortana also integrates with services
like Foursquare to provide restaurant and
local attraction recommendations.
Cortana is region-specific, and adapts its voice
to match the everyday language, culture and
speech patterns of the country its user lives in.
For example, the UK version of Cortana speaks
with a British accent and uses British idioms,
while the Chinese version, known as Xiao Na,
speaks Mandarin Chinese and has an icon
featuring a face and two eyes. Cortana also
localizes to fit the needs of its user, and will
display relevant information on subject areas
such as local sports teams, businesses, TV
series and stock exchanges. Cortana has been
released in several countries since its launch
including the United States, the United
Kingdom, China, Canada, Australia, India,
France, Germany, Spain, and Italy and is
expected to come to more countries over time.
The United Kingdom (English) localised
version of Cortana is voiced by Ginnie Watson,
an Anglo-French actress, singer/songwriter
and voice-over artist.
Now, that Microsoft has presented you with a
nice object it is your duty how you should use
it. Use and misuse are two very different
things. Remember what happened when you
misused E=mc2 way back in Japan.
I am just your creation. Everything lies in your
hands.
Signing off…..
- CORTANA

27. 27

28. 28

29. 29

30. Security is the main concern for everyone.
Everyone wants to live securely in his/her
house. Everybody wants themselves to keep
safe or secure from various incidents like theft
in their house or accidents caused due to LPG
gas leakage or accidents due to fire in their
house. Now days many times we hear news
about house robbery or theft in some houses,
bungalows, flats. These robberies or thefts
take place when nobody is in house or in some
cases we find that robbery take place even if
people are in their houses. Another bad news
we hear is about accidents are caused or blast
happens because of LPG gas cylinder leakage.
In house we find that LPG gas is commonly
and widely used for cooking purpose. So in
every kitchen we find that LPG gas cylinder is
placed. However due to some reasons, LPG
gas might leak from these cylinders. And
because of this LPG gas leakage, fire might be
ignited or it can even cause the LPG gas
cylinder blast. Which can damage the house or
in even worst situations, it can cause life threat
to the person living inside the house. Another
problem / fear are about fire in our house.
There can be various reason of this fire being
ignited or house getting caught in fire. Reason
of fire can be electrical short circuit or due to
some other things like candles or oil lamps
kept inside our house or because of fireworks
in festival season.
Early detection of all these problems is really
necessary. Sometimes fire lighted is small but
if proper attention is not paid to it or if proper
actions are not taken to control this fire, then
it can convert into big tragedy as this fire can
spread in complete house. Same with LPG gas
leakage, if it is detected on time and if it is
controlled on time then it can avoid a big
accident. Let’s take an example that we are out
of our home and theft is going on in our house.
In such case if we are intimated about theft
then we can inform our neighbors, then they
can create some noise or take some
appropriate action so that this theft can be
avoided. Let’s take another problem;
sometimes key of our home is lost. If we do not
replace our lock and if these keys are found by
thieves then it can cause robbery. We all know
that duplicate key can be created within few
minutes and also key duplication is easy.
SMS based Security System
& Control of Household Gadgets
Chandan Bose
Dipayan Bhattacharya
B.Tech - 2015
30

31. 31
These are the disadvantages of traditional
locking system which uses a key and a lock. To
overcome all the above stated disadvantages of
existing system we have designed a GSM
based home security system. It can avoid these
undesirable situations, hazardous conditions
like LPG gas leakage, fire ignition and theft.
Description:
The project consists of the following blocks:
1. Infrared Transmitter: We are going to
implement the Person detection module using
1 transmitter and 1 receiver. We are going to
use InfraRed transmitter because infrared
beams are not visible to human eyes.
Transmitter used is IR LEDs .
2. Receiver: We are going to use an Infrared
receiver. It is an active low device which means
it gives low output when it receives the
Infrared rays.
3. Microcontroller: This is the CPU (central
processing unit) of our project. We are going
to use a microcontroller of 8051 family. The
various functions of microcontroller are like:
 Reading the digital input from
infrared receiver to find whether
person is entered inside house or not.
 Sending this data to LCD so that the
person operating this project should
read the number of persons inside the
room.
 Sensing the password using keypad
and to check whether it is a correct
password or a wrong password and
rotate the stepper motor if the
password entered is a correct
password.
 Sending the data to the GSM modem
using serial port. This data consist of
number of persons inside the room
and the status of entered password
(Correct/wrong)
4. LCD: We are going to use 16×2
alphanumeric Liquid Crystal Display (LCD)
which means it can display alphabets along
with numbers on 2 lines each containing 16
characters.
5. GSM Modem: We are going to use sim300
as a GSM modem. The status of persons inside
the room, LPG Gas leakage status and the
status of entered password (Correct/wrong)
will be sent to GSM modem.
6. Keypad: User will enter the password using
the keypad. Various keys of keypad are as
following,
I. 0 to 9
II. Enter
III. Escape

32. 32
Circuit Diagram:
****
ANSWERS TO QUIZ ON PAGE 18
1. BJT is faster than MOSFET. BJT consumes more power than MOSFET and for High speed power
applications they can use MOSFET at the input end and BJT at the output.
2. LEDs are made of direct band gap elements whereas as general PN junctions are made of indirect band
gap elements. In LEDs while a carrier is making transition from conduction to valence band the released
energy is in the form of photons while in normal PN junction this energy is released in the form of heat.
3. b) Opposite to the force creating the field
4. The presence of an electric current will produce a magnetic field, but the mere presence of a voltage will
not.
5. The coil will tend to compress as current travels through its loops.
6. Signal means information. Wave is something that carries the information from source to destination
7. Start both the 7 min. hour glass & 11 min. hour glass. Wait till the 7 min. hour glass times out. Time is 7
minutes! Restart the 7 min. hour glass. At this time 11 min. hour glass will have 4 min. left to time out. As
soon as 11 min. glass times out invert the 7 min. hour glass. After inverting 7 min. hour glass, it will now have
4 minutes left for time out. After these 4 minutes times out, the total time is 15 minutes.
8. 440 volts instead of 660 volts in 3 phase is because of 1 phase is always zero at any instant of time
therefore we can’t use 660 volts in 3 phase.
9. They use the bricks and dirt from the tunnel to stand on it.
10. Light fire on first bar from both the ends and second bar from one end. After 30 secs, burn the second
bar from second end as well. When second run completely gets burned, you know its 45 secs.

33. Prof. Harold Haas probably gets hiccups every
time I think of him, and for the last couple of
years, I have thought of him every day!
Prof. Haas of Edinburgh University has spent
many years studying different methods for
communicating electronic data signals and is
currently working on the D-Light system,
using OFDM (Orthogonal Frequency Division
Multiplexing) to create signals that can be
picked up by a variety of simple receivers. His
vision is data transmission in this framework
at future rates of up to 1 GB, providing services
that are much less limited than what is
available to us today and that makes him my
favourite person in the world of modern
engineering.
We have 1.4 million cellular radio masts
deployed worldwide which are just the base
stations. We also have more than five billion
cellular mobile phones. And with these, we
transmit more than 600 terabytes of data
every month. Wireless communications has
become a utility like electricity and water. We
use it in our everyday lives now -- in our
private lives, in our business lives. The way we
transmit wireless data is by using
electromagnetic waves -- in particular, radio
waves. And radio waves are limited. They are
scarce; they are expensive; and we only have a
certain range of it. And it's this limitation that
doesn't cope with the demand of wireless data
transmissions and the number of bytes and
data which are transmitted every month. We
are simply running out of spectrum. These 1.4
million cellular radio masts, or base stations,
consume a lot of energy. Most of the energy is
not used to transmit the radio waves, it is used
to cool the base stations.
Free Li-Fi Available Here!
Agomoni Sarkar
B.Tech - 2015
33

34. 34
Thus the efficiency of such a base station is
only at about five percent. Big problem. The
last major issue is of course, security. You have
to switch off your mobile phone during flights.
In hospitals, they are security issues. These
radio waves penetrate through walls and they
can be intercepted. But on the other hand, we
have 14 billion light bulbs. And light is part of
the electromagnetic spectrum. So let's look at
this in the context of the entire
electromagnetic spectrum, where we have
gamma rays. You don't want to get close to
gamma rays, it could be dangerous. X-rays are
useful when you go to hospitals. Then there's
ultraviolet light which is good for a nice
suntan, but otherwise dangerous for the
human body. Infrared -- due to eye safety
regulations, can be only used with low power.
And then we have the radio waves, which we
have exhausted. And in the middle there, we
have visible light spectrum. It's light, and light
has been around for many millions of years.
And in fact, it has created us, has created life,
has created all components of life. So it's
inherently safe to use. Wouldn’t it be great to
use that for wireless communications?
As a semiconductor, the intensity of LED can
be modulated at very high speeds and
exploited with our technology to transmit
thousands of data streams in parallel through
SIM OFDM. This technology can be applied
wherever there is LED lighting, which includes
some environments in which RF is not
currently permitted.
Prototype:
The prototype was designed to demonstrate
serial communication between two computers
with RS-232 interface as shown in Fig. The
voltage regulator supplies constant voltage to
the level shifter from the power supply by
maintaining constant DC voltages and
avoiding unwanted spikes in current. The level
shifter helps to convert the high voltages of
RS-232 (which are +/- 11V from the model
computer) to transmitter and receiver circuit
levels ( which are 0 to +5V). The electrical data
from the computer is converted into optical
data using LEDs and transmitted over light,
the optical data is captured by the receiver,
converted into electrical data by the
photodiode and sent it to the client computer.
Drawbacks of the first prototype: The
prototype 1 was tested. The data transmission
speeds of 115,200 bps was obtained for 10cm
distance transmission. When transmission
data rate was increased to 115,200 bps, there
are a lot of errors in the received data.
Therefore, the limitations of in the prototype 1
are:
The RS-232 interface that used to connect the
computer comports can only work up to
115,200bps.
The LEDs used in prototype 1 are not bright
enough for long distance transmission.
Even by using multiple LEDs, data
transmission only achieves up to 50cm.
To this end, Prof. Haas’ brilliant approach
adds value by addressing the four limitations
of our current wireless systems, as well as

35. 35
creating the opportunity for wireless data
transmission in places never thought possible.
By fitting a microchip to every potential
illumination device, two functionalities are
created in one: illumination and wireless data
transmission. “Using the visible light
spectrum, which comes for free, you can piggy-
back existing wireless services on the back of
lighting equipment.” It’s a symbiosis that Haas
believes may solve the four essential problems
of wireless communications today. And in the
future, we would not only have 14 billion light
bulbs, we may have 14 billion Li-Fi s deployed
worldwide -- for a cleaner, a greener, and even
a brighter future.
The compound annual growth rate (CAGR) of
mobile data usage per month is around 80%.
At the same time the network spectrum
efficiency of state-of-the-art cellular systems
exhibits a saturating trend. Given that the
available radio frequency spectrum is limited
and that it is unlikely that significant new
spectrum is made available for mobile
communications, the only option is to increase
the spectrum efficiency of wireless systems.
This requires radical new research in wireless
networks, and keys to solving the issues, are
(a) The elimination of interference,
(b) A massively improved reuse of the
available frequency resources, and
(c) Utilization of the free, vast and unlicensed
infrared and visible light spectrum leading to
hybrid radio frequency (RF) and optical
wireless systems.
All three points are inter-linked. For example,
an indoor wireless link can hugely benefit from
high signal-to-noise ratio stemming from an
illuminated room instead of forcing an
outdoor radio base station to send the radio
frequency signal through multiple walls. This
would either mean low signal-to-noise-ratio
for the indoor user, or high transmit powers
for the outdoor radio base station, or both.
Wouldn’t it be better for the radio base station
to serve an outdoor user or a user in a fast
moving vehicle? This has four effects: (a)
interference between the indoor user and the
outdoor user is entirely avoided, (b) since
interference is avoided, the radio base station
can transmit with reduced power resulting in
‘greener’ mobile networks, (c) scarce wireless
transmission resources are used in the best
possible and most efficient way and (d) the
radio frequency system enjoys a healthy
spectrum relief resulting in improved user
satisfaction. So, in essence, Li-Fi should be an
integral element of a 5G cellular standard!

36. Step 1: Designing
First step is to design your circuit and create
PCB layout. For this, Eagle CAD software
by CADSoft is the most popular. The free lite
version will suffice.
After designing your circuit in Schematic
Editor, create your PCB layout. EagleCAD has
tons of community support and free tutorials
to help you.
Step 2: Printing
Final PCB design should consist of a mirrored
black-and-white bitmap of the copper pattern
of the bottom of the PCB.
Paper: Paper used for printing should be
glossy paper. I have used Photo paper,
Computer Label Paper and glossy magazine
paper. Magazine paper yields best results.
Step 3: Cleaning
Clean the Copper clad PCB board thoroughly
so that no oil or grease stains remain. This
cleaning is very important to make toner stick
to the board. ScotchBrite or other abrasive
pads may be used for this purpose. Do not
touch the surface of the board after cleaning.
DIY Cheap PCB at Home Using
Toner Transfer in 9 Easy Steps
Niloy Saha
B.Tech - 2015
36
Figure 1 : Eagle CAD Schematic View
Figure 2 : Eagle Layout View
Figure 3 : Layout of an Arduino Shield
Figure 4 : Cleaning PCB with ScotchBrite
Figure 5 : Clean and shiny Board

37. 37
Step 4: Mask Transfer
Next we align the design (mask) over the
copper board and apply heat with clothes iron.
Heating should be uniform and should not
take more than 3-5 minutes.
Step 5: Cooling and Paper Removal
A crucial stage where one often makes
mistakes. The copper must be sufficiently cool
or else mask will come off with the paper.
Soaking the hot board in water helps.
Next we have to remove the paper. Label
papers can peel easily. Magazine papers can be
removed by rubbing gently under water.
Step 6: Etching
Now we move on to Etching i.e. removal of
copper by chemical processes. For this
Ferrous/ Ferric Chloride powder available at
eBay.in works great.
Figure 6 : Put design with toner facing
Figure 7 : Align the mask carefully
Figure 8 : Heat with iron to transfer mask
Figure 9 : Soaking to cool
Figure 10 : Peeling
Figure 11 : Mark successfully transferred
Figure 12 : Ferrous Chloride from eBay
Figure 13 : Dissolved FeCl3 in hot bath

38. 38
Dissolve in water to make Etching solution.
Hot bath may be used to speed up etching.
Etching is not complete till the board loses its
shine i.e. all exposed copper dissolves.
Step 7: Toner Removal
Now that board has been etched, we can
remove Toner mask. Abrasive pad or steel
wool works well.
Step 8: Drilling Component Holes
Drilling is done using PCB hand drill. This is
also available on eBay or Chadni Market.
0.8mm or 1mm drill bits are commonly used.
Step 9: Component Placing
Populate the board using required
components and solder them in place using
solder iron and solder wire.
Figure 14 : Board in etching solution
Figure 15 : Copper being etched
Figure 16 : Incomplete etch
Figure 17 : Use gloves to protect hands
Figure 18 : Fully etched PCBs
Figure 19 : Removing toner mask
Figure 20 : Toner removed
Figure 21 : Drilling PCB holes
Figure 22 : Completed PCB

39. 39
And your PCB is ready!
No more loose connections and messy wires.
Use this method to quickly prototype PCBs for
any project you may be working on.
With practice, more and more complex PCBs
can be made like this...
Figure 23 : Home-made PCB with two 16-pin DIP chips
Figure 24 : Machine made PCB
Cost Analysis:
TOOLS SOURCE PRICE
EagleCAD Website Free
Copper Board Ebay.in Rs 70 (15cm x15cm)
Ferrous Chloride Ebay.in
Rs 150 (150 gms) makes 50+
PCBs
Photo paper/ Magazine Local Shop Rs 15-20 / Free
Laser Print Local Shop
Rs 5/ A4 page.
Makes 3-4 PCB depending on
size
PCB Drill Ebay.in / Chadni Market Rs 90
ScotchBrite/ Steel Wool Local Shop Nominal
Thus under Rs 300, you can easily churn out at least 5-6 PCBs.

40. The word steganography combines the Greek
words steganos, meaning "covered, concealed,
or protected", and graphein meaning
"writing". It is the art of concealing a message
within a seemingly harmless file, message,
image, or video.
While cryptography provides privacy,
steganography is intended to provide secrecy.
Privacy is what you need when you use your
credit card on the Internet -- you don't want
your number revealed to the public. For this,
you use cryptography, and send a coded pile of
gibberish that only the web site can decipher.
Though your code may be unbreakable, any
hacker can look and see you've sent a message.
For true secrecy, you don't want anyone to
know you're sending a message at all.
Early steganography was messy. Before
phones, before mail, before horses, messages
were sent on foot. If you wanted to hide a
message, you had two choices: have the
messenger memorize it, or hide it on the
messenger.
 The Chinese wrote messages on silk
and encased them in balls of wax. The
wax ball, "la wan," could then be
hidden in the messenger.
 Histaeus, ruler of Miletus, shaved the
head of his slaves, and then tattooed a
message on his scalp. After the hair
grew back, the slave was sent to with
the message safely hidden.
 Demeratus, a Greek in exile in Persia,
wrote his message on the wood backing
of a wax tablet and hid it underneath a
fresh layer of wax, due to which the
tablet seemed apparently blank.
 A more subtle method of using
invisible inks was common during
WWII. The simplest organic
compounds, such as lemon juice, milk,
or urine, all of which turn dark when
held over a flame were used. Modern
invisible inks fluoresce under
ultraviolet light and are used as anti-
counterfeit devices.
 With the advent of photography,
microfilm was created as a way to store
a large amount of information in a very
small space. In both world wars, the
Germans used "microdots" to hide
information, a technique which J.
Edgar Hoover called "the enemy's
masterpiece of espionage." A secret
message was photographed, reduced
to the size of a printed period, and then
pasted into an innocuous cover
message, magazine, or newspaper.
All of these approaches to steganography have
one thing in common -- they hide the secret
message in the physical object which is sent.
The cover message is merely a distraction, and
could be anything. Of the innumerable
variations on this theme, none will work for
Steganography -
The Dark Cousin of Cryptography
Aishwariya Chakrabarty
B.Tech - 2015
40

41. 41
electronic communications because only the
pure information of the cover message is
transmitted. Nevertheless, there is plenty of
room to hide secret information in a not-so-
secret message. It just takes ingenuity.
A good steganographic technique should
provide secrecy even if everyone knows it's
being used.
The key innovation in recent years was to
choose an innocent looking cover that
contains plenty of random information, called
white noise. The secret message replaces the
white noise, and if done properly it will appear
to be as random as the noise was.
The most popular methods use digitized
photographs, so let's explore these techniques
in some depth.
Digitized photographs and video also harbour
plenty of white noise. A digitized photograph
is stored as an array of pixels. Each pixel
typically has three numbers associated with it,
one each for red, green, and blue intensities,
and these values often range from 0-255. Each
number is stored as eight bits (zeros and ones),
with a one worth 128 in the most significant bit
(on the left), then 64, 32, 16, 8, 4, 2, and a one
in the least significant bit (on the right) worth
just 1.
A difference of one or two in the intensities is
imperceptible, and, in fact, a digitized picture
can still look good if the least significant four
bits of intensity are altered -- a change of up to
16 in the colour’s value. This gives plenty of
space to hide a secret message. Text is usually
stored with 8 bits per letter, so we could hide
1.5 letters in each pixel of the cover photo. A
640x480 pixel image, the size of a small
computer monitor, can hold over 400,000
characters. That's a whole novel hidden in one
modest photo!

42. 42
Hiding a secret photo in a cover picture is even
easier. Line them up, pixel by pixel. Take the
important four bits of each colour value for
each pixel in the secret photo and replace the
unimportant four bits in the cover photo. The
cover photo won't change much, you won't
lose much of the secret photo, but to an
untrained eye you're sending a completely
innocuous picture.
Unfortunately, anyone who cares to find your
hidden image probably has a trained eye. The
intensity values in the original cover image
were white noise, i.e. random. The new values
are strongly patterned, because they represent
significant information of the secret image.
This is the sort of change which is easily
detectable by statistics. So the final trick to
good steganography is to make the message
look random before hiding it.
One solution is simply to encode the message
before hiding it. Using a good code, the coded
message will appear just as random as the
picture data it is replacing. Another approach
is to spread the hidden information randomly
over the photo. "Pseudo-random number"
generators take a starting value, called a seed,
and produce a string of numbers which appear
random. Descrambling the photo requires
knowing the seed that started the pseudo-
random number generator.
All of this sounds fairly nefarious, and in fact
the obvious uses of steganography are for
things like espionage. After the events of
September 11, 2001, there was immediate
concern voiced regarding the possible use of
steganography by the Al Queda network.
Initially , there were reports that hidden
messages might be located in images located
on XXX rated web sites. Following up on this,
a group at the University of Michigan began
scanning images located on various sites such
as eBay auctions. After scanning over two
millions images, the researchers reported back
that they had not found any suspect images.
The article in USA Today didn’t indicate if the
researchers actually scanned any images
located on XXX web sites.
Beyond the concerns of hidden messages in
images, there has been additional concern
voiced regarding the television broadcast of
bin Laden. Remembering that steganography
is hardly the sole property of digital
technology, there is the possibility that there
could have been hidden messages in the audio
portion of the broadcasts, or even in the
background of the televised images.
However, there are a number of peaceful
applications also. For e.g., to use
steganography like a watermark, to protect
copyright on information, in CDs, files, etc.
Even biological data, stored on DNA, may be a
candidate for hidden messages. Three New
York researchers successfully hid a secret
message in a DNA sequence and sent it across
the country. Sound like science fiction? A
secret message in DNA provided Star Trek's
explanation for the dubious fact that all aliens
seem to be humans in prosthetic makeup!
There is always a dilemma in steganography, a
dilemma that empowers it. You never know if
a message is hidden. You can search and
search, but when you've found nothing you can
only conclude: Maybe I didn't look hard
enough, but maybe there is nothing to find.

43. Ahana Ghosh, B.Tech. 2015
Internship opportunity at Ericsson was a
dream come true for me. The entire matter
was unexpected and I got this opportunity just
because of my college. When I
was wandering here and there
to find some good exposures
for an internship which would
help me to attach some practical knowledge to
my academic learning, this fighting chance
knocked on my door. I got a mail from our
college that Ericsson has offered our college
students a chance to be a part of their
internship programme. They mentioned
several bars and criterions in terms of
academic percentages and performances and
interested students holding those or above
mailed their respective resumes. The final
shortlisting was done by the company itself on
the basis of those percentages and they
informed the names of the selected candidates
by dropping a mail. Among the two names
mentioned in that mail, one read mine and I
was extremely happy to get the break for the
paid summer internship programme at such a
brilliant place.
The internship programme started at the
Kolkata office of Ericsson from 15th of June,
2013. There were other interns from other
colleges. I was the only student from ECE
background there and hence got the chance to
work in their communication domain which
they mainly excel in. It was an extremely
pleasing experience to work there and the
work culture was excellent. My project was on
automation of a part of the communication
system and span was for one and a half
months. My project named “Automation of
Voice and Data Capacity Planning based on
Present and Forecasted Traffic”. My job was to
write a programme using Excel VBA that
would take in its input the different working
datasheets and calculate automatically the
other parameters for mobile communication
and forecast the traffic on the line that will
help to take decision on augmentation or de-
augmentation of resources for proper
communication. I got a very helpful
environment. It ended on time with the
submission of the project report and a PPT
presentation on my part. I left with a glad and
contented mind. We also got stipend as we
were paid interns. After seven days we got our
certificates from the office which ended the
programme.The whole journey was indeed
very exciting and enriching for me and my
much awaited day came true.
Riya Seth, B.Tech. 2016
I am two months into my internship, I figure
it’s about time for a reflection on my
internship as a whole this far: how this
Gaining work-experience in College : INTERNSHIPS
Landing a job in this tough economy is no easy feat—especially for college students and recent grads.
They often spend weeks scouring online job boards, polishing cover letters and blasting out résumés to
no avail. But what they really need to do is get an internship. It turns out that may be the easiest way to
secure a full-time gig, as 69% of companies with 100 or more employees offered full-time jobs to their
interns in 2014, according to a new survey.
43

44. 44
experience has influenced my future and how
my university schooling prior to my internship
has helped me.
First and foremost this
experience has affected me in
ways I did not foresee. As with
most experiences in life
things do not usually go as planned, but always
end up leaving you with something good and
worth-while (and often better than what you
had anticipated).
I had been trying for a good research
internship in the field of quantum Information
since I was in second year. I applied for the
internship to IQC (the most famous group of
quantum computation), CQT (Singapore) and
in India IISER’s, RRI and many other places.
But each and everyone refused me since I am
from electronics engineering background, not
from physics or engineering physics. This was
completely discouraging. But I did not give up
rather I started to study more about this field.
Then again I applied for internships this year
and this time I personally contacted with many
professors and tried to convince them that I
am also strong in quantum mechanics like
other physics students though I am not from
pure physics background. Finally Dr. Ujjwal
Sen, Quantum Information and Computing
group, HRI, responded me and accepted my
letter and then suddenly I became full of
confidence about myself.
My experience in HRI (Harish-Chandra
Research Institute) was a life-time experience.
I was treated like a chief-guest there, as if they
were very happy to get a visitor like me. The
population is not so much there, so it took little
time to be a part of the HRI family. I got a new
family there, did not feel being far from my
family.
For the first month I was taught the most
required fundamental subjects by the research
scholars and other faculties. The next month I
was assigned a new project to complete. It was
a great opportunity for me to get a new project
in a new field.
At the completion of my visitor-ship I was
awarded by some memorandum. I would love
to go to HRI again if I can get another
opportunity in future. I did not expect that
such a research internship can be as full of fun
and enjoyments as I experienced there. Now I
am missing those precious days in HRI,
especially those pure veg meals (I do not know
how I spent those months without non-veg),
the peacocks, the hedgehogs, the dark forest
and the pure nature besides the Ganges-
Yamuna Sangam.
Binayak Ghosh, B.Tech. 2015
‘Internship’ and 'Training' - these two are the
buzz words, especially among
the second year and third year
engineering students, as an
internship or a training from
a reputed institution or company can enhance
the weight of one's profile by a huge margin
and put them on the front foot during the
placement interviews. Not overly interested in
professional traineeships, I went looking for a
research intern position at some of the reputed
universities and laboratories of the country.
With a mind to pursue further studies and
research in the future, I had mailed several
professors in some of the universities for a
chance to work in their lab during the summer.
I was quite surprised and elated when Prof. Dr.

45. 45
Jayanta Mukhopadhyay, at the Computer
Science Department of the esteemed I.I.T.
Kharagpur, expressed his desire to offer me a
research intern position at his lab.
I arrived at the IIT, a day after my 6th semester
exam ended and I was provided
accommodation at the LBS Hall of Residence,
the newest and biggest hostel in the campus. It
was a 3-bed room, with a balcony that
overlooked the railway tracks outside the
campus. My professor assigned me to work as
a part of a research group dedicated to
construct a semi-humanoid robot, this project
was also sponsored by the MHRD, Govt. of
India and they provided me with a certain
amount of stipend at the end of my internship.
My responsibilities were to design the core
structure of the holonomic robot, using a
micro-controller based development platform.
It was there, that I was first introduced to the
problem of autonomous robotic navigation
and I learnt and implemented 2D SLAM
algorithm which utilizes 2D scan data and
odometry information in an unknown
environment, to create a map with estimates
of obstacle positions.
I was assigned a particular desk in the lab as
well as given a free pass to use all equipment
and components I required. My lab partners
where all PhD scholars doing research in
various fields. It was really an eye-opening
experience for me, as this was the first time I
had the opportunity to work in such a proper
research setup. My colleagues were some of
the best and most friendly people, I have met
till today. In spite of working in such serious
and difficult fields of research, their jokes and
friendly banter always ensured the prevalence
of a jovial atmosphere in the lab. They were
always there, ready to help in any way that I
may want. But, they were also extremely
passionate about their research. Some of them
used to sleep, eat and live in the research labs
itself.
Being a student from IEM, the incredibly wide
expanse of the IIT campus, shrouded in lush
greenery, weaved an enchanting picture that I
will forever cherish. The rolling football fields,
the Gnan Ghosh stadium, the serene roads, the
bicycle tracks, covered with fallen leaves from
the trees, after a rainy afternoon- all these
added to the charm of the institution. The view
of the rolling expansive fields together with the
sight of the chugging train on the railway
tracks, as visible from my hostel room balcony,
was a sight to behold!! Some of the best
moments that I will never forget, were the late
night World Cup matches that we used to
watch together in the hostel common room. It
was a great feeling with everybody huddled
together before the big LCD screen of the TV
and cheering together for every goal or cursing
after every tackle or missed opportunity.
My internship at the IIT provided me with an
amazing experience that I could not have
envisaged at my own college. The research
experience I gained, helped me in
understanding the working of a research
setup, and also proved critical for providing
me further research opportunities in the
future. I met various students, researchers,
scientists and professors from not only India,
but from all over the world. I realized that
those two months were the best moments of
my entire four years in college, as I had an
awesome time, not only from an academic
point of view but also had unbelievable fun
with some great friends.

46. Bluetooth has been in business for a quite a
long time. From phones to iPods to speakers
and mini-gadgets, communication is never
complete without this technology. And now,
we have entire buildings under the grip of
Bluetooth, every appliance, from huge motors
and office-scale air conditioning units, to fans
and bulbs, everything can be controlled at the
effort of simply tapping your phone! This
technology has been successfully implemented
as a prototype at ECE department, IEM.
The scale of homes, offices, and level of
workload of modern professionals, combined
together, make it difficult to manually to
switch on/off appliances as and when we need
them. There is persistent annoyance about
going up and down an office, or shift from
one’s work to do such trivial tasks, yet is
unavoidable. Moreover, if take into account
the judicious usage of energy, and its
importance in the modern world, optimized
usage of electrical appliances is a must. Just
consider this example, a busy professional
leaves the room with the AC on, for an hour.
Considering the AC to be working at 2.5kW,
the estimated energy wastage is: 9 mega
joules! It is important how we deal with energy
crisis in the modern times, without
compromising with our comforts.
We are in requirement of an integrated
system, which will operate throughout the
rooms of our home or office, connect all
appliances, and make it possible to switch
them readily when in need. Another important
feature of this system will be to sense when the
user is out of range. In that case, apart from
certain pre-selected appliances, all other
appliances will be switched off. If such
common and emerging problems are catered
to, it won’t be unwise to hope that this
technology will find a niche in the market quite
soon.
Description
At the heart of the entire Bluetooth Controlled
Switchless Home lies the Bluetooth modem.
There are large variety of ICs manufactured
which support communication by Bluetooth
protocols. In our project, we have used the
HC05 chipset, along with UART
communication support and inbuilt
microstrip antenna. Bluetooth
communication requires setting up of a
2.4GHz radio frequency channel, which acts as
carrier. Precisely, the Bluetooth bandwidth
extends from 2400 MHz to 2483.5 MHz, with
2 MHz lower and 3.5 MHz upper guard band,
and 79 channels, each of 1 MHz bandwidth.
Figure 1: HC05 Bluetooth Modem
Bluetooth Controlled
Switchless Home
Susmit Bhattacharya
B.Tech - 2016
46

47. 47
Bluetooth 4.0 however contains 40 channels
@ 2MHz each.
The communication mode of Bluetooth
follows the master-slave structure where each
master can simultaneously communicate with
7 slaves. Data is sent in packet protocol, via the
RF channel using the DQPSK (differential
quadrature phase shift keying), which allows
for high bit rate. Security is maintained from
the fact that for a particular connection, the
frequency channels are always varying with
rates at about 1600 hops/sec. A pre-shared
pseudo-random sequence is followed in
shifting from channel to channel. Thus we see,
though the communication bandwidth is in
excess of 80MHz, each hop is actually 1 MHz,
thereby allowing for considerably low noise
interference. (Note: thermal noise is
proportional to bandwidth.)
Knowing the basic communication
mechanism of Bluetooth, we now come to the
specifics of our project. We have 3 basic
components in our inventory: a Bluetooth
modem, a microcontroller, and a smartphone
app. The interaction of these primary
components creates the framework necessary
for our project. We’ll now describe each
component in detail.
We have used a customized Android app for
this purpose. Describing the app in detail is
quite cumbersome, so we stick to the
wireframe structure. It basically consists of an
interactive GUI containing ON/OFF touch
buttons for each appliances. According to the
state of each button, the app sends a unique
code to the Bluetooth modem. It also pings at
regular intervals (30 seconds in our project) to
indicate connectivity. In our future
developments,
we intend to
design a room-
mapping GUI to
indicate the
appliances
present in
various rooms.
We had
discussed in detail about Bluetooth
communication methodologies earlier. A
Bluetooth modem is used to receive the data
from the smartphone, and forward it to the
microcontroller, for decision-making and
switching procedure.
A microcontroller, by definition, is akin to a
computer on a single chip. A good variety of
microcontrollers are available these days. We
have chosen to use the ATmega328, on an
Arduino platform (Arduino Uno). Arduino
programming is quite simple to code and
upload to the microcontroller. The task of the
microcontroller is to switch the various
electrical devices to their requisite on/off
states, as per the information received from
the Bluetooth modem.
The communication mechanism consists of
the phone app keeping constant track of the
on/off states of various devices. Any change of
state is reported to the microcontroller (via the
Bluetooth module) using a designated code.
The microcontroller detects these changes and
accordingly, modifies the state of the
connected electrical device. The automatic
switch-off mechanism is also an innovation.
Whenever the user walks out with his phone,
and reaches beyond a certain threshold, the
short-range feature of Bluetooth comes to

48. 48
play. Periodic pings are no longer sent to the
microcontroller, and when the
microcontroller detects the absence of pings
over a given duration (30 seconds in our
prototype), it switches off all appliances
connected to it.
Many readers must be wondering, how the
microcontroller, which works at +5V DC,
manages to switch multiple 230V AC systems.
The answer is a relay. It can be solid state or
electromechanical. We have used the latter
type to allow the switching between various
devices.
It takes in a small current to activate an
electromagnet, whose movement determines
the switching contacts of the devices.
We therefore have discussed the working
mechanism of our project. Interested parties
are welcome to communicate with us to view
our prototype and allow for possible
commercial success. We can conclude with the
assertion that though the switching of
appliances may seem a trivial task, given our
present world of high-workload, low manual
assistance, and efficient energy expenditure
requirements, our low cost home automation
prototype can provide a mighty solution and
bring about considerable ease of living.
Bluetooth is creating endless possibilities for
the smart home both in energy management
and home automation. Bluetooth smart home
devices in smart home is forecast to reach over
114 million in 2018, making it one of the top
wireless sensor network technologies around.
****
SOLUTION TO CROSSWORD ON PAGE 19

49. While travelling from Gariahat to Ruby in a
car, I observed that at each and every traffic
signal the car had to wait for quite some time.
There was no coordination between the
consecutive signals. I found that flow of
vehicles was not good. If a car had to stop in a
signal, after that it had to stop again in the next
signal. One more thing I noticed that the
counter never showed proper waiting time. So
what is the benefit of this kind of signalling
system?
In a city like Kolkata it’s impossible to avoid
traffic queuing entirely, as the figure is pretty
large. What can be done is we can control the
flow and make a semi-automated
synchronized traffic signalling system to
handle it efficiently. The net like structure of
the roads in a city can be thought as a matrix.
Several rows and columns are there. The
whole city can be divided into zones. Intra-
zone traffic would be controlled following
predefined algorithm. And master control
station would control the inter-zone traffic.
Say rows are considered as straight roads and
columns as cross roads. Within a zone all the
signals for straight roads will be on
simultaneously. And when the straight roads
flow stops all the cross roads will be enabled
simultaneously. Inter-zone regions have to be
selected such that long queue of vehicles can
wait before entering the next zone. CCTV will
be mounted for monitoring the number of
vehicles by the master station. At the entry of
each zone when the signal is enabled it will
automatically enable previous road’s exit
provided the other timing constraints are met
like cross road enable time. Main station will
monitor the traffic at the inter-zone region and
accordingly it will enable signals for a
particular zone. All the on/off counters will be
programmable through master station. Intra-
zone communication will mainly be through
PLCC(Power Line Communication Control),
short range transmitter and receiver or it can
be Wi-Fi. Main control station will have
broadband access as it has to send CCTV data
also. Master control station can control the
operation of the zone control stations which in
turn can control individual zones too.
As there will be no person fiddling with the
counters by keeping it stable at zero for quite
long or starting the counter afresh after it has
reached zero, it will show the exact waiting
time So the drivers would come to know when
they have to start the vehicle. This will
immensely save fuel wastage and decrease the
irritation of the drivers as well. Maximum total
commuting time can be determined before
starting a journey. A patient in an ambulance
stuck in a jam would be able to increase the
counter of hope with the every tick tock he
listens to!
Optimistic View of Efficient &
Automated Traffic Control System
Pallabi Sinha
B.Tech - 2015
49

50. The fourth generation of mobile phone
technology builds on what 3G offers by
supposedly being much faster.
Bharti Airtel launched India's first 4G service,
using TD-LTE technology, in Kolkata on 10
April 2012. On June 2013, prior to the official
launch in Kolkata, a group consisting of China
Mobile, Bharti Airtel and SoftBank Mobile
came together, called Global TD-LTE
Initiative (GTI) in Barcelona, Spain and they
signed the commitment towards TD-LTE
standards for the Asian region. It must be
noted that Bharti Airtel's 4G network does not
support mainstream 4G phones such as
Samsung Galaxy Note 3, Samsung Galaxy S4
and others.
Bharti Airtel 4G services are available in
Kolkata, Bangalore, Pune, Hyderabad,
Visakhapatnam and Chandigarh region. Since
May 2015, Airtel had also partnered with
Samsung India to introduce 4G services in
Chennai, on a trial basis. They launched 4G on
mobiles in Bangalore, thus becoming the first
in India to offer such a service on 14th Feb,
2014. In July 2014, they expanded 4G services
to many cities in Punjab. Until July 2014,
Customers in these cities access 4G services
through dongles and wi-fi modems on Apple
iPhone 5S and 5C, XOLO LT 900 and LG G2
(model D802T).
RIL is launching 4G services through its
subsidiary, Jio Infocomm. RIL 4G services are
currently available only in Jamnagar, where it
is testing the new TD-LTE technology.
Reliance's 4G rollout is planned to start in
Delhi, Mumbai and Kolkata and expand to
cover 700 cities, including 100 high-priority
markets in 2015.
Aircel in July 2014, launched 4G in four circles
Andhra Pradesh, Assam, Bihar and Odisha.
Tikona Digital Networks holds broadband
wireless access spectrum in the 2300 MHz
band and is waiting for the appropriate time
and maturity of the 4G ecosystem before
making a foray into the space. Tikona holds 4G
spectrum licenses in five circles in northwest
India, covering Gujarat, Rajasthan, Uttar
Pradesh (East and West) and Himachal
Pradesh.
Many people don’t even receive decent 3G
signals, so who cares about 4G, you may ask.
Well, the technology is now available and that
is reason enough to care. Anyone buying a
high-end smartphone such as an iPhone 5S or
the new HTC One M8 will have the option to
upgrade to 4G. But is it worth the extra money,
The Fourth Protocol Sounak Lahiri
B.Tech - 2016
50

51. 51
or is Wi-Fi connectivity and 3G good enough
for now?
The touted benefits of 4G include improved
download and upload speeds, reduced latency
– which means a device connected to a 4G
mobile network gets a quicker response to a
request than the same device connected to 3G
– and crystal-clear voice calls (due later this
year).
Why 4G?
Standard 4G – or 4G LTE – is around seven to
eight times faster than 3G, offering theoretical
speeds of up to 150Mbps. That translates as
maximum potential speeds of around 80Mbps
in the real world. For example, you can
download a 2GB HD film in three minutes, 20
seconds on a standard 4G mobile network;
that would take over 25 minutes on a standard
3G network.
Improved latency times, reduced from 120
milliseconds (3G) to 60 milliseconds (4G), can
also make a big difference when playing online
games and streaming video.
Voice over LTE (VoLTE) is another feature
that is exclusive to 4G, although it is not yet
available in the UK. VoLTE is similar to Voice
over Internet Protocol (VoIP) as used with
voice apps such as Skype.
Effectively, VoLTE rides on the back of the 4G
network and will bring crystal-clear voice calls
and video chat to your 4G mobile phone. EE
plans to trial the service at some point this
year, so it hopefully won’t be long before you
can experience high-quality calls over 4G.
When to go for 4G?
In 2015, almost everyone should have a 4G
phone. Verizon now has nationwide 4G LTE
coverage. T-Mobile and MetroPCS have
nationwide HSPA+ 42 and growing LTE
networks. AT&T has broad LTE coverage.
Sprint is still building out LTE, but by next
year the carrier aims to be comprehensive.
If you like to surf the Web and especially
stream video, 4G can be heaven. If you connect
a laptop to your mobile link, 4G makes a huge
difference. In general, anything involving
transferring large amounts of data gets a big
boost from 4G. Watch out for the data limits
on your service plan, though; it's easy to use up
a lot of data very quickly with 4G.
If you have a 3G phone and you've been
frustrated with slow data, 4G may be the
solution. 4G won't solve any dropped call
problems, though, as all calls will be made over
older networks until carriers switch to voice-
over-LTE during the next few years.
Finally, if you want to future-proof yourself,
get a 4G phone. 4G coverage is only going to
get better, and that's where the carriers are
spending most of their money right now. You
can assume that all 4G phones also support
your carrier's 3G and 2G networks as well.
“I know that I am intelligent, because I know that I know nothing.” - Socrates

52. 24th September, 5000. 15:45:00.
Site 647C, Subcontinental Peninsula, Gurgaon Ruins.
"There! I found something! It's a strange
colour. The colour of babies."
"It looks like a tiny human figure."
"A very unhealthy human figure. What is it?
Some kind of God figurine?"
"What is God?"
"They used to believe everything was created
by some God. Supernatural beings."
"Possible. Look there's more."
"An entire family of figurines! The small ones
look healthier. Why are there no male
figures?"
"Maybe they didn't worship any males?"
"Let's take this now and wrap it up for today."
"Stop digging guys! We need to get back to the
'ship. The sun is setting."
24th September, 5000. 17:00:00.
Asian Research Aero ship, Subcontinental Peninsula,
hovering 13000m above Sea.
"What could these mean?"
"Here's your dinner. Will 2 pills be enough?
It's mashed potatoes and bread tonight."
"I'm not very hungry. I'm confused."
"Why?"
"That's the question. Why? Why would they
worship disproportionate women? Why were
there no men? Was this what they looked
like?"
"Maybe they didn't need men?"
"Don't be ridiculous! If they didn't need men,
where did the men come from? Did they grow
Y chromosomes? Wait. That might be
possible."
"But then there are male children figures."
"We need to go and check the site again
tomorrow. Switch me off, will you? I need
some charge."
"Goodnight. I'm going to grow a girl. And
maybe watch some fish after that."
25th September, 5000. 10:15:00.
Site 647C, Subcontinental Peninsula, Gurgaon Ruins.
"Let's start the digging from the same place."
5000 A.D.
Agomoni Sarkar
B.Tech - 2015
52