Research Issues on WSN

Research issues in WSN
&
How to do Doctoral research
Dr.A.Kathirvel, Professor and Head, Dept of IT
Anand Institute of Higher Technology, Chennai

Wireless Sensor Networks
(Phase – I)

3
Outline
Introduction
Wireless Sensor Networks
Research Issues in WSN
Conclusion

WIRELESS SENSOR NETWORKS
• Wireless Sensor Networks (WSN) are
used in a variety of fields:
• military,
• healthcare,
• environmental,
• biological,
• home and
• other commercial applications.
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• There has been a huge advancement in
the fields of embedded computer and
sensor technology, Wireless Sensor
Networks.
• These Networks (WSN) are composed of
several thousands of sensor nodes.
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• These nodes are capable of –
• sensing,
• actuating, and
• Relaying the collected information.
• They have made remarkable impact
everywhere.
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• A sensor network is capable of sensing,
processing and communicating.
• This helps the base station or command
node to observe and react according to
the condition in a particular environment
(physical, battle field, biological).
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• Sensor network protocols have a unique
self-organizing capability.
• Another interesting feature of WSNs is
that the sensor nodes cooperate with each
other.
• Sensor nodes have an in-built processor,
using which raw data are processed
before transmission.
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• These features facilitate wide range of
applications of WSNs ranging from
• biomedical,
• environmental,
• military,
• event detection and
• vehicular telemetric.
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RESEARCH ISSUES
• Current research topics in Wireless sensor
Networks ARE :
• Power Management
• Localisation
• Routing
• Deployment Technique
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Power Management
• A sensor network is composed of a large
number of sensor nodes.
• These are densely deployed either inside
the environment or close to it.
• The position of sensor nodes need not be
engineered or predetermined.
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Power Management
• This allows random deployment in
inaccessible terrains or hazardous
environments.
• Some of the most important application
areas of sensor networks include military,
natural calamities, health, and home.
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ENERGY Management
• When compared to traditional ad hoc
networks, the most noticeable point about
sensor networks is that, they are limited in
power, computational capacities, and
memory.
• Hence optimizing the energy consumption
in wireless sensor networks is the most
important performance objective.
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ENERGY Management
• This challenge necessitates energy-
awareness at all layers of networking
protocol stack.
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ENERGY Management
• The issues related to physical and link layers
are generally common for all kind of sensor
applications.
• Therefore the research on these areas has
been focused on system-level power
awareness such as dynamic voltage scaling,
radio communication hardware, low duty
cycle issues, system partitioning, energy
aware MAC protocols.
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ENERGY Management
• At the network layer, the main aim is to
find ways for energy efficient route setup
and reliable relaying of data from the
sensor nodes to the sink so that the
lifetime of the network is maximized.
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Localization
• A fundamental problem in designing
sensor network is localization –
determining the location of sensors.
• Location information is used to detect and
record events, or to route packets using
geometric-aware routing.
18

Localization
• Manual configuration of locations is not
feasible for – large-scale networks or
networks where sensors may move.
• Providing each sensor with localization
hardware (e.g., GPS) is expensive in
terms of cost and energy consumption.
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Localization
• A more reasonable solution to the
localization problem is to allow
some nodes (called seeds) to have their
location information at all times, and allow
other nodes to infer their locations by
exchanging information with seeds.
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Routing
• Routing in sensor networks is very
challenging!
• First of all, it is not possible to build a
global addressing scheme for the
deployment of sheer number of sensor
nodes. Therefore, classical IP-based
protocols cannot be applied to sensor
networks!
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Routing
• Second, in contrary to typical
communication networks almost all
applications of sensor networks require
the flow of sensed data from multiple
regions (sources) to a particular sink.
• Third, generated data traffic has significant
redundancy.Such redundancy needs to be
exploited by the routing protocols to
improve energy and bandwidth utilization.
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Routing
• Fourth, sensor nodes are tightly
constrained in terms of transmission
power, on-board energy, processing
capacity and storage.
• Thus require careful resource
management.
23

Routing
• There are three main components in a
sensor network. These are the
sensor nodes,
sink and
 monitored events.
• Aside from the very few setups that utilize
mobile sensors, most of the network
architectures assume that sensor nodes
are stationary.
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Routing
• On the other hand, supporting the mobility
of sinks or cluster-heads (gateways) is
sometimes deemed necessary.
• Routing messages from or to moving
nodes is more challenging !
• This is because route stability becomes an
important optimization factor, in addition to
energy, bandwidth etc.
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Routing
• Efforts are being made to design routing
protocols for WSN which are energy
efficient.
• The next slide lists some energy efficient
routing protocols proposed for WSN.
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Data-centric protocols
• In many applications of sensor networks, it
is not feasible to assign global identifiers
to each node due to the sheer number of
nodes deployed.
• Such lack of global identification along
with random deployment of sensor nodes
make it hard to select a specific set of
sensor nodes to be queried.
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• Therefore, data is usually transmitted from
every sensor node within the deployment
region with significant redundancy.
• This is very inefficient in terms of
energyconsumption, routing protocols that
will be able to select a set of sensor nodes
and utilize data aggregation during the
relaying of data have been considered.
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• Flooding and gossiping
• Sensor protocols for information via negotiation
• Directed Diffusion
• Energy-aware routing
• Rumor routing
• Gradient-based routing
• CADR
• COUGAR
• ACQUIRE
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• Flooding and Gossiping: Flooding and
gossiping are two classical mechanisms to
relay data in sensor networks without the
need for any routing algorithms and
topology maintenance.
• In flooding, each sensor receiving a data
packet broadcasts it to all of its neighbors
and this process continues until the packet
arrives at the destination or
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• The maximum number of hops for the
packet is reached. On the other hand,
gossiping is a slightly enhanced version of
flooding.
• Here the receiving node sends the packet
to a randomly selected neighbor, which
picks another random neighbor to forward
the packet to and so on.
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• CADR: Constrained anisotropic diffusion
routing (CADR) is a protocol, which strives
to be a general form of Directed Diffusion.
• Two techniques namely information-driven
sensor querying (IDSQ) and constrained
anisotropic diffusion routing (CADR) are
proposed
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• COUGAR proposes an architecture for the
sensor database system where sensor
nodes select a leader node to perform
aggregation and transmit the data to the
gateway (sink)
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• ACQUIRE: A fairly new data-centric
mechanism for querying sensor networks
is ACtive Query forwarding In sensoR
nEtworks (ACQUIRE). The approach
views the sensor network as a distributed
database and is well-suited for complex
Queries which consist of several sub
queries.
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Hierarchical protocols
• LEACH
• PEGASIS and Hierarchical- PEGASIS
• TEEN and APTEEN
• Energy-aware routing for cluster-based
sensor networks
• Self-organizing protocol
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Location-based protocols
• MECN and SMECN
• GAF
• GEAR
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Network flow and QoS aware
protocols
• Maximum lifetime energy routing
• Maximum lifetime data gathering
• Minimum cost forwarding
• SAR
• Energy-aware QoS routing protocol
• SPEED
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Technological contributions..
• The key contributions in the last decade are
related to
• distributed detection and information fusion;
• Routing and Clustering;
• Link Scheduling, Coverage
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Technological contributions..
• Localization of sensor nodes,
• Time synchronization,
• Multimodal data fusion,
• Cross layer optimization,
• Network coding, and
• Low power electronics design.
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Conclusion
• The area of WSN is thriving and every day
new ideas are emerging. A strong testimony
to this is the recent report on Smart Sensor
Networks.
• Another area which needs a tremendous
impetus to make sure that WSN thrives is
sensor technology.
• Nevertheless, the area of routing in WSN is
wide open.
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Write an Research Paper
(Phase – II)

Outline
Introduction
Step-by-step instruction to write an paper
Plagiarism
Conclusion

Why do you need to learn how to
write a research paper?
Because in high school and college you will be
asked to write many research papers, and you
need to learn what goes into writing a successful
paper.
This PowerPoint presentation will give you step-
by-step directions on how most high school and
college teachers/professors expect you to write a
basic research paper.

Learning Targets
You will learn how to choose a topic.
 Depends on the length of your paper, choose a narrower topic
for a short paper, and a broader topic for a longer paper.
You will learn how to write a thesis statement.
 One sentence that summarizes what your paper is about, or
what you are trying to prove. (Last sentence of your
introduction)
You will learn how to explain the differences between a primary and
secondary source.
You will be able to understand the difference between plagiarism and
acceptable paraphrasing.
You will be able to learn how to edit your paper, and make necessary
changes.
You will learn how to use “parenthetical notations.”

Step-by-step instructions on how to
write a research paper
The topic
The thesis or introductory statement
The outline
Selecting and analyzing sources & selecting websites
Compiling information on index cards or in Microsoft Word
Plagiarizing, paraphrasing, and direct quoting
Bibliography & the proper format
Proofreading & the cover page
Rubric

You should also have:
1. A note-taking handout.
As we go through the
assignment, take notes,
or write down any
questions you have
2.A sample outline
3.Examples of plagiarizing
v. paraphrasing
I’ve just
stolen
other
author’s
work!
“Plagiarizer”

Overview:
Requirements (What you need for your paper) √
Topic Questions (What you need to put into your paper) √
Choices (The disasters you will research) √
How to write your research paper: Follow these
instructions step-by-step!
1. Your outline should be written before you start your paper. It organizes
your thoughts and creates a plan so you know how your paper will look.
2. Your introduction or thesis statement tells the audience what you will
explain in your paper. It will let the audience know what to expect from
reading your paper.
3. You are required to use a minimum of three sources. You must have at
least one book , one website, and one encyclopedia (online or book
format) *No wikipedia.org; mtv.com; or youtube.com unless by permission of Mrs. Nuzzo

As you research the answers to the topic questions
you can use the information two ways:
1. If it is from a non-computer source, you can use index
cards to copy the information needed, or can type the
information on a documents in Microsoft Word.
2. Make sure you have a heading on the index card or word
document so you know the topic or question you are
answering with this information
3. Always SAVE any information you type into Microsoft
Word! Make sure you save it to your number…NOT to the
computer you are working on. SAVE information
frequently!!!

Plagiarism v. Paraphrasing Samples
Direct quote from research:
“Japan’s beautiful Mount Fuji last erupted in 1707 and is now classified as dormant.
Dormant volcanoes show no signs of activity, but they may erupt in the future.”
Non-plagiarized paraphrase:
Mount Fuji, the highest mountain in Japan, is actually a dormant volcano. Dormant means
that it is not active. The last time Mount Fuji erupted was in 1707, and there is always the
possibility of a future eruption.
Direct quote from research:
“Three weeks after Katrina, warnings of the arrival of Hurricane Rita sent residents of cities
such as Houston, Texas, rushing to evacuate, fearing for their lives. Fortunately, Hurricane
Rita turned out to be much less severe than Katrina. However, mass evacuations like this
bring hazards of their own, as panicking drivers may cause accidents on the jammed roads.”
Non-plagiarized paraphrase:
Shortly after Hurricane Katrina devastated the city of Houston, Texas, a warning for a new
hurricane named Rita was broadcast, which caused many people to panic and flee the city.
However, the mass departure of people leaving Houston at the same time could have caused
many car accidents, even though the hurricane turned out to be not as dangerous as Katrina.

“How do I QUOTE an author?”
• If you quote an author, insert
“quotation marks” around the text
you are using.
• At the end of the quotation,
parenthetical notations are
needed.
• Simply write the quote and then
put the author’s name and page
number:
• (Williamson, 148)
• You will cite the entire source
when you get to the bibliography
page of your paper.
“I WILL NOT
PLAGIARIZE
I WILL PUT
MY PAPER
INTO MY OWN
WORDS.”

Bibliography or Works Cited Page
1. At the end of your paper you will include a bibliography or works
cited page.
2. This gives the authors of your sources credit for their work.
3. In your packet you will find sample bibliography entries for various
sources.
4. If you have any questions you can refer to:
http://www.aresearchguide.com/12biblio.html or the
information in the packet.
5. Sources should be in alphabetical order and double spaced.
6. You can also use the following website to input your source
information for your bibliography or works cited page:
www.noodletools.com/quickcite/

Works Cited
"Battery." Encyclopedia Britannica. 1990.
"Best Batteries." Consumer Reports Magazine 32 Dec. 1994: 71-72.
Booth, Steven A. "High-Drain Alkaline AA-Batteries." Popular Electronics 62 Jan. 1999:
58.
Brain, Marshall. "How Batteries Work." howstuffworks. 1 Aug. 2006
<http://home.howstuffworks.com/battery.htm>.
"Cells and Batteries." The DK Science Encyclopedia. 1993.
Dell, R. M., and D. A. J. Rand. Understanding Batteries. Cambridge, UK: The Royal
Society of Chemistry, 2001.
"Learning Center." Energizer. Eveready Battery Company, Inc. 1 Aug. 2006
<http://www.energizer.com/learning/default.asp>.
"Learning Centre." Duracell. The Gillette Company. 31 July 2006
<http://www.duracell.com/au/main/pages/learning-centre-what-is-a-battery.asp>.

Proofread, Proofread, & Proofread!!!
1. Are all words spelled correctly? (Use a paper or online dictionary is unsure!)
2. Did I capitalize the beginning of each sentence and all proper nouns?
3. Did I punctuate correctly?
4. Do I use grammar correctly?
5. Did I answer all of the topic questions, and fulfill all of the requirements on my
rubric.
6. Did I include an introduction and conclusion?
7. Did I type the paper using the correct font type, size, line spacing and margin
requirements?
8. Did I paraphrase all content?
9. Did I use parenthetical notations for quotes?
10. Do my sentences make sense when read aloud?
11. Have I had my paper peer edited?
12. Does my paper flow well?
13. Did I include a bibliography page?

Conclusion
• The conclusion of a research paper needs to
summarize the content and purpose of the paper
without seeming too wooden or dry. Every basic
conclusion must share several key elements are,
• Stick with a basic synthesis of information
• Close with logic
• Speculate
• Pose a question
• Make a suggestion
• Leave out new information
58

How to do PhD?
(Phase – III)

HOW TO DO DOCTORAL RESEARCH?
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Outline
Introduction
Domain area Choosing
Phases in Research
Discussion

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It is all about you..
• You may be a PG student..
• You may be a faculty..
• If you are a PG student plan your career..
• Think about the project work right from
the start..
• If you are a faculty….

63
Phase 1
• You are planning to pursue Doctoral
Research.
• you are wavering…
• Am I competent?
• Will I be able to make it?
• Should I do or not?
• What happens if I …?

64
Ph.D start up preliminaries…(1/4 )
• When you have come to this stage it is
clearly understood that you have
completed M.Phil or M.E. Or any other
required entry qualifications.
• If you had an average or above average
academic background it is sufficient
enough.
• Even if you had a poor academic history
still you can make it provided…

65
• The first thing you have to understand is that it is
you who has got to do it.
• For this the drive has to come from within you.
• As your project evolves, you will get technical
and moral support from your supervisor and a
host of other people.
• However, success in your doctoral research
depends solely on your sustained and dogged
effort put forth by you.

66
• You should be self motivated and
committed and should be willing to work
hard over a long period.
• Remember doctoral research mostly is a
lonely business.
• Thus a larger effort is required in
conditioning your mind and steeling
yourself as compared to effort required in
the academic side.

67
Ph.D start up preliminaries…(4/4)
• On the technical side you require adequate
expertise in the chosen area.
• Familiarity with the tools that you are going to use.
• Incase you already do not posses these you have to
quickly master these through your course work or
otherwise
• I hope you had taken a deep breath and has
decided to take a plunge.
• Congratulations!
• You have taken the first important step.
• Phase1 is completed.

68
Ph.D requirements (1/3 )
• All universities prescribe some course work
• A pass* in the stipulated courses is mandatory.
• With most universities course work does not
carry any weight.
• Degree is awarded solely on the basis of the
appraisal by the examiners the thesis submitted
by you and the defense put up by you in the
public viva voce examination.

69
• Then what should be the standard of the thesis ?
• Be rest assured that you are not competing for
the Nobel Prize. How ever the following points
give an indication of the enormity of the problem.
• Ph.D. thesis is treated very seriously at all
leading universities.
• Expectations are high; Ph.D. thesis represents a
substantial work.

70
• Ph.D. thesis process transforms the student into
a professional researcher.
• Faculty are judged by the theses of their Ph.D.
students.
• A doctoral thesis must show evidence of
independent enquiry, originality in the methods
used and/or in the conclusions drawn and must
make an appreciable new contribution to
knowledge in the candidates field. A thesis must
be a candidate’s own.

71
Phase 2 : Choosing a topic…(1/9)
• The next step is to choose a suitable topic.
• There are two possible scenarios:
• You are joining a supervisor who is already
doing a very big project; already several
scholars are working with him; you are very, very
lucky in this case. you are handed down a well
defined problem; there are so many peers
working with you, to familiarize and explain the
nuances of the problem

72
• You get a head start, but …..
• In the second case you are on your own.
• You are expected to select a suitable
problem; suggest a suitable solution
methodology and convince the prospective
supervisor about your idea.
• Most of the research work that are done in
various universities fall under this
category.

73
• Firstly general guide lines:
• You must be enthusiastic about the topic.
• It must be do-able in 3 years.
• Solving the problem is worthy of a Ph.D.
• A major portion of the solution
methodology falls within your expertise
area.
• There is some supervisor in the
department willing to supervise.

74
• Then how to go about choosing a problem
to be solved by you?
• Firstly choose a broad area. May be the
subject you have secured high marks..but
not necessarily so. Any subject in which
you are instinctively confident enough will
be good.
• Choose a proper subset of the area.
• Example

An Example!
• Two important related research directions
should receive attention from the
researcher in sensor networks !
• These are design of routing protocols for
WSNs, and Three-dimensional (3D)
sensor fields !
75

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• Choose a particular aspect of the sub area
where a large number of recent good
publications are available.
• Browse internet download 40-50 papers.
• Go through them and select most
important 15 papers.
• Read through each one of them carefully.
• This is one of the most pains taking
stages.

77
• From among the 30-40 papers select the
most important 15 papers.
• Read each of this paper thoroughly. You
may not be able to understand at the first
instance. You may have to read several
other basic papers in order to understand
the current one.

78
• For each of the selected paper note down
the following:
• What is the contribution of the author?
• Are there any limitations?
• Can the limitations be overcome?
• Is there any scope for improving?
• Can I repeat the experiments locally?

79
Choosing a topic…(8/9)
• Once you have made your notes for all
the 15 papers get the collection of all the
scopes for future work.
• Critically evaluate them on the basis of:
• Importance; Your Expertise; Time and
resources available;
• Choose the most promising one.
• Make a write up; slides better

80
• Make a presentation to the prospective guide.
• He/She may accept your proposal (very rare),
suggest suitable modifications and ask you to
come out with a revised proposal or suggest
altogether a new area.
• Follow up and repeat the process until your
research topic is finalized between you and the
supervisor.

81
Phase 2 completed
• This completes Phase 2.
• You make an application and you are duly
registered with an university for doctoral
work.
• A doctoral committee is formed with your
supervisor as the convener.
• You are prescribed certain courses;
discuss with your supervisor and ensure
that really useful courses are prescribed.

82
Phase 3: Completion of the courses..
• Phase 3 is spread over an year.
• Targets:
• Completion of the Courses
• Familiarity with the tools
• Repetition of other’s experimental works
• Trying out ideas
• After completion of courses some universities
prescribe a comprehensive examination

83
Phase 4: Work Vigorously ..Publish(1/13)
• After successful completion of
examination only many universities
register you formally as a doctoral scholar.
• Phase 4 is the crucial period when actual
research is carried out.
• Work vigorously experiment, test, modify,
test …you find some thing worthwhile.

84
• This is the heart of your program..
• A few points may be noted.
• An element of race is involved in rearch.
• You may be doing lots of experiments
during this period.
• Ensure all experiments are properly
documented.. Date, time, place,
parameters set up ….
• Your experiments must be repeatable

85
• Remember some of your experiments may
be challenged and proper documentation
is absolutely necessary.
• Repeat the experiments several times in
several ways, where the results are novel
and rather unexpected.
• Since a large volume of data and results
will be collected use Quality Circle
methods..

86
• The 5 Ss
• 1.Seiri: Discard unnecessary items from the work place
• 2.Seiton: Arrange necessary items in good order.
• 3.Seiso: Let your work place be clean.
• 4.Seiketsu: Maintain high standards of house keeping
• 5.Shitsuke: Train your assistants to follow suit.

87
• You can use standard tools to in Statistics to
substantiate your theory /experimental results.
• Some of the tools are…
• Fuzzy logic
• Simulation methods
• Student’s ‘t’ test
• Five point summary
• Standard optimization techniques

88
Phase 4…Publish (6/13 )
• The need for publishing your findings
• University requirements
• Safe guarding your work
• Getting valuable inputs
• Publish/present in seminars and
conferences

89
Phase 4:..Publish (7/13 )
• How to write a Great paper..Simon Peyton
Jones Microsoft corpoation
• Writing paper-
• Forces us to be clear, focused
• Crystallizes what we don’t understand
• Opens the way to dialogue with others
• reality check, critique, and corroboration

90
• Write a paper, and give a talk, about any idea,
no matter how weedy and insignificant it may
seem to you Writing the paper is how you
develop the idea in the first place. It usually
turns out to be more interesting and challenging
that it seemed at first.
• The purpose of your paper is... to convey your
idea...from your head to your reader’s head
Everything serves this single goal.

91
• Writing the paper is how you develop
the idea in the first place.
• It usually turns out to be more interesting
and challenging that it seemed at first.
• Make the reader interested in your paper.
• A well written draft can make even an
ordinary work appealing.

92
Publish (10/13 ).. Your narrative flow
• It’s an interesting problem
• It’s an unsolved problem
• Here is a problem
• Here is my idea
• My idea works (details, data)
• Here’s how my idea compares to other
people’s approaches

93
Publish(11/13 ): Structure of the paper
• Title (1 or 2 lines)
• Abstract (4 sentences)
• Introduction (1 page)
• The problem (1 page)
• My idea (2 pages)
• The details (5 pages)
• Related work (1-2 pages)
• Conclusions and further work (0.5 pages)

94
Publish:(12/13 )..Abstract
• Used by program committee members to
decide which papers to read
• Four sentences [Kent Beck]
1.State the problem
2.Say why it’s an interesting problem
3.Say what your solution achieves
4.Say what follows from your solution
• Better if it is written at the last.

95
Publish:(13/13)..
• Try, try until you have a couple of good
publications under your belt.
• If you have achieved the target ,you can
breath easy and think about commencing
to write your thesis!

96
Phase 5: Start writing (1/3)
• If you have secured adequate number of
publications it is time to start writing up
your report.
• It takes 3 - 6 months to write the report.
• Report will be about 150 pages.
• The first step is to have a complete
reference list as per norms.
• It would be better if each reference is at
least referred once.

97
Phase 5 Start writing (2/3)
• Next step is to prepare a list of symbols.
• The report may have 5 – 7 chapters.
• The first chapter is Introduction. The last
segment of this chapter contains a brief
description of following chapters. In the
penultimate section of Introduction you
make your claims.
• The second chapter deals with the
literature survey.

98
Phase 5: Start writing (3/3)
• Your survey is expected to be comprehensive.
• The last chapter gives a list of conclusions and
also details scope for future work.
• Middle chapters deal with each of your
contributions.
• Once the draft is approved by your supervisor,
get the same audited for English.
• On an auspicious day you had submitted your
report to the university. …Good luck

99
Phase 6: Waiting period
• The next phase is anxious and frustrating
waiting period.
• It may be mere couple of months or may
spill over to year(s).
• Whatever it may be do not waste your
time.
• Keep the research fire burning, by
completing the papers, trying out
modifications.

100
Phase 6 Waiting period..
• This helps not only to keep your
frustrations under check, but also
enhances your preparedness for the viva
voce.
• Then one day you are informed by your
supervisor that your reports have been
received….

101
Phase 7 Viva voce
• Viva voce is the last hurdle.
• Prepare slides.
• Rehearse several times.
• Read and reread your report many, many
times.
• Keep copies of your experimental results
and readings.

102
Phase 7 Viva voce
• Speak confidently.
• Remember it is a public viva.
• Be polite but be firm in your articulations.
• At the end the examiners slowly rise from
their seats and inform the audience that
you are through.
• Congratulations! You have done it.

103
Must Read..
• How to write a great research paper and
get it accepted by a good journal –
Newman (slides)
• How to write a great research paper –
Peyton Jones (slides)
• Websites of foreign Universities

References
• A Survey on Routing Protocols for
Wireless Sensor Networks: Kemal Akkaya
and Mohamed Younis
• Routing Protocols in Wireless Sensor
Networks –A Survey: Shio Kumar Singh,
M P Singh,, and D K Singh
104

Research Issues on WSN

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