globecom2012 slides

7/29/2019 Globecom2012 Slides

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n eepwa eup c e u ngo

ofWirelessSensors

, ,SungSik Kwon1,andAlade O.Tokuta1

1NorthCarolina

Central

Universit

Durham

USA

2RenminUniversityofChina,Beijing,China


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AgendaIntroduction

Pre iminaries

TwoApproaches

CaseStudy

Conclusion


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WirelessSensor Network

Component

SensorDataProcessor

WirelessCommunicationModule

SmallSize

LowPower


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Sleepwakeup Scheduling

Sensornetworkis

ener

deficient

randomdeploymentistypical,andthus

re un ancy

s

n er n


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SensorNetwork

Coverage

Model

Applicationsofwirelesssensornetwork

Disasterrescue

environmental

monitorin

battlefieldsurveillance,intrusiondetection,etc.

Most

case,

need

to

cover

whole

area

of

interest,e.g.battlefieldsurveillance


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BarrierCoverage Model

Some applicationsneedto

providea

partial

coverage,

e.g.intrusiondetection

Barriercoverage

model

Warning

Sleepwakeupschedulingisstillapplicableandimportant

Users


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Summaryof

Contribution

Introduceasecurityproblem,thebarrier

breachproblem,

in

existing

sleep

wakeup

sc e u nga gor ms or emax mum e mebarriercoverageproblem

Provideasufficientconditiontopreventthispro em

Basedonthiscondition,tworemediesareproposedandcompared


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barrier

coverage

IntroducedbyKumaretal.[1]

Com utin

barriercovers

Anyintruderwillbedetectedatleastktimes

SensorNetworkN overabeltre ion


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Maximum LifetimeBarrier

coverageProblem

Stemsfrom barriercoverage

Once

k

node

disjoint

barriers

are

identified,

activate

StartusingtheonelocatedoutermostKumaretal.[2]proposedoptimalsleepwakeup

sc e u ing

a gorit ms,

Stint uni orm

remaining

energylevel)

and

Prahari (non

uniform)

=


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StintStint : (Optimal) SleepwakeupAlgorithmforBarriercoverage

ofWireless

Sensors

with

Same

Remaining

Energy

Level

Step1)ComputeacoveragegraphG fromagiven

setN of

nodes,

G =

(V (G),

E (G))

ep2 ompu e emax mumnum ermo no edisjointpathsbetweenthevirtualnodessandt inG

Step3)Fromtheoutputofthesecondstep,findmnodedisjointpaths


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Stint cont

ofnodes,G =(V (G),E (G))x

aa

c

d

c

t1g

sb

bs2g

ee


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Stint cont

disjointpathsbetweenthevirtualnodessandt inG

a

d

ina

indouta

outd

c inc intoutt

outc

in

b

in

eoutb

out

e out

Applyamaxflow algorithm!!Flowalgorithmdoesnot


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Stint cont

ep3 rom eou pu o esecon s ep,

find

mnode

disjoint

paths

1B

2

3B

5B

7B


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Problem Description

xx

xAssumeanintruderfromxtoy

a a

c1g

c1g

c1g

b2 2

b2

e e


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Problem Description cont

BothStintandPrahari suffersfromBarrierbreach

Barrierbreaches

may

exist

if

two

edges

in

two

differentbarrierscrosswitheachother

Amaxflowdoesnotconcernaboutthose

crossingedges

Thereexistsascheduleforasetofbarriercoverswhich

doesnot

allow

any

barrier

breach

between

any

pair

of

barriercoversifnotwobarriercoversinthesetare

crossingeachother


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FirstSolution

AremedyontheoutputofStint

Giving

up

some

of

the

barrier

covers

barriercoversCanbeconvertedtomaximumindependentset

pro ema

ba

c

e

b

e

c


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FirstSolution

cont

MaximumindependentsetproblemisNPhard

Bo ana andHalldrssons a roximation

algorithm[3]canbeapplied

ad

a d

b

c b

ec

e


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SecondSolution

Planargraph

Notwo

ed es

are

crossin

with

each

other

Corollary1.

TheStint

always

generates

an

optimallifetimenonpenetrablebarriercoverage

ofsensorsifaG inducedfromasetN ofsensors

by

Step

1)

of

Stint

is

a

planar

graph


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SecondSolution

cont

Idea

Eliminateedges

to

make

the

input

induced

graphplanar

AlgorithmIterativel identif andremoveaned ewhichiscrossingwiththemostnumberof

theother

edges

until

the

graph

becomes

planar

ApplyStint


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Approach 1is

better

Approach1produces2nodedisjointpaths

A roach2

roduces

nodedis oint

aths

2v

1v

3v

4v 10v

9

11v

12v

13

2vs

1v

3v

4v

v

10v

9

11v

12v

13v

2v

s

1

3v

4v 10v

9

11v

12v

13

6v

8v

7v 14v

15v

16v 6v

8v

7v 14

15v

16v 6v

8v

7v 14v

15v

16v

(a) (b) (c)


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Approach 2is

better

Approach1produces3nodedisjointpaths

A roach2

roduces2node

dis oint

aths

2v 2v 2v

1v

s3v

4v 1v

s3v

4v 1v

s3v

4v

6v

5v

7v

9

10v

11v12v

6v

9

10v

11v12v

6v

5v

7v

9

10v

v12v

(a) (b) (c)


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ConclusionIntroduceanewsecurityproblem

The

barrier

breach

problem

Provideasufficientconditiontopreventthisproblem

Based

on

this

condition,

two

remedies

are

proposed

andcompared

rs one sapp e o eou pu o n

SecondoneisappliedtotheinputofStint

epen ngon

e

npu

grap ,

one

o

e

a gor m

worksbetterthantheother.


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References[1]S.Kumar,T.H.Lai,andA.Arora,BarrierCoveragewithWirelessSensors,inProc.ofthe11thAnnualInternationalm),2005.

2 S.Kumar,T.H.La ,M.E.Posner,an P.S n a, Max m zng

the

Lifetime

of

a

Barrier

of

Wireless

Sensors,

IEEETran

sactionsonMobileCom utin TMC vol. no.8 Au ust2010.

.

. .

,

ximumIndependentSetsbyExcludingSubgraphs,BITNumericalMathematics,vol.32,no.2,pp.180196,1992.

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