Distance Estimation by Constructing The Virtual Ruler in Anisotropic Sensor Networks

Yun Wang ,Kai Li, Jie Wu

Southeast University, Nanjing, China,

Temple University, Philadelphia, PA

INFOCOM 2010

Outline

Introduction Method Simulation Conclusion

Introduction

Locations of sensor nodes are important for operations in WSNs.

Introduction

Performance heavily depends on the precision of distance estimation.

Beacon node

Sensor node

Introduction

In an anisotropic WSN, huge errors may be introduced into distance estimation because of irregular deployment.

Beacon node

Sensor node

Objective

Make the estimated distance ED(s,t) as close to its corresponding D(s,t) as possible.

ED(s,t)

D(s,t)

System model & Assumptions

Large number of sensor nodes in a WSN so that any node is able to obtain enough neighboring nodes with a limited flooding operation.

Overview

Constructing The Virtual Ruler

Beacon node

Sensor nodeHole

TN:Turning Node

),(

),(),(=

ts

ts-tsMLink_error

ＤＤ

2.0=10

1012 -

1012

Overview

Constructing The Virtual Ruler

Beacon node

Sensor nodeHole

TN:Turning Node1012

Calculation of Dominating Degree

Observation

Calculation of Dominating Degree

Obtain a set of surrounding nodes by executing a limited flooding operation from m.

m

Hole

DD(n)=8

Avg_ DD(m)=7

DD(m)=6

Avg_ DD(m,n)-DD(m)=7-6=1

Threshold=2>1

Calculation of Dominating Degree

Obtain a set of surrounding nodes by executing a limited flooding operation from m.

n1

n2m

n

3

5

7

Hole

Calculation of Dominating Degree

n1

n2m DD(m)=6

Avg_ DD(m)=9

Avg_ DD(m,n)-DD(m)=3

Threshold=2<3

Distance Estimation

s

t

n1

)(

)(_*_=

mDD

mDDAvgScaleBasicfactor

Predefined parameter indicating the increasein Scale after a turning node

3

5

(3+5)*factor=8*0.85=6.8

6.8

hole

hole

21

23

22

211-

2

+=

dd

dddcosAngle

－

Distance Estimation

s t

n1

n2

n3

Review

The Virtual Ruler

Beacon node

Sensor nodeHole

TN:Turning Node

Simulation

Implemented the above algorithms in C++ 5548 nodes are randomly deployed Average node degree 6.2

Simulation

DV-DistanceOur method

Simulation

Simulation

Conclusion

Design and evaluate a new distance estimation scheme for anisotropic WSNs.

Thanks for your attention!!