uSense: A Unified Asymmetric Sensing Architecture for Wireless Sensor Networks

Yu Gu, Joengmin Hwang, Tian He and David Du

Minnesota Embedded Sensor System (MESS)Department of Computer Science & Engineering

http://mess.cs.umn.edu

Outline

Motivation Overview of uSense Architecture Global Scheduling Algorithms System Implementation and

Evaluation Conclusion

Motivation (Different Services)

Coverage

Life Time

Detection Delay

Stealth Distance

A Flexsible Solution?

…

C. Gui et al., Mobicom’04S. Ren et al., MC2R 2005

X. Wang et al. Sensys’03Q. Cao et al. IPSN’05C. Chiasserini et al. Infocom’04

T. Yan et al., Sensys‘03M. Cardei et al., Infocom’05

S. Kumar et al. Mobicom’04S. Slijepcevic et al. , ICC’01D. Tian et al. , Wireless Communications and Mobile Computing Journal 2003

New Design Philosophy

Sensor Functions

Essential functions Non-Essential functions

uSense Asymmetric Architecture

uSense Asymmetric Architecture

Sensor i

Sensor j

Sensor k

GenericSwitching Algorithm

Sensor Network

Algorithm 1

Algorithm 2

Algorithm n

…..

Para

met

er T

rans

latin

g

ComputationalEntity

Connectivity

Parameters

Generic Switching Algorithm

Scheduling Bits

Sensor i

Sensor j

Sensor k

GenericSwitching Algorithm

Sensor Network

Switching Rate

10110101

On

0.5HZ 16s round time

Algorithm2

Algorithm1

Algorithm2

Algorithm1

Algorithm2

Algorithm2

Algorithm1

Have We Solved Some Problems?

Flexibility issue of existing protocols?

Before:

Algorithm1

Complete code for

Algorithm2

Parameters2

Parameters2

Parameters2

Parameters2

Generic Switching

Generic Switching

Generic Switching

Generic Switching

Have We Solved Some Problems?

Flexibility issue of existing protocols?

uSense:Parameters1

Parameters1

Parameters1

Parameters1Schedule BitsSwitching

Rate

•Only need to disseminate two parameters

•Generic Switching unaffected

Outline

Motivation Motivation uSense ArchitectureuSense Architecture Global Scheduling Algorithms System Implementation and

Evaluation Conclusion

Sensor Network

Sensor i

Sensor j

Sensor j

Generic Switching Algorithm

Para

mete

r Tra

nsl

ati

ng

CCP

…

uScan

Virtual Patrol

Computational Entity

DiffSurv

Algorithm n

Algorithm 1

Algorithm 2

Algorithm 3Connectivity

Parameters

uScan Overview

Sensor Network

Sensor i

Sensor j

Sensor j

Generic Switching Algorithm

Para

mete

r Tra

nsl

ati

ng

CCP

…

uScan

Virtual Patrol

Computational Entity

DiffSurv

Connectivity

Parameters

Tile Level Scheduling

Line Scanning

Systolic Scanning

Node Level Scheduling

Para

mete

r Tra

nsl

ati

ng

CCP

…

uScan

Virtual Patrol

Computational Entity

DiffSurv

uScan Overview

Tile Level SchedulingTessellations

Line ScanEnergy saving

Systolic ScanMinimal Worst-case Breach

(10000)*

(00100)*

(00001)*

Node Scheduling {N1,N5} {N2,N3} {N1,N4}N2

N1

N3

N5

N4

T1

T2

T3

T4

T5

Schedule(N1)=(00100 00000 00100)*

Schedule(N2)=(00000 00100 00000)*

Schedule(N3)=(00000 00100 00000)*

Schedule(N4)=(00000 00000 00100)*

Schedule(N5)=(00100 00000 00000)*

(00100)*

Polynomial solution for set-cover

Physical Coverage

Bipartite Graph

Set Cover

Outline

MotivationMotivation Overview of uSense ArchitectureOverview of uSense Architecture Global Scheduling AlgorithmsGlobal Scheduling Algorithms System Implementation and

Evaluation Conclusion

System Implementation

Life Time under Full Coverage

At Node Density of 4, uSense outperforms DiffSurv 1.6 times

DiffSurv: T. Yan et al. “Differentiated Surveillance service for sensor networks”, Sensys 2003

Life Time under Partial Coverage

At Node Density of 10, uSense outperforms Virtual Patrol 27 timesVirtual Patrol: C. Gui and P. Mohapatra, “Virtual Patrol: a new power conservation design for surveillance using sensor

networks”, IPSN 2005

Future Work

Incorporating more sensing protocols to further strengthen the flexibility of uSense

Consider communication issues in uScan scenarios

Resilience to node failures

Conclusion (1)

uSense, provides a unified sensing architecture Simple generic switching algorithm in

sensor nodes Allows changing sensing algorithms

with only two parameters

Conclusion (2)

uScan, a two-level global scheduling algorithm Seamlessly supported by the uSense Generic node scheduling for different

sensing coverage requirements Significantly more energy efficient

than the localized algorithms