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This paper introduces uSense, a unified asymmetric sensing architecture for wireless sensor networks. It provides a simple, generic switching algorithm that allows for changing sensing algorithms with only two parameters. Additionally, it presents uScan, a two-level global scheduling algorithm that is seamlessly supported by uSense, providing significantly more energy efficiency than localized algorithms.
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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) … Life Time Coverage S. Kumar et al. Mobicom’04 S. Slijepcevic et al. , ICC’01 D. Tian et al. , Wireless Communications and Mobile Computing Journal 2003 T. Yan et al., Sensys‘03 M. Cardei et al., Infocom’05 Detection Delay Stealth Distance A Flexsible Solution? X. Wang et al. Sensys’03 Q. Cao et al. IPSN’05 C. Chiasserini et al. Infocom’04 C. Gui et al., Mobicom’04 S. Ren et al., MC2R 2005
New Design Philosophy Sensor Functions Essential functions Non-Essential functions uSense Asymmetric Architecture
Parameters Connectivity uSense Asymmetric Architecture
Generic Switching Algorithm • Scheduling Bits • Switching Rate 0.5HZ 16s round time 1 0 1 1 0 1 0 1 On
Have We Solved Some Problems? • Flexibility issue of existing protocols? Algorithm2 Algorithm1 Before: Algorithm2 Algorithm1 Algorithm2 Algorithm1 Complete code for Algorithm2 Algorithm2 Algorithm1
Have We Solved Some Problems? • Flexibility issue of existing protocols? Parameters2 Parameters1 uSense: Generic Switching Parameters1 Parameters2 Generic Switching • Only need to disseminate two parameters • Generic Switching unaffected Generic Switching Schedule Bits Switching Rate Parameters1 Parameters2 Generic Switching Parameters2 Parameters1
Outline • Motivation • uSense Architecture • Global Scheduling Algorithms • System Implementation and Evaluation • Conclusion
uScan Overview Sensor Network Computational Entity Parameters Parameter Translating Algorithm 1 DiffSurv Sensor i Sensor j Algorithm 2 CCP Sensor j Algorithm 3 Virtual Patrol Connectivity Generic Switching Algorithm … Algorithm n uScan
Tile Level Scheduling Line Scanning Systolic Scanning Node Level Scheduling uScan Overview Sensor Network Computational Entity Computational Entity Parameters Parameter Translating DiffSurv Parameter Translating DiffSurv Sensor i Sensor j CCP CCP Sensor j Virtual Patrol Virtual Patrol Connectivity Generic Switching Algorithm … … uScan uScan
Tile Level Scheduling • Tessellations • Line Scan • Energy saving • Systolic Scan • Minimal Worst-case Breach (10000)* (00100)* (00001)*
Node Scheduling (00100)* • {N1,N5} • {N2,N3} • {N1,N4} T1 T2 N2 N1 T3 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)* T4 N4 N3 T5 N5
Polynomial solution for set-cover Bipartite Graph Set Cover Physical Coverage
Outline • Motivation • Overview of uSense Architecture • Global Scheduling Algorithms • System Implementation and Evaluation • Conclusion
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 times Virtual 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