A Better Choice for Sensor Sleeping

Ou Yang and Wendi Heinzelman

1-28-2009

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Outline

Motivation and Goal Methodology

- Sleep at single layer individually- Sleep at multiple layers simultaneously

Simulation Results- Performance of single layer sleeping- Comparisons of single layer sleeping- Comparisons of multi-layer sleeping

Conclusions

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Motivation

Wireless sensors are energy constrained

Save energy to extend network lifetime

Make sensors sleep when they are not used

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Motivation

How to make sensors sleep?

Application Layer

Routing Layer

MAC Layer

Source node selectione.g. target tracking [1]

Topology controle.g. GAF [2]

Routing protocole.g. [3]

Duty-cycled MAC protocole.g. SMAC [4]

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Goal

Which is better?- Given application requirements- Given network scenario

Is there a single layer providing most benefit?

Multi-layer better than individual layer? Need cross-layer coordination?

Application Layer

Routing Layer

MAC Layer

Source node selectione.g. target tracking [1]

Topology controle.g. GAF [2]

Routing protocole.g. [3]

Duty-cycled MAC protocole.g. SMAC [4]

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Methodology Focus on the routing and MAC protocol

Application Layer

Routing Layer

MAC Layer

Source node selectione.g. target tracking [1]

Topology controle.g. GAF [2]

Routing protocole.g. [3]

Duty-cycled MAC protocole.g. SMAC [4]

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Methodology All combinations of sleeping schemes

Non-sleeping Sleeping

Directed Diffusion [5]Sleeping Directed Diffusion

IEEE 802.11 [6] SMAC [4]

Routing Protocol

MAC Protocol

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Non-sleeping Routing Protocol -Directed Diffusion [5]

Data-centric- Data is named in attribute-value pairs

Exploratory phase - Discover source nodes- Low data rate flooding

Reinforcement phase- “Pull down” data from selected source node- High data rate unicast

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Directed Diffusion

Sink Source

INTEREST (periodic flooding)

exploratory DATA (periodic flooding)

positive REINFORCEMENT (unicast)

high rate DATA (unicast)

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Directed Diffusion

Interest

Data

Data

Interest (low rate)

Pos reinforcement (high rate)exploratory data (low rate)

Data (high rate)

Put them to sleep!

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Sleeping Routing Protocol - Sleeping Directed Diffusion

Node

INTEREST (periodic flooding)

exploratory DATA (periodic flooding)

positive REINFORCEMENT (unicast)

high rate DATA (unicast)

INTERESTtimer

gapDATA timer gap

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Sleeping MAC – SMAC [4]

Duty-cycled MAC- Fixed awake time in a cycle

Synchronization- Periodic SYNC packets

Similar to IEEE 802.11- CSMA- RTS/CTS

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Sleep at both layers

Sleeping

Sleeping Directed Diffusion

SMAC

Routing Protocol

MAC Protocol

Coordination? How to

coordinate?

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Sleep at both layers

Problem - When sleeping at routing layer, no need to wake up at MAC layer

Coordination- Routing protocol has higher priority to put sensor to sleep

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Sleep at both layers

Problem- MAC updates topology according to periodic SYNC packets- MAC cannot differentiate routing layer sleeping and energy depletion

Coordination- Add energy info into SYNC packets

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Performance: single layer sleeping

QoS pauseLower data deliver ratio

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Comparisons: single layer sleeping Change node density Higher density

Higher contention

Lower throughputLower delivery ratio

Higher densityHigher redundancy

Higher throughput

Lower delivery ratiodue to more QoS pauses

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Comparisons: single layer sleeping Change network scale Larger network

More hops to sink

Lower throughputLower delivery ratio

Larger networkSame redundancy

Similar throughputSimilar delivery ratio

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Comparisons: single layer sleeping Change number of source nodes

More source nodes, fewer hops to sink

Higher throughputHigher delivery ratio

More source nodes, more redundancy

Higher throughput

Lower delivery ratio due to more QoS pauses

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Comparisons: single layer sleeping Change application data rate

Higher data rate, higher contention

Lower throughput/rate Lower delivery ratio

Higher data rate, same redundancy

Similar throughput/rateSimilar delivery ratio

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Comparisons: multi-layer sleeping Change node density

No coordinationno gain

Need coordinationin lower contentionscenarios

Sacrifice delivery ratio

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Discussions

Other routing protocols?- Sensors sleep when not routing data- e.g., Geographic routing

Other MAC protocols?- Duty-cycled MAC- e.g., T-MAC, B-MAC

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Conclusion and Future Work

MAC layer sleeping is better when- Low contention- Small network scale

Routing layer sleeping is better when- Higher redundancy- Larger network scale

Multi-layer sleeping is better when- Proper coordination- Low contention

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References [1] Zoghi, M.R., Kahaei, M.H.: Sensor Selection forTarget Tracking in WSN Using

Modified INS Algorithm. In: 3rdInternatioanl Conference on Information and CommunicationTechnologies: From Theory to Applications, pp. 1-6. 2008

[2] Xu, Y, Heidemann, J., Estrin, D.: Geography-informed Energy Conservation for Ad HocRouting. In: 7th Annual International Conference on Mobile Computingand Networking, pp. 70-84. 2001

[3] Zheng, R., Kravets, R.: On-demand PowerManagement for Ad Hoc Networks. In: 22nd Annual Joint Conference ofthe IEEE Computer and Communications Societies, vol.1, pp. 481-491. 2003

[4] Ye, W., Heidemann, J., Estrin, D.: Medium Access Control with Coordinated Adaptive Sleeping for WirelessSensor Networks. IEEE/ACM Trans. on Networking, vol. 12,issue 3, pp. 493-506. 2004

[5] Intanagonwiwat, C. Govindan, R. Estrin, D. Heidemann,J.: Directed Diffusion for Wireless Sensor Networking. IEEE/ACM Trans. on Networking, vol. 11, issue 1, pp. 2-16. 2003

[6] LAN MAN Standards Committee of the IEEE Computer Society: Wireless LAN medium access control (MAC) and physical layer (PHY) specification, IEEE, New York, NY, USA, IEEE Std 802.11-1997 edition, 1997

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Thank you

Q & A