Cross-Layer Caching Based Optimization for Wireless

Multimedia Sensor Networks

Nestor Tiglao and António GriloINESC-ID/IST, Lisbon, Portugal

Outline

Introduction

Related Work

Proposed Mechanisms

Results

Conclusion and future work

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Introduction

WSN equipped with multimedia sensors givebirth to WMSN

They enable a new class of monitoring applications, but demanding in terms of: computational resources energy resources

Need for innovative solutions: combination/optimization techniques atthe different layers of the protocol stack

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Related Work

Pump Slowly Fetch Quickly (PSFQ) Designed for dynamic code update, no real-time performance guarantees

Distributed TCP Caching (DTC) Intermediate retransmission based on ACK/SACK semantic

Reliable Multi-Segment Transport (RMST) Uses timer-based NACK repair

Tunable Reliability with Congestion Control for Information Transport (TRCCIT) Uses MAC retry limit adaptation but considers end-to-end application reliability

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Analytical Model

N. M. C. Tiglao and A. M. Grilo, “An analytical model for transport layer caching in wireless sensor networks,” Performance Evaluation, vol. 69, no. 5, pp. 227–245, 2012. [Online]. Available: http://www.sciencedirect.com/science/article/pii/S0166531611001568

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Basic DTSN

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DSTN with NACK Repair

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Adaptive MAC Retry Limit Mechanism

Frame error rate

MAC retry limit

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Simulation Scenarios

Scenario 1: Local hotspot

Scenario 2: Global hotspot

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Goodput

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Scenario 1 Scenario 2

Goodput Performance Gain

Scenario 1

Scenario 2

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Packet Delivery – Scenario 1

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DTSN-CS0 DTSN-CS20

DTSN-CAM DTSN-CRAM

Packet Delivery – Scenario 2

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DTSN-CS0 DTSN-CS20

DTSN-CAM DTSN-CRAM

Energy Efficiency

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Scenario 1 Scenario 2

Energy Efficiency Gain

Scenario 1

Scenario 2

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Deadline Miss Ratio

Deadline: 500 ms

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Scenario 1 Scenario 2

End-to-end Delay

Scenario 1

Scenario 2

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Conclusion and Future Work

Ensemble of MAC and transport layer optimization provides better performance over non-optimized protocols

Mechanisms are simple and generic enough for adoption by other transport protocols

Future work: more complex and dynamic scenarios

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Thank you for your attention!

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