WiMob 2012 presentation

1. Cross-Layer Caching Based
Optimization for Wireless
Multimedia Sensor Networks
Nestor Tiglao and António Grilo
INESC-ID/IST, Lisbon, Portugal

2. Outline
 Introduction
 Related Work
 Proposed Mechanisms
 Results
 Conclusion and future work
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3. Introduction
 WSN equipped with multimedia sensors give
birth 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 at
the different layers of the protocol stack
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4. 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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5. 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/S0
166531611001568
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6. Basic DTSN
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7. DSTN with NACK Repair
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8. Adaptive MAC Retry Limit Mechanism
 Frame error rate  i , j  pi1,jr
  log  i , j  log pi , j  
 
 MAC retry limit ri  max 3,  
 
  log pi , j 

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9. Simulation Scenarios
 Scenario 1: Local hotspot
 Scenario 2: Global hotspot
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10. Goodput
Scenario 1 Scenario 2
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11. Goodput Performance Gain
 Scenario 1
 Scenario 2
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12. Packet Delivery – Scenario 1
DTSN-CS0 DTSN-CS20
DTSN-CAM DTSN-CRAM
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13. Packet Delivery – Scenario 2
DTSN-CS0 DTSN-CS20
DTSN-CAM DTSN-CRAM
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14. Energy Efficiency
Scenario 1 Scenario 2
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15. Energy Efficiency Gain
 Scenario 1
 Scenario 2
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16. Deadline Miss Ratio
Scenario 1 Scenario 2
 Deadline: 500 ms
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17. End-to-end Delay
 Scenario 1
 Scenario 2
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18. 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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19. Thank you for your attention!
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