1. WTE-MAC Wakeup Time Estimation MAC For Improving End-to-End Delay Performance In WSN Jae-Ho Lee, Kyeong Hur and Doo-Seop Eom MILCOM, 2011

2. Outline Introductions Related Works Goals WTE-MAC Evaluations Conclusions

3. Introductions

4. Duty Cycle A B Wake up Sleep Wake up Sleep Wake up

5. Introductions Duty Cycle – synchronous A B Wake up Sleep Wake up Sleep Wake up SYNC Sleep Wake up

6. Introductions Duty Cycle – asynchronous A B Wake up Sleep Wake up Sleep Wake up Idle listening

7. Related Works B-MAC A B Wake up Sleep Wake up Sleep Wake up Joseph Polastre, Jason Hill, and David Culler. Versatile Low Power Media Access for Wireless Sensor Networks. In Proceedings of the Second International Conference On Embedded Networked Sensor Systems (SenSys 2004), pp. 95–107, November. 2004. preamble ACK DATA

8. Related Works X-MAC A B Wake up Sleep Wake up Sleep Wake up Michael Buettner, Gary V. Yee, Eric Anderson, and Richard Han. XMAC: A Short Preamble MAC Protocol for Duty-Cycled Wireless Sensor Networks. In Proceedings of the 4th International Conference on Embedded Networked Sensor Systems (SenSys2006), pp. 307–320, 2006. P ACK DATA PPP

9. Goal Improve end-to-end delay in multi-hop topologies with low power consumption

10. WTE-MAC SND: Synchronization at the Neighbor's Duty cycle Virtual Tunnel Construction Expanding SND into the multi-hop Environment

11. WTE-MAC SND: Synchronization at the Neighbor's Duty cycle Virtual Tunnel Construction Expanding SND into the multi-hop Environment

12. WTE-MAC A B Sleep Wake up Sleep Wake up P ACK DATA PPP Sleep Wake up RC = 1234 RI Neighbor table BInfo......... RX receive Wake up time Duty cycle period (DD) Early wakeup P ACK E wakeup,n+1

13. WTE-MAC SND: Synchronization at the Neighbor's Duty cycle Virtual Tunnel Construction Expanding SND into the multi-hop Environment

14. WTE-MAC Event (infrequent/bursty) Forward data FT : Fixing topology F E D C B A Virtual Tunnel

15. WTE-MAC Event (infrequent/bursty) Forward data FT : Fixing topology F E D C B A Virtual Tunnel

16. WTE-MAC SND: Synchronization at the Neighbor's Duty cycle Virtual Tunnel Construction Expanding SND into the multi-hop Environment

17. WTE-MAC A B Wake up Sleep Wake up Sleep Wake up P A PP C Sleep PP RC = 123 45 A Sleep C B A Wake up P 1 A P 1 A Virtual Tunnel Sleep End-to-End Delay without SND End-to-End Delay after SND RI E wakeup,n+1

18. WTE-MAC A B Wake up Sleep Wake up Sleep Wake up P A PP C Sleep PP 123 45 A C B A Wake up Virtual Tunnel Sleep RI Sleep Wake up Sleep D ack

19. Evaluation ParameterValue Duty Cycle period1 second RF Tx Rate250kbps Traffic SourceVBR 100kbps Average Packet Length128Bytes Initial Wakeup Time Rate10% / Duty Cycle Routing AlgorithmAODV, Flooding Power in state(Sleep/Wakeup)0.4 / 8.7 (μA) Power in mode(Tx/Rx)28.9 / 15.2 (mA) Communication Range200 meter CCA Effective Range280 meter Interference Range680 meter Default Simulation time100,000 second

20. Evaluation

27. Conclusions The SND mechanism that is designed to reduce the delivery delay per link The Virtual Tunnel that is created by expanding the SND into the multi-hop can provide an enhanced performance of end-to-end delivery delay It is energy efficient by decreasing unnecessary retransmissions.