臺灣博碩士論文加值系統

我們在無線感測網路中，提出一種新的具調適性的省電媒體存取控制協定，稱為EX-MAC。在現存的一些以省電為目的的媒體存取控制協定，如S-MAC，會讓感測節點周期性的進入睡眠模式以節省能源。然而在這些協定中，每個節點的工作周期(Duty cycle)在加入網路之前便決定了，在運作的時候也是維持固定不變。因此，當處於高流量的情況時，網路的效能會降低；在低流量時，不必要的能源消耗會加劇。在我們提出的EX-MAC協定中，每個感測節點會動態的調整自己的工作周期，使得節點的工作周期能符合網路的真實需求。EX-MAC調整工作周期的技術，是基於極值理論(Extreme value theory)來動態且準確的估計最適合的工作周期。因此，EX-MAC能夠適應網路流量、網路規模以及拓墣的變化。最後，我們的模擬結果顯示，相較於S-MAC，EX-MAC不僅消耗更少的能源，還具有更好的效能表現。

Acknowledgements ii
Abstract iv
Table of Contents v
List of Figures vi
Chapter 1 Introduction 1
Chapter 2 Related Work 4
Chapter 3 Problem Formulation 8
Chapter 4 Extreme Value Quantile Estimation 12
4.1. Extreme Value Theory 12
4.2. Estimation of the Extreme Value Index and Scale Factor 15
Chapter 5 Proposed MAC Protocol Design 18
5.1. Periodic Listen and Sleep 18
5.2. Dynamic Duty Cycle Adjustment 19
Chapter 6 Performance Evaluation 24
6.1. Comparison under Variable Packet Inter-arrival Time 25
6.2. Comparison under Variable Node Numbers 29
Chapter 7 Conclusions 33
Bibliography 34

[1] A. Salhieh, J. Weinmann, M. Kochhal and L.Schwiebert, “Power Efficient Topologies for Wireless Sensor Networks,” in ICPP’01, Valencia, Spain, pp.156-163, Sept. 2001.
[2] C. Intanagonwiwat, R. Govindan, and D. Estrin, “Directed Diffusion: A Scalable and Robust Communication Paradigm for Sensor Networks,” in proceedings of ACM/IEEE International Conference on MobiCom, Boston, MA, pp 56-67, 2000.
[3] Z. Chen and A. Khokhar, “Self Organization and Energy Efficient TDMA MAC Protocol by Wake up for Wireless Sensor Networks,” in IEEE SECON, pp. 335- 341, 2005.
[4] Junchao Ma and Wei Lou, “Energy Efficient TDMA Sleep Scheduling in Wireless Sensor Networks,” in Proc. of IEEE INFOCOM, Rio de Janeiro, pp.630-638, Apr. 2009.
[5] V. Rajendran, K. Obraczka, and J. J. Garcia-Luna-Aceves, “Energy-Efficient, Collision-Free Medium Access Control for Wireless Sensor Networks,” Proc. ACM SenSys ’03, pp. 181-92, Nov. 2003.
[6] Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specification, IEEE Std. 802.11-1999 edition.
[7] M. Stemm and R.H. Katz, “Measuring and reducing energy consumption of network interfaces in hand-held devices,” IEICE Trans. Commun., vol. E80-B, no. 8, pp.1125-1131, Aug. 1997.
[8] W. Ye, J. Heidemann, and D. Estrin, “Medium Access Control With Coordinated Adaptive Sleeping for Wireless Sensor Networks.” IEEE/ACM Transaction on Networking, vol. 12, no. 3, pp. 493-506, June. 2004.
[9] T. V. Dam and K. Lamgemdoen, “An Adaptive Energy-Efficient MAC Protocol for Wireless Sensor Networks,” in ACM SenSys 2003, pp. 171-180, 2003.
[10] C. Q. P. Lin and X. Wang, “Medium Access Control With A Dynamic Duty Cycle For Sensor Networks,” in IEEE WCNE, vol. 3, pp. 1534-1539, 2004.
[11] M.J. Schervish, Theory of Statistics. Springer, 1996.
[12] L. de Haan and A. Ferreira, Extreme Value Theory, An Introduction. Springer, 2006.
[13] A. L. M. Dekkers and J. H. J. Einmahl and L. De Haan, “A Moment Estimator for the Index of an Extreme-Value Distribution,” Ann. Statist., vol. 17, no. 4, pp. 1833-1855, 1989.
[14] B. M. Hill, “A Simple General Approach to Inference About the Tail of a Distribution,” Ann. Statist., vol. 3, no.5, pp. 1163-1174, 1975.
[15] I. S. Institute. Network Simulator NS-2. [Online]. Available: http://www.isi.edu/nsnam/ns/