在隨意型無線網路（Mobile Ad hoc Network，MANET）中，無線網路的壽命依賴於行動端點的電池能量，所以能量保存是一個很重要的課題，因此我們期望設計出一個可相容於現今的IEEE 802.11 協定，並且能有效節省耗電量的新協定。在IEEE 802.11 DCF 模式下的能量保存模式（Power Saving Mode）中，每個行動端點必須週期性地醒來，以判斷是否有傳送或接收的動作產生。然而這種方式需要週期性醒來，因此省電效率並不是很好。本篇論文提出一個嶄新並更加省電的協定，此方法可以增加電池能量的耐久性，進而延長行動端點與網路的壽命，同時也相容於現今的IEEE 802.11 協定。此協定是藉由Quorum 的特性，使每個行動端點不需要在每個週期醒來，但仍然可以經由彼此交集而達到互相通訊的效果，並且延長連續睡眠時間以達到省電的效果。模擬的結果指出這個新的能量保存協定的延遲時間會較長，但可以延長整個MANET 的網路壽命。

The lifetime of a mobile ad hoc network (MANET) depends on the durability of the battery resource of mobile hosts. In IEEE 802.11 Power Saving Mode, a mobile host must wake up in every beacon interval to check if it needs to remain awake for that particular beacon interval. Such a scheme fails to adjust a mobile host’s sleep duration according to its traffic thereby reducing its power efficiency. This paper presents the new MAC protocols for power saving in a MANET. The essence of these protocols is a quorum-based sleep/wake-up mechanism which conserves energy by allowing mobile hosts to sleep more than one beacon interval, if they involve a few transmissions. The proposed protocols are simple and compatible to the IEEE 802.11 standard. Simulation results show that our protocols conserve more energy and extend the lifetime of a MANET without increasing packet loss ratio.

Mechanism for Power Saving in random-access Ad-Hoc Wireless Local Area
Networks,” in Proceedings of Mobile Multimedia Communications 1999, (San
Diego, CA, USA), pp. 114–123, Nov. 1999.
[2] R. Bruno, M. Conti, and E. Gregori, “Optimization of E ciency and Energy
Consumption in p-Persistent CSMA-Based Wireless LANs,” IEEE Transactions
on Mobile Computing, vol. 1, pp. 10–31, Jan.-Mar. 2002.
[3] E.-S. Jung and N. H. Vaidya, “An Energy E cient MAC Protocol for Wireless
LANs,” in Proceedings of INFOCOM 2002, (New York, NY, USA), pp. 1756–
1764, Jun. 2002.
[4] Y.-C. Tseng, C.-S. Hsu, and T.-Y. Hsieh, “Power-Saving Protocols for IEEE
802.11-Based Multi-Hop Ad Hoc Networks,” in Proceedings of INFOCOM 2002,
(New York, NY, USA), pp. 200–209, Jun. 2002.
[5] S.-L. Wu, Y.-C. Tseng, and J.-P. Sheu, “Intellegent Medium Access for Mobile
Ad Hoc Networks with Busy Tones and Power Control,” IEEE Journal on
Selected Areas in Communications, vol. 18, pp. 1647–1657, Sep. 2000.
[6] J. C. Cano and P. Manzoni, “Reducing Energy Consumption in a Clustered
MANET using the Intra Cluster Data-Dissemination Protocol (Icdp),” in Pro-
ceedings of the 10th. Euromicro Workshop on Parallel, Distributed and Networkbased
Processing, (Canary Islands, Spain), pp. 411–418, Jan. 2002.
[7] B. Chen, K. Jamieson, H. Balakrishnan, and R. Morris, “Span: An Energy-
E cient Coordination Algorithm for Topology Maintenance in Ad Hoc Wireless
Networks,” in Proceedings of MOBICOM 2001, (Rome, Italy), pp. 85–96, Jul.
2001.
[8] Y. Xu, J. Heidemann, and D. Estrin, “Geography-informed Energy Conservation
for Ad Hoc Routing,” in Proceedings of MOBICOM 2001, (Rome, Italy),
pp. 70–84, Jul. 2001.
[9] S. Agrawal and S. Singh, “An Experimental Study of TCP’s Energy Consumption
over A Wireless Link,” in Proceedings of the 4th. European Personal Mobile
Communications Conference, (Vienna, Austria), Feb. 2001.
[10] M. Zorzi and R. R. Rao, “Is TCP Energy E cient?,” in Proceedings of Mobile
Multimedia Communications 1999, (San Diego, CA, USA), pp. 198–201, Nov.
1999.
[11] A. Kamerman and L. Monteban, “WaveLanII: A High-Performance Wireless
LAN for The Unilicensed Band,” Bell Labs Technical Journal, vol. 2, Summer
1997.
[12] IEEE 802.11 Standard (IEEE Computer Society LAN MAN Standards Committee),
Wireless LAN Medium Access Control and Physical Layer Specifications,
Aug. 1999.
[13] W. Stallings, SNMP, SNMPv2, SNMPv3, and RMON 1 and 2. Third Edition,
pp. 33–34. Addison-Wesley, 1999.
[14] H. Garcia-Monina and D. Barbara, “How to Assign Votes in a Distributed
Systems,” Journal of the ACM, vol. 32, pp. 841–860, Oct. 1985.
[15] G. Ricart and A. K. Agrawala, “An Optimal Algorithm for Mutual Exclusion
in Computer Networks,” Communications of the ACM, vol. 24, pp. 9–17, Jan.
1981.
[16] M. Singhal and N. G. Shivaratri, Advanced Concepts in Operating Systems,
p. 345. McGraw-Hill, 1994.
[17] R. H. Thomas, “A Majority Consensus Approach to Concurrency Control,”
ACM Transaction on Database Systems, vol. 4, pp. 180–290, Jun. 1979.
[18] D. Agrawal and A. E. Abbadi, “An E cient and Fault-Tolerant Solution for Distributed
Mutual Exclusion,” ACM Transaction on Computer Systems, vol. 9,
pp. 1–20, Feb. 1991.
[19] S.-Y. Cheung, M. H. Ammar, and M. Ahamad, “The Grid Protocol: A High
Performance Scheme for Maintaining Replicated Data,” IEEE Transaction on
Knowledge and Data Engineering, vol. 4, pp. 582–592, Dec. 1992.
[20] M. Maekawa, “A pN Algorithm for Mutual Exclusion in Decentralized Systems,”
ACM Transaction on Computer Systems, vol. 3, pp. 145–159, May 1985.
[21] H. Chen and J. Tang, “An E cient Method for Mutual Exclusion in Truly
Distributed Systems,” in Proceedings of the 14th. International Conference on
Distributed Computing Systems, (Pozman, Poland), pp. 97–104, Jun. 1994.
[22] A. Kumar, “Hierarchical Quorum Consensus: A New Algorithm for Managing
Replicated Data,” IEEE Transaction on Computers, vol. 40, pp. 996–1004, Sep.
1991.
[23] Y.-C. Kuo and S.-T. Huang, “A Geometric Approach for Constructing Coteries
and k-Coteries,” IEEE Transaction on Parallel and Distributed Systems, vol. 8,
pp. 402–411, Apr. 1997.
[24] S. Lang and L. Mao, “A Comparison of Two Torus-Based K-Coteries,” in Proceedings
of the International Conference on Parallel and Distributed Systems,
(Tainan, Taiwan), pp. 300–306, Dec. 1998.
[25] W.-S. Luk and T.-T. Wong, “Two New Quorum Based Algorithms for Distributed
Mutual Exclusion,” in Proceedings of the 17th. International Conference
on Distributed Computing Systems, (Baltimore, MD, USA), pp. 95–99,
May 1997.
[26] Y.-T. Wu, Y.-J. Chang, S.-M. Yuan, and H.-K. Chang, “A New Quorum-Based
Replica Control Protocol,” in Proceedings of Pacific Rim International Symposium
on Fault-Torelant Systems, (Taipei, Taiwan), pp. 116–121, Dec. 1997.
[27] The Network Simulator - ns-2. http://www.isi.edu/nsnam/ns/.
[28] The CMU Monarch Project’s Wireless and Mobility Extensions to ns.
http://www.monarch.cs.cmu.edu/, Aug. 1998.