以集中式協調為基礎的合作網路中選取合作夥伴之機制

簡易檢索 / 詳目顯示

回結果列表

研究生：	陳瀅心 Ying-Shin Chen
論文名稱：	以集中式協調為基礎的合作網路中選取合作夥伴之機制 A Partner Choosing Algorithm in Polling-based Cooperative Networks
指導教授：	陳志成 Jyh-Cheng Chen
口試委員:
學位類別：	碩士 Master
系所名稱：	電機資訊學院 - 資訊工程學系 Computer Science
論文出版年：	2007
畢業學年度：	95
語文別：	英文
論文頁數：	41
中文關鍵詞：	合作網路、選取合作夥伴、空間多元性、集中式協調系統
外文關鍵詞：	Cooperative Networks, partner choosing, spatial diversity, IEEE 802.11 PCF
相關次數：	點閱：2 下載：0
分享至:	分享至facebook 分享至twitter

查詢本校圖書館目錄查詢臺灣博碩士論文知識加值系統勘誤回報

近年來，隨著無線網路的廣泛使用，各種應用程式日新月異，對無線網路的需求更是與日遽增。但相對於有線網路，由於無線訊號的不穩定性，在無線網路中提供穩定的服務是很重要的議題。以最被廣泛使用的無線區域網路技術IEEE802.11為基礎，此篇論文針對無線訊號的不穩定性提出可增進效能的方法。

目前已有一些不同形式的多元性的使用來對抗無線網路訊號無法預測的波動。其中，空間上的多元性是最多人使用的。此論文主要利用空間多元性的優點提出新的增進802.11集中式網路效能的方法。網路協調者利用位置資訊來分配幫手給各使用者，如此一來即使遭遇訊號不良的情形也可以經由幫手完成資料的傳遞，所提出的方法不僅提高資料的傳送量，並可平均分配幫忙其他使用者的工作量到所有使用者。模擬的結果亦支持所提出的方法可以達到更高的效能。

Quality of service (QoS) in multimedia applications has become an important issue. Due to the lack of radio link stability, QoS in wireless networks is more challenging than that in wired networks. This thesis provides an enhancement for the most widely deployed wireless
LAN technology, IEEE 802.11. Because of the suffering from severe variation in channel condition, some forms of diversity have been proposed to combat the effects of fading. Spatial diversity is one of the well-known forms of diversity. In this thesis, a solution to improve the performance of the polling-based Point Coordination Function (PCF) in 802.11 via user spatial cooperation diversity is proposed. Wireless stations are assigned partners so that they can overcome the fluctuant channel conditions. The proposed method not only increases users’ throughput, but also balance the load of help among all wireless stations. The use of spatial diversity has critical influence on the performance of PCF. The simulation
results show that the proposed method outperforms the original polling-based system no matter in throughput, delay, or packet loss ratio. The solutions proposed in this thesis are fully complied with IEEE 802.11. By extensive simulation, it has been shown that the proposed solutions are both efficient and practical.

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1. Cooperative Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. IEEE 802.11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1. Distributed Coordination Function (DCF) . . . . . . . . . . . . . . 3
2.2. Point Coordination Function (PCF) . . . . . . . . . . . . . . . . . 5
3. Background and literature work . . . . . . . . . . . . . . . . . . . . . . . 5
Proposed Partner Choosing Algorithms . . . . . . . . . . . . . . . . . . . . . 8
1. Static partner choosing algorithm in PCF . . . . . . . . . . . . . . . . . . . 10
2. Dynamic partner choosing algorithm in PCF . . . . . . . . . . . . . . . . . 16
Simulation and Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . 26
1. Simulation Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
List of Tables
1. Simulation parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
List of Figures
1. Structure in IEEE 802.11 MAC . . . . . . . . . . . . . . . . . . . . . . . . 3
2. IEEE 802.11 DCF Operation . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. IEEE 802.11 PCF Process . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1. The Process of Whisper . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2. The Process of Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3. The Format of 802.11 Association Request Message . . . . . . . . . . . . 11
4. How to Choose Helper . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5. The Form of The Helper Structure . . . . . . . . . . . . . . . . . . . . . . 12
6. An Example Scenario . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7. The Helper Structure of Station 1 . . . . . . . . . . . . . . . . . . . . . . . 16
8. The Helper Structure of Station 3 . . . . . . . . . . . . . . . . . . . . . . . 17
9. The Helper Structure of Station 6 . . . . . . . . . . . . . . . . . . . . . . . 18
10. The Best Condition After Choosing (Helper, Under) Pair . . . . . . . . . . 19
11. Station 1 Has a Bad Channel and Choose a Helper . . . . . . . . . . . . . . 21
12. Station 6 Has a Bad Channel and Choose a Helper . . . . . . . . . . . . . . 22
13. The Channel Between Station 6 and 5 Becomes Poor . . . . . . . . . . . . 23
14. Station 2 Turns to Bad State . . . . . . . . . . . . . . . . . . . . . . . . . 24
15. Station 3 and 6 Have to Change Their ( Helper, Under ) Pair . . . . . . . . 25
1. The Simulation Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2. The Error Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3. The Topology of The First Part Simulations . . . . . . . . . . . . . . . . . 29
4. The Throughput Results of PCF, Static Cooperative PCF, and Dynamic Cooperative
PCF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5. The Delay Results of PCF, Static Cooperative PCF, and Dynamic Cooperative
PCF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6. The Packet Loss Ratio Results of PCF, Static Cooperative PCF, and Dynamic
Cooperative PCF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7. The Throughput Results of PCF, Static Cooperative PCF, and Dynamic Cooperative
PCF With Packet Error Rate 0.3 . . . . . . . . . . . . . . . . . . 33
8. The Delay Results of PCF, Static Cooperative PCF, and Dynamic Cooperative
PCF With Packet Error Rate 0.3 . . . . . . . . . . . . . . . . . . . . . 33
9. The Packet Loss Ratio Results of PCF, Static Cooperative PCF, and Dynamic
Cooperative PCF With Packet Error Rate 0.3 . . . . . . . . . . . . . . . . . 34
10. The Distribution of The Load of Help Among All The Stations . . . . . . . 36

                                

Bibliography
[1] J. Laneman, D. Tse, and G. Wornell, “Cooperative diversity in wireless networks: Efficient
protocols and outage behavior,” vol. 50, pp. 3062–3080, Dec. 2004.
[2] J. G. Proakis, “Digital Communications, 4th ed,” 2001.
[3] A. Sendonaris, E. Erkip, and B. Aazhang, “User Cooperation Diversity–Part I: System
Description” and “User Cooperation Diversity–Part II: Implementation Aspects and
Performance Analysis,” Nov. 2003.
[4] A. Sendonaris, E. Erkip, and B. Aazhang, “Increasing uplink capacity via user cooperation
diversity,” in Information Theory, 1998. Proceedings. 1998 IEEE International
Symposium on , p. 156, Aug. 1998.
[5] A. Ganz, A. Phonphoem, and Z. Ganz, “Robust superpoll protocol for ieee 802.11
wireless lans,” in Military Communications Conference, vol. 2, pp. 570–574, October
1998.
[6] S.-C. Lo, G. Lee, andW.-T. Chen, “An efficient multipolling mechanism for ieee 802.11
wireless lans,” IEEE Transactions on Computers, vol. 52, June 2003.
[7] R. Ranasinghe, L. Andrew, and D. Everitt, “Impact of polling strategy on capacity
of 802.11 based wireless multimedia lans,” in IEEE International Conference on Networks,
pp. 96–103, Sept. 1999.
[8] H.-Y. Wei, C.-C. Chiang, and Y.-D. Lin, “Co-drr: an integrated uplink and downlink
scheduler for bandwidth management over wireless lans,” in Proceedings. Eighth IEEE
International Symposium on Computers and Communication, pp. 1415–1420, June
2003.
[9] M. Shreedhar and G. Varghese, “Efficient fair queuing using deficit round robin,”
IEEE/ACM Transactions on Networking (TON), vol. 4, june 1996.
[10] M. Zorzi, R. R. Rao, and L. B. Milstein, “On the accuracy of a first-order Markov
Model for data transmission on fading channels,” in Proc. IEEE ICUPC, pp. 211–215,
Nov. 1995.
[11] “The Network Simulator - ns-2.” http://www.isi.edu/nsnam/ns/.
[12] ANSI/IEEE Std 802.11, “Wireless LAN medium access control (MAC) and physical
layer (PHY) specifications,” 1999.
[13] A. Chockalingam, M. Zorzi, R. R. Rao, “Performance of TCP on wireless fading links
with memory,” in Communications, 1998. ICC 98. Conference Record.1998 IEEE International
Conference on, pp. 595–600, Jun. 1998.

全文公開日期本全文未授權公開 (校內網路)
全文公開日期本全文未授權公開 (校外網路)

簡易檢索 / 詳目顯示

相關論文