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| Title: | 無線網狀網路多元速率下的多跳接路徑容納量與延遲之研究與分析
A Study on Multi-rate Multi-hop Path Capacity and Delay in Wireless Mesh Networks |
| Authors: | 蔡承璋
Tsai, Cheng-Chang |
| Contributors: | 蔡子傑
Tsai, Tzu-Chief
蔡承璋
Tsai, Cheng-Chang |
| Keywords: | 無線網狀網路
多元速率
多跳接
802.11
wireless mesh network
multirate
multihop
802.11 |
| Date: | 2007 |
| Issue Date: | 2010-12-08 12:01:13 (UTC+8) |
| Abstract: | 近年來興起一個前瞻性無線技術，稱之為無線網狀網路（Wireless Mesh Networks；WMNs） 以所費低廉方式提供無線網路最後一哩存取Internet，同時具備ad hoc網路全部優點。例如自我組織（self-organization）、自我組態（self-configuration）等。而802.11協議已經納入802.11s草案。雖然802.11的實體層支持多元速率，大多數研究為了簡化多假設在單一速率的情況下。但事實上，802.11可以支援的Automatic Rate Fallback (ARF)多元速率演算法；換句話說，由於信號雜訊比和資料錯誤率的不同，資料傳輸速率將自動調整。在這裡，我們假定在WMNs上使用 802.11協定，並且考慮路徑容量，延遲，流量公平及多元速率多跳接的環境。為了設法指出和改善這方面的議題，我們提出了經由改進802.11競爭視窗和加權公平調度機制的跨階層設計。透過一系列的模擬指出問題並找出合適的解決方案。結果顯示，如果增加低速率連結的優先權和考慮流量公平問題，容量及延遲將得到改善。
A new promising wireless technology has emerged recently, called wireless mesh networks (WMNs). WMNs are an inexpensive way to provide wireless last-mile broadband Internet access and have all the advantages of ad hoc networks, such as self-organization, self-configuration. IEEE 802.11 MAC protocol has been adopted in 802.11s draft. Although IEEE 802.11 physical layer supports multiple rates, most researches assume single rate environment for simplicity. However, in reality, 802.11 adopts automatic rate fallback (ARF) multi-rate algorithm. In other words, the data rate will be automatically adjusted due to its signal-to-noise ratio, or error rate. Here, we assume the fitness of IEEE 802.11 over WMNs, and considering path capacity, delay, flow fairness, in multi-hop multi-rate environments. They all are affected by data rates on the links along the path. In order to address and improve the above issues, we propose a cross layer scheme which is modified by the contention window of IEEE 802.11 DCF MAC and weighted fairness scheduling mechanism. We point out the problem and find out the suitable solution via a series of scenarios simulations. The results show that if increasing the priority of the low data link and taking care about flow fairness problem, the capacity and delay will be improved. |
| Reference: | [1] V. Kanodia, C. Li, A. Sabharwal, B. Sadeghi, and E. Knightly, "Distributed Multi-Hop Scheduling with Delay and Throughput Constraints", Proceedings of ACM MOBICOM 2001, Rome, Italy, July, 2001.
[2] Anders Lindgren, Andreas Almquist and Olov Schel,”Evaluation of Quality of Service Schemes for IEEE 802.11 Wireless LANs”, In Proceedings of the 26th Annual IEEE Conference on Local Computer Networks (LCN 2001), November 15-16, 2001 Tampa, Florida, USA.
[3] Garcia-Macias .J.A, Rousseau .F, Berger-Sabbatel .G, Toumi .L, Duda .A, “Quality of Service and Mobility for the Wireless Interne”. (2001), First ACM Wireless Mobile Internet Workshop
[4] H. Aoki, N. Chari, L. Chu, W. S. Conner, S. M. Faccin, D. Gurevich, V.Hasty, J. Jetcheva, S. Kangude, S. Saito and R. Taori: “802.11 TGs Simple Efficient Extensible Mesh (SEE-Mesh) Proposal,” IEEE802.11 document 05/0562r0, Jul. 2005
[5] G. Tan and J. Guttag. Time-based Fairness Improves Performance in Multi-rate Wireless LANs. In Proc. of USENIX Annual Technical Conference, 2004.
[6] A. Kamerman and L. Monteban. WaveLAN II: A High-Performance Wireless LAN for the Unlicensed Band. Bell Labs Technical Journal, pages 118–133, 1997.
[7] Gavin Holland, Nitin Vaidya, and Paramvir Bahl. A Rate-Adaptive MAC Protocol for Multi-Hop Wireless Networks. In MobiCom ’01: Proceedings of the 7th annual international conference on Mobile computing and networking, pages 236–251, New York, NY, USA, 2001. ACM Press.
[8] B. Sadeghi, V. Kanodia, A. Sabharwal, and E. Knightly. Opportunistic Media Access for Multirate Ad Hoc Networks. In MobiCom ’02: Proceedings of the 8th annual international conference on Mobile computing and networking, pages 24–35, New York, NY, USA, 2002. ACM Press.
[9] Y.L. Kuo, K.W. Lai, F.Y.S. Lin, Y.F. Wen, H.K. Wu and G.H. Chen, 2005, "Multi-Rate Throughput Optimization for the Wireless Local Area Network Anomaly Problem", Proc. IEEE/CreateNet BROADNETS’05.
[10] http://www.qualnet.com/ |
| Description: | 碩士
國立政治大學
資訊科學學系
94971009
96 |
| Source URI: | http://thesis.lib.nccu.edu.tw/record/#G0094971009 |
| Data Type: | thesis |
| Appears in Collections: | [資訊科學系] 學位論文
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