無線網狀網路(Wireless Mesh Networks)拓展了無線區域網路的涵蓋範圍限制，提供大量的使用者封包經由網狀網路路由器多跳的轉送來存取網際網路。然而在這樣的環境下，使用者的經驗品質(QoE)卻會因所在位置及周邊的網路流量而產生明顯的差異。先前的研究探討了此環境中的問題，並提出使用頻道存取控制(channel access)或佇列管理(queue management)方式來解決流量非公平性問題，但這些頻寬分配的方式卻無法針對即時性的應用做出較好的服務。在本篇論文中，我們考慮使用即時性應用及盡力傳送應用特性的差別，並在由IEEE 802.11e構成的無線網狀網路環境中提出採比例原則並考慮延遲限制之頻寬分配方法，以提高使用者的經驗品質。在論文中，我們提供方法的分析模型及和相關文獻的完整比較。透過實驗數據和分析顯示，經由我們提出的方法可解決流量不公平的問題並且提升使用者經驗品質。

Wireless Mesh Networks (WMNs) extends the limited transmission coverage of Wireless LAN. Users could connect to the Internet by multi-hop relay from wireless mesh routers. However, the Quality of Experience (QoE) of users in different locations or with varied traffic loading is distinct in such multi-hop WMNs. Prior researches have pointed out the unfair phenomena and given solutions to this issue. Although these schemes based on channel access or queue management achieve throughput fairness among users, the delay and bandwidth may not conform to the requirements of real-time applications because the channel resource are fairly shared to all uses. In this thesis, we consider the difference in playout systems between best-effort service and real-time applications. A proportional bandwidth allocation considering delay constraint is proposed to enhance the QoE of users for wireless mesh networks using the IEEE 802.11e standard. Analytical model of the proposed scheme and comprehensive comparison among related researches are given. From the simulation results, the proposed scheme outperforms previously proposed schemes for various performance metrics.

[1] R. Hiertz, et al., “IEEE 802.11s: the WLAN Mesh Standard,” IEEE Wireless Communications, Volume 17, Issue 1, Page 104-111, 2010
[2] S. Xu and T. Saadawi, “Does the IEEE 802.11 MAC protocol work well in multihop wireless ad hoc networks?,” IEEE Communications Magazine, Volume 39, Issue 6, Page 130-137, 2001
[3] H. Hsieh and R. Sivakumar, “IEEE 802.11 over multi-hop wireless networks: problems and new perspectives,” IEEE Vehicular Technology Conference, Page 748-752, 2002
[4] A .Raniwala, et al., “End-to-End Flow Fairness over IEEE 802.11-based Wireless Mesh Networks,” IEEE International Conference on Computer Communications, Page 2361-2365, 2007
[5] G.Hiertz, et al., “IEEE 802.11s – Mesh Deterministic Access,” European
Wireless Conference, Page 1-8, 2008
[6] IEEE Standard for Information Technology - Telecommunications and Information Exchange Between Systems - Local and Metropolitan Area Networks - Specific Requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 8: Medium Access Control (MAC) Quality of Service Enhancements, IEEE Standard, 2005
[7] S. Lee and C. Yoo, “Hop-Based Priority Technique Using 802.11e for Multimedia Streaming,” IEEE Transactions on Consumer Electronics, Volume 56, Issue 1, Page 48-53, 2010
[8] Y. Bae, et al., “Packet management scheme for location-independent end-to-end delay in IEEE 802.11s multi-hop wireless mesh networks,” International Conference on Telecommunications, Page 1-8, 2008
[9] J. Li, et al., “Adaptive per hop differentiation for end-to-end delay assurance in multihop wireless networks,” ACM Ad Hoc Networks, Volume 7, Issue 6, 2009
[10] M. Kim, et al., “EDCA-TM: IEEE 802.11e MAC Enhancement for wireless Multi-hop Networks,” IEEE Wireless Communications and Networking Conference, Page 1-6, 2009
[11] K. Wakuda, et al., “A Packet Scheduling Algorithm for Max-min Fairness in Multihop Wireless LANs,” ACM Computer Communications, Volume 32, Issue 13-14, 2009
[12] N. Nandiraju, et al., “Service Differentiation in IEEE 802.11s Mesh Networks: A Dual Queue Strategy,” IEEE Military Communication Conference, Page 1-7, 2007
[13] L. Romdhani, et al., “Adaptive EDCF: Enhanced Service Differentiation for IEEE 802.11 Wireless Ad-Hoc Networks,” IEEE Wireless Communications and Networking Conference, Page 1373-1378, 2003
[14] V. Siris, et al., “Optimal CWmin Selection for Achieving Proportional Fairness in Multi-Rate 802.11e WLANs: Test-bed Implantation and Evaluation,” ACM International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization, Page 41-48, 2006
[15] S. Nahle, et al., “Graph-based Approach for Enhancing Capacity and Fairness in Wireless Mesh Networks,” IEEE Global Telecommunications Conference, Page 1-7, 2009
[16] M. Razzaque, et al., “Aggregated traffic flow weight controlled hierarchical MAC protocol for wireless sensor networks,” Annals of Telecommunications, Volume 64, Page 705-721, 2009
[17] J. Lee, et al., “Distributed Fair Scheduling for Wireless Mesh Networks Using IEEE 802.11,” IEEE Transaction on Vehicular Technology, Volume 59, Issue 9, Page 4467-4475, 2010
[18] T. Li, et al., “Achieving End-to-end Fairness in 802.11e Based Wireless Multi-Hop Mesh Networks without Coordination,” ACM Mobile Networks and Applications, Volume 16, Issue 1, Page 17-34, 2011
[19] X. Chu, “Provisioning of Parameterized Quality of Service in 802.11e Based Wireless Mesh Networks,” ACM Mobile Networks and Applications, Volume 13, Issue 1-2, Page 6-18, 2008
[20] A. Raniwala and T. Chieh, “Architecture and Algorithms for an IEEE-802.11-based Multi-channel Wireless Mesh Network,” IEEE INFOCOM 24th Annual Joint Conference of the IEEE Computer and Communications Societies, Page 2223-2224, 2005
[21] J. Lee, et al., “An Incentive-Based Fairness Mechanism for Multi-hop Wireless Backhaul Networks with Selfish Nodes,” IEEE Transactions on Wireless Communications, Volume 7, Issue 2, Page697-704, 2008
[22] G. Bianchi, “Performance Analysis of the IEEE 802.11 Distributed Coordination Function,” IEEE Journal on Selected Areas in Communications, Volume 18, Issue 3, Page 535-547, 2000
[23] C. Huang and W. Liao, “Throughput and Delay Performance of IEEE 802.11e Enhanced Distributed Channel Access (EDCA) Under Saturation Condition,” IEEE Transaction on Wireless Communications, Volume 6, Issue 1, Page 136-145, 2007
[24] “YUV video sequences (QCIF), http://www.tkn.tu-berlin.de/reserach/evalvid/qicf.html”
[25]”ffmpeg, http://ffmpeg.source forge.net/index.php”
[26] “ITU-T Recommendation G.114, http://eu.sabotage.org/www/ITU/G/G0114e1.pdf”
[27] “Understanding Delay in Packet Voice Networks, CISCO document ID 5125, http://www.cisco.com/en/US/tech/tk652/tk698/technologies_white_paper09186a00800a8993.shtml”
[28] T. Stockhammer, et al., “H.264/AVC Video for Wireless Transmission,” IEEE Wireless Communications, Volume 12, Issue 4, Page 6-13, 2005
[29] T. Liu and W. Liao, “Location-Dependent Throughput and Delay in Wireless Mesh Networks,” IEEE Transactions on Vehicular Technology, Volume 57, Issue 2, Page 1188-1198, 2008.
[30] R. Carrano, et al., “IEEE 802.11s Multihop MAC: A Tutorial,” IEEE Communications Surveys & Tutorials, Volume 13, Issue 1, Page 56-67, 2011
[31] W. Conner, et al., “IEEE 802.11s Tutorial Overview of the Amendment for Wireless Local Area Mesh Networking, http://www.ieee802.org/802_tutorials/06-November/802.11s_Tutorial_r5.pdf,” IEEE 802 Plenary, 2006