臺灣博碩士論文加值系統

無線網路的發展，從短距離個人無線網路技術(例如:802.15)到區域性的無線網路技術(例如:802.11)發展達到一個穩定狀態後；近年來，通信技術從傳統的 cable與 optical-based轉向無線寬頻技術快速的發展，此技術的設計多被應用在移動式的傳輸中與需要較大傳輸需求者上，像是語音通訊、 家用多媒體技術、遠端搖控與監測、 信用卡驗證機制、emergency service support， 等多類的傳輸中。在無線寬頻的存取技術中，IEEE 802.16的protocol是一個重要的議題，規定了在這個傳輸架構下(Wireless Metropolitan Area Network)，所有的傳輸者與基地台之間的傳輸方式。
本文提出一個應用於IEEE 802.16 mesh網路的集中式(Centralized) 排程演算法，此方法將傳輸資料的服務品質納入考量並且可以修正在Mesh網路中傳輸節點實際上可以允許存取通道但卻無法被排程的問題，並且將排程的使用延伸到downstream的方向中，模擬針對Scheduling length、Channel Utilization Ratio、Delay time三項結果顯示本研究所提之方法可以提供較好的排程的結果，並且可以提昇IEEE 802.16 mesh網路的通道使用率。

Rapid advances in the mobile communications and wireless technology fields in recent decades have prompted a move away from traditional cable- and optical-based networks toward broadband wireless networks designed to support such diverse applications as voice communications, home computing, remote surveillance and monitoring, credit card verification, emergency service support, and so forth. The broadband wireless access of IEEE 802.16 protocol introduces an important issue for bandwidth usage of subscriber stations in Wireless Metropolitan Area Network. This paper proposes a centralized node-based transmission tree scheduling (n-TTS) algorithm for IEEE 802.16 mesh networks. The proposed algorithm takes the effects of channel interference into account and is designed to improve both the channel utilization ratio and the QoS performance of the mesh network. The simulation results confirm that n-TSS achieves a shorter transmission delay time than the link-based TTS scheme and yields a significant improvement in the channel utilization ratio.

Chapter 1 Introduction ..........................................................................................1
1.1 Overview .....................................................................................................1
1.2 Motivation ...................................................................................................4
1.3 Objective ......................................................................................................4
1.4 Dissertation Outline ................................................................................5
Chapter 2 Background ............................................................................................6
2.1 Broadband Wireless Access ..........................................................................6
2.2 IEEE 802.16 Standard Introduction .............................................................6
2.3 IEEE 802.16 Scheduling ..............................................................................8
2.4 Related Work .............................................................................................11
2.5 Summary ....................................................................................................15
Chapter 3 Node-base Transmission Tree Scheduling Algorithm ........................16
3.1 Problem definitions and Symbol definitions ................................................16
3.2 N-TTS Algorithm Introduction ...................................................................17
3.3 N-TTS Upstream .......................................................................................21
3.4 N-TTS Downstream ...................................................................................25
3.5 N-TTS Downstream & Upstream output ....................................................29
3.6 Summary ....................................................................................................31
Chapter 4 N-TTS Performance Evaluation .........................................................32
4.1 Simulation Environment & Software ..........................................................33
4.2 Scheduling Length ......................................................................................35
4.3 Channel Utilization Ratio ............................................................................37
4.4 Delay time ..................................................................................................39
4.5 Summary ....................................................................................................41
Chapter 5 Conclusion ............................................................................................42
Reference ................................................................................................................43

[1]IEEE Std. 802.16-2004, "IEEE Standard for Local and Metropolitan Area Networks-Part 16: Air Interface for Fixed Broadband Wireless Access Systems," October 2004.
[2]IEEE Std. 802.16e/D9-2005, "IEEE Standard for Local and Metropolitan Area networks – Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems, Amendment 2: Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands and Corrigendum 1," February 2006.
[3]H. Shetiya, and V. Sharma, "Algorithms for Routing and Centralized Scheduling to Provide QoS in IEEE 802.16 Mesh Networks," ACM workshop on Wireless multimedia networking and performance modeling (WMuNeP), pp 140–149, October 2005.
[4]H.Y. Wei, S. Ganguly, R. Izmailov, and Z. Haas, "Interference-Aware IEEE 802.16 WiMAX Mesh Networks," IEEE Vehicular Technology Conference (VTC), Vol. 5, pp 3102–3106, May 2005.
[5]L. Fu Z. Cao P. Fan, "Spatial Reuse in IEEE 802.16 Based Wireless Mesh Networks," IEEE International Symposium on Communications and Information Technology (ISCIT), pp 1358–1361, October. 2005.
[6]J. Tao F. Liu Z. Zeng Z. Lin, "Throughput Enhancement in WiMax Mesh Networks Using Concurrent Transmission", Wireless Communications, Networking and Mobile Computing, pp 871–874, September 2005.
[7]J. Chen, C. Chi, and Q. Guo,"An Odd-Even Alternation Mechanism for Centralized Scheduling in WiMAX Mesh Networks", IEEE Global Telecommunications Conference (GLOBECOM), pp 1–6, November 2006.
[8]B. Han, W. Jia, L. Lin, "Performance Evaluation of Scheduling in IEEE 802.16 Based Wireless Mesh Networks", IEEE International Conference on Mobile AdHoc and Sensor Systems (MASS), pp789–794, October 2006.
[9]Y. Xu, Z.T. Li, X.F Zhong, H.M. Xu,"A Bandwidth Scheduling Algorithm Based on Minimum Interference Traffic in Mesh Mode", International Conference on Wireless Communications, Networking and Mobile Computing, pp 822–825, September 2007.
[10]B. Han, W. Jia, L. Lin, "Performance Evaluation of Scheduling in IEEE 802.16 Based Wireless Mesh Networks", Computer Communications, Vol. 30, No. 4, pp 782–792, February 2007.
[11]K. P Shin, "A Spatial Reuse Enhanced Centralized Minislot Scheduling for IEEE 802.16 Wireless Mesh Networks", International Computer Symposium, pp 13-15, November 2008.
[12]J. Najjar, B. Jaumard,C. Assi, "Minimizing Interference in WiMax/802.16 Based Mesh Networks with Centralized Scheduling" Telecommunications Conference, pp 1-6, November 2008.
[13]A. A. Hemyari,K. Ng Chee , K. N. Nor, A. Ismail and S. Khatun, "Constructing Routing Tree for Centralized Scheduling using Multi-Channel Single Transceiver System in 802.16 Mesh Mode" RF and Microwave Conference,pp 192 – 196, 2-4 Dec. 2008 .
[14]A. Ghiamatyoun, M. Nekoui,N. E. Said, M. Soltan, "Efficient Routing Tree Construction Algorithms for Multi-Channel WiMax Networks ",Computer Communications and Networks ,pp 957-960, 13-16 Aug. 2007.
[15]M. Cao, V. Raghunathan, P. R. Kumar,"A Tractable Algorithm for Fair and Efficient Uplink Scheduling of Multi-hop WiMax Mesh Networks" , Wireless Mesh Networks, pp 93-100, 25-28 Sept. 2006.
[16]D. Ghosh,A. Gupta, P. Mohapatra , " Admission Control and Interference-Aware Scheduling in Multi-hop WiMAX Networks" ,Mobile Adhoc and Sensor Systems, pp 1-9, 8-11 Oct. 2007.
[17]Z. Liu, M. Yang, J. Dai," Performance Improvement Based on Path Delay Analysis in WiMax Mesh Networks", Communications and Networking in China, pp 958-962, 22-24 Aug. 2007.
[18]P. Du, W. Jia, L. Huang , W. Lu, "Centralized Scheduling and Assignment in Multi-Channel Single-Transceiver WiMax Mesh Network", Wireless Communications and Networking Conference,pp 1734-1739, 11-15 March 2007.
[19]Y. Lu , G. Zhang ,"Maintaining Routing Tree in IEEE 802.16 Centralized Scheduling Mesh Networks ",Computer Communications and Networks,pp 240-245, 13-16 Aug. 2007.
[20]Q. Xiong , W. Jia , C. Wu,"Packet Scheduling Using Bidirectional Concurrent Transmission in WiMAX Mesh Networks", Wireless Communications Networking and Mobile Computing,pp2037-2040, 21-25 Sept. 2007 .
[21]F. Jin, A. Arora, J. Hwang, H. A. Choi," Routing and Packet Scheduling in WiMAX Mesh", Broadband Communications Networks and Systems, pp 574-582, 10-14 Sept. 2007.
[22]R. S. Cheng , D. J. Deng ,C. F. Liu, T. F. Yang," A Tree-based Scheduling Mechanism for IEEE 802.16 Mesh Networks ", International Symposium On Digital Life Technology, 28-29 May. 2009.
[23]E. N. Jad, B. Jaumard , C. Assi, " Efficient routing in WiMax/802.16 based mesh networks with centralized scheduling",Computers and Communications, pp 265-271, 6-9 July 2008.
[24]X. Li, X. Wu, W. Li , Y. Zhang, "An Efficient Packet Scheduling Algorithm for IEEE 802.16 BWA System",Wireless Communications Networking and Mobile Computing, pp 1-5, 12-14 Oct. 2008.
[25]H. L. Tseng, Y. P. Hsu, C. H. Hsu, P. H. Tseng, K. T. Feng, "A Maximal Power-Conserving Scheduling Algorithm for Broadband Wireless Networks",pp 1877-1882, March 31 2008-April 3 2008.
[26]E. N. Jad,B. Jaumard, C. Assi, "Maximizing Network Stability in a Mobile WiMax/802.16 Mesh Centralized Scheduling",Networking and Communications, pp 259-265. 12-14 Oct. 2008 .
[27]N.A. Abu Ali, A.M. Taha, H.S. Hassanein, and H.T. Mouftah, " IEEE 802.16 Mesh Schedulers: Issues and Design Challenges ", Network, IEEE,pp 58-65, Jan.-Feb. 2008.
[28]M. Guizani, P. Lin, S. M. Cheng, D. W. Huang , H. L. Fu," Performance Evaluation for Minislot Allocation for Wireless Mesh Networks ", IEEE Transactions on Vehicular Technology ,pp 3732-3745, Nov. 2008.
[29]T. Y. Tsai; Z. Tsai, " Design of a Packet Scheduling Scheme for Downlink Channel in IEEE 802.16 BWA Systems", Wireless Communications and Networking Conference,pp 1453-1458, March 31 2008-April 3 2008.
[30]E. Laias, I. Awan, P. ML. Chan," An Integrated Uplink Scheduler in IEEE 802.16",Computer Modeling and Simulation, pp 518-523, 8-10 Sept. 2008.
[31]S. Xergias, N. Passas, A.K. Salkintzis," Centralized Resource Allocation for Multimedia Traffic in IEEE 802.16 Mesh Networks",Proceedings of the IEEE,pp 54-63, Jan. 2008.
[32]M.H.M. Algamali, J. Wang, M. Y. Abdullah, "OBSS: Optimal Base Station Scheduler of IEEE 802.16 Mesh mode", Wireless Communications Networking and Mobile Computing, pp 1-4, 12-14 Oct. 2008.
[33]P. S. Mogre, N. d'Heureuse, M. Hollick, R. Steinmetz, "CORE: centrally optimized routing extensions for the IEEE 802.16 Mesh mode",Local Computer Networks, pp 58-65, 14-17 Oct. 2008 .
[34]S. Y. Wang , C. C. Lin , K. H. Fang , "Improving the Data Scheduling Efficiency of the IEEE 802.16(d) Mesh Network" ,Global Telecommunications Conference, pp 1-5, Nov. 30 2008-Dec. 4 2008
[35]L.W. Chen , Y. C. Tseng, D. W. Wang , J. J. Wu ,"Exploiting Spectral Reuse in Resource Allocation, Scheduling, and Routing for IEEE 802.16 Mesh Networks", Vehicular Technology Conference, pp1608-1612 , Sept. 30 2007-Oct. 3 2007.
[36]Dev C++, http://www.bloodshed.net/devcpp.html.