第五章 結論與未來研究
5.2 未來研究
國
立 政 治 大 學
‧
Na tiona
l Ch engchi University
第五章 結論與未來研究
5.1 結論
在本篇中所提出的架構，可以整合不同的繞徑協定，增加車用無線移動網路繞徑功能的 效率。經由實驗結果證明，當車輛所行駛的網路環境，不利於任何單一的繞徑協定方法，
並嚴重影響傳輸效能時，如果有另外一種方法，對於相同的環境其效能較不受影響，取 代原來的繞徑方法來傳遞封包，將可以有效地維持節點資料傳送的效能。
將數個繞徑模組整合在節點中，藉由各繞徑協定規畫封包的傳遞路徑，再根據節點 網路階層提供的資訊，用以選擇其中最佳的模組來傳遞封包，降低車輛在行經不同道路 環境時對單一繞徑方法可能造成的衝擊。另一方面，搭配數個繞徑模組可以讓原先的規 劃路徑，在封包傳遞過程中發生中斷時，能以另外一種繞徑方法所規劃的路徑，繼續完 成封包的傳遞，減少來源端需要對資料封包重新傳送的機會。同時為了減輕因為多重繞 徑方法而產生過多的網路負載(overloading)，我們採用封包列車的方式來整合繞徑封包，
減輕繞徑封包數量的影響。
5.2 未來研究
在車用無線網路繞徑問題上，我們提供了一個解決的方向，讓多個繞徑協定能整合 在一個架構下。然而，比起單一的繞徑協定，這樣的架構需要更多的運算能力或功耗，
才能同時處理各種繞徑及選徑的運算。但我們相信，未來這一部分的硬體需求在車用環
‧
國立 政 治 大 學
‧
Na tiona
l Ch engchi University
境上，應該不會是問題。相對的，如果要充分利用各個繞徑方法的優勢，還有賴於我們 對於各繞徑路徑的效能，以及在不同的環境中的交互關係，有更多量化的研究，才能提 升對路徑預測模式的準確度，讓整合式的架構效能有所提升。
另外，在無線移動隨意網路的領域裡，大部分的繞徑方法都會以跨層式的設計來改 良，但這些方式卻缺少共通的標準介面，來組織各個跨層元件之間的交互作用，定義及 整合有別於傳統節點架構的跨層式介面，避免各個單元重複建置相同的功能。這對於我 們提出的整合式架構來說，會是一個未來發展重要的課題。
最後，我們可預期利用多重繞徑整合，將可以提供一個具有擴充性的架構。有別於 當一個新的繞徑方法被提出時，必須將網路上所有節點的繞徑模組都更新後，才能在節 點之間傳遞封包，整合式的架構容許將新的繞徑協定整合至網路上的部分節點，便能與 現有的其他節點傳遞封包。
圖 5.1 不同繞徑方法混和的車用網路。
如圖 5.1，紅色的車輛代表可以用新的繞徑方法來傳遞封包的節點，綠色的車輛則 為只能使用現有方法的節點。當這些節點在同一個網路中，若來源節點與目的節點之間 存在以新的方法找尋的路徑，則封包以新的節點傳送，而同時，由於新的節點可以用現
‧
國立 政 治 大 學
‧
Na tiona
l Ch engchi University
有的繞徑方法，因而新的節點的加入並不會影響原來的網路效能。相信利用這種特性，
可以有助於當車用網路商業化之後，對於繞徑問題得以漸進式的方式來改良繞徑方法，
逐步更新節點至網路中，與現有的節點並存，以達到整體網路的提升。
‧
Mobility Model," in Proceedings of the 2010 Ninth International Conference on Networks(ICN '10). IEEE Computer Society, Washington, DC, USA, pp. 243-248.
[2] F. Bai and A. Helmy, “The IMPORTANT Framework for Analyzing and Modeling the Impact of Mobility in Wireless Adhoc Networks,” Wireless Ad Hoc and Sensor Networks, Kluwer Academic Publishers, 2004.
[3] J. Bernsen and D. Manivannan, "Routing Protocols for Vehicular Ad Hoc Networks That Ensure Quality of Service," in Proceedings of the 2008 The Fourth International
Conference on Wireless and Mobile Communications (ICWMC '08). IEEE Computer
Society, Washington, DC, USA, pp. 1-6.[4] N. Brahmi, M. Boussedjra, J. Mouzna, and B. Mireille, “Adaptative Movement Aware Routing for Vehicular Ad Hoc Networks,” in Proceedings of the 2009 International
Conference on Wireless Communications and Mobile Computing: Connecting the World Wirelessly (IWCMC '09), Leipzig, Germany, pp. 1310-1315.
[5] J. Broch, D. A. Maltz, D. B. Johnson, Y. Hu, and J. Jetcheva, “A Performance Comparison of Multi hop Wireless Adhoc Network Routing Protocols,” in Proceedings of the 4th
Annual ACM/IEEE International Conference on Mobile Computing and Networking
(MobiCom '98), Dallas, USA, 1998, pp. 85-97.[6] Y. Chen, Z. Xiang, W. Jian, and W. Jiang, "A Cross-Layer AOMDV Routing Protocol for V2V Communication in Urban VANET," in Proceedings of the 2009 Fifth International
Conference on Mobile Ad-hoc and Sensor Networks (MSN '09), IEEE Computer Society,
Washington, DC, USA, pp. 353-359.[7] D. R. Choffnes and F. E. Bustamante, ”An Integrated Mobility and Traffic Model for
‧
Vehicular Wireless Networks,” in Proceedings of the 2nd ACM international Workshop
on Vehicular Ad Hoc Networks, Cologne, Germany, 2005, pp. 69-78.
[8] B. Divecha, A. Abraham , C. Grosan, and S. Sanyal, “Impact of Node Mobility on MANET Routing Protocols Models,” Journal of Digital Information Management, vol. 5, no 1, pp. 19-24, Feb. 2007.
[9] J. Eriksson, H. Balakrishnan, and S. Madden, "Cabernet: Vehicular Content Delivery Using WiFi," in Proceedings of the 14th ACM International Conferenceon Mobile
Computing and Networking (MobiCom '08), San Francisco, USA, 2008, pp. 199-210.
[10] H. Füßler, M. Mauve, H. Hartenstein, M. Käsemann, and D. Vollmer, “A Comparison of Routing Strategies for Vehicular Ad-hoc Networks,” Department of Computer Science,
University of Mannheim, Tech. Rep. TR-02-003, July 2002.
[11] J. Härri, F. Filali, and C. Bonnet, “Mobility Models for Vehicular Ad Hoc Networks: a Survey and Taxonomy,” Communications Surveys & Tutorials, IEEE, vol.11, no.4, pp.19-41, Fourth Quarter 2009.
[12] F. Hui, “A Survey on the Characterization of Vehicular Ad Hoc Networks and Routing Solutions,” ECS 257, 2005.
[13] B. Jarupan and E. Ekici, “A Survey of Cross-Layer Design for VANETs,” Ad Hoc
Networks, vol. 9, no. 5, July 2011.
[14] B. Jarupan and E. Ekici, "PROMPT: A Cross Layer Position-based Communication Protocol for Delay-aware Vehicular Access Networks," Ad Hoc Networks, vol. 8, no. 5, pp.
489-505, July 2010.
[15] B. Karp and H. T. Kung, “GPSR: Greedy Perimeter Stateless Routing for Wireless Networks,” in Proceedings of the 6th Annual International Conference on Mobile
Computing and Networking (MobiCom '00), Boston, USA, 2000, pp. 243-254.
[16] A. Mahajan, N. Potnis, K. Gopalan, and A. Wang, ”Evaluation of Mobility Models for
‧
Vehicular Ad-hoc Network Simulations,” IEEE International Workshop on Next
Generation Wireless Networks (WoNGeN 2006), Bangalore, India, December 2006.
[17] V. Naumov, R. Baumann, and T. Gross, “An Evaluation of Inter-vehicle Ad Hoc Networks Based on Realistic Vehicular Traces,” in Proceedings of the 7th ACM
International Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc '06),
Florence, Italy, 2006, pp. 108–119.[18] S. Y. Ni, Y.C. Tseng, Y. S. Chen, and J. P. Sheu, “The Broadcast Storm Problem in a Mobile Ad Hoc Network,” in Proceedings of the 5th Annual ACM/IEEE International
Conference on Mobile Computing and Networking (MobiCom '99), Seattle, USA, 1999,
pp. 151-162.[19] Z. Niu, W. Yao, Q. Ni, and Y. Song, "Study on QoS Support in 802.11e-based Multi-hop Vehicular Wireless Ad Hoc Networks," in Proceedings of 2007 IEEE International
Conference on Networking, Sensing and Control, April, 2007, pp. 705-710.
[20] R. W. Rothery, “Car Following Models,” Traffic Flow Theory, Transportation Research Board Special Report 165, Chapter 4, 1992.
[21] A. K. Saha and D. B. Johnson, “Modeling Mobility for Vehicular Ad Hoc Networks,” in
Proceedings of the 1st ACM International Workshop on Vehicular Ad Hoc Networks,
Philadelphia, USA, 2004, pp. 91-92.[22] J. P. Singh, N. Bambos, B. Srinivasan, and D. Clawin, "Cross-layer Multi-hop Wireless Routing for Inter-vehicle Communication,” in Proceedings of TRIDENTCOM 2006 2nd
International Conference on Testbeds and Research Infrastructures for the Development of Networks and Communities, 2006, pp.10 pp. -101.
[23] I. Stojmenovic, "Position-based Routing in Ad hoc Networks," Communications
Magazine, IEEE, vol. 40, no. 7, pp. 128-134, July 2002.
[24] J. Wang and W. Yan, "RBM: A Role Based Mobility Model for VANET," in Proceedings
‧
國立 政 治 大 學
‧
Na tiona
l Ch engchi University
of the 2009 WRI International Conference on Communications and Mobile Computing - Volume 02 (CMC '09), vol. 2, IEEE Computer Society, Washington, DC, USA, pp.
437-443.
[25] "Simulation of Urban MObility" (SUMO) Open Source Project. Activity-Based Traffic Demand Using ActivityGen [Online]. Retrieved:
http://sourceforge.net/apps/mediawiki/sumo/index.php?title=Activity-Based_Traffic_De mand_Using_ActivityGen, June 2011.