近年來車輛的安全應用成為車載網路中重要的議題，如何透過多躍散佈緊急訊息成為了一個主要的課題。本篇論文我們設計一個十字路口緊急訊息廣播協定，透過蒐集傳輸者鄰居訊號強度資訊，並藉由訊號強度分析出個車輛訊號強度資訊，並透過車輛資訊達到動態區域切割，找出最佳的車輛做緊急訊息代傳，藉此避免廣播風暴的發生以及減少多躍散佈所耗費之時間。本論文重點在於安全訊息廣播，時間將會為重要參考因素，透過模擬分析來驗證本篇論文提出之廣播協議，在傳輸延遲以及傳輸成功率會有顯著的改善。

In recent years, vehicle safety application has played a more important role in Vehicle Ad-hoc NETwork (VANET). How to disseminate emergency message in a Multi-hop way becomes a major issue. In this paper, we propose an intersection emergency message broadcasting protocol. To do so can not only find the best vehicle in the furthest possible segment to relay the emergency messages in the network, but also can avoid broadcast storms and reduce end-to-end delay of the packet. This paper focuses on safety messages broadcast time. Through simulation analysis to validate the proposed broadcast protocol, significant improvements are available in the transmission delay and transmission success rates.

目錄
第1章	緒論	1
1.1	前言	1
1.2	研究動機與目的	2
1.3	研究方法	3
1.4	論文架構	4
第2章	相關知識	5
2.1	 問題描述	5
2.2	 近年來之研究	6
2.3相關文獻	9
第3章	預備知識	14
3.1	訊號計算	14
3.2	電力控制	15
3.2.1	車道車輛數的判定 15
3.2.1	透過抑制找出最遠車輛 18
第4章 隨意車載網路中城市道路之多步緊急訊息傳輸(Multi-hop Emergency Message Dissemination for Vehicular Ad Hoc Networks on Urban Roads )	20
4.1	基本理念	20
4.2	環境設定	21
4.2	路口廣播模式	23
4.3	Store-Carry-Forward	25
第5章	網路效能模擬	27
5.1 實驗場景及參數設定	27
5.2 實驗結果及分析	28
5.3.1 Total number of MAC-layer slots 28
5.3.2 Message Progress 29
5.3.3 Message dissemination speed 30
第6章	結論	32
參考文獻	33
附錄-中文論文	37
附錄-英文論文	45

圖目錄
圖 1：廣播風暴	5
圖 2：網路廣播延遲	6
圖 3：車載網路廣播分類	7
圖 4：UMB運行機制	11
圖 5：AMB運行機制	12
圖 6：BPAB運行機制	13
圖 7：Power control	16
圖 8：稀疏車輛數與擁塞車輛數	17
圖 9：車輛使用功率	17
圖 10：車輛稀疏車道	18
圖 11：車輛擁擠車道	19
圖 12：車輛擁擠車道	22
圖 13：場景設定	23
圖 14：RTB廣播	24
圖 15：Segment切割	25
圖 16：Four intersections 1800 m × 2400 m	27
圖 17：Total number of MAC-layer slots	29
圖 18：One hop message progress	30
圖 19：Message dissemination speed	31
 
表目錄
表  1：實驗的模擬參數設定	28

[1]J. B. Kenney, “Dedicated Short-Range Communications (DSRC) Standards in the United States,” in Proceedings of the IEEE, vol. 99, no. 7, pp. 1162-1182, Jun. 2011.
[2]IEEE Std. 802.11p-2010, Part11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, IEEE, Jul. 2010.
[3]IEEE Std. 802.11p-2010, Part11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, IEEE, Jul. 2012.
[4]X. Zhuo, S. Hua, L. Miao, and Y. Dai, “Direction Matters: A Decentralized Direction-based TDMA Scheduling Strategy for VANET,” IEEE International Conference on Communication Technology, pp.566-571, Sep. 2011.
[5]K. A. Hafeez, L. Zhao, Z. Liao, and B. N.-W. Ma, “A new broadcast protocol For Vehicular Ad hoc Networks Safety Applications,” in Proceedings of Global Communications Conference, pp.1-5, Dec. 2010.
[6]S. Oh, M. Gruteser, D. Pompili, “Coordination-free safety messages Dissemination Protocol for Vehicular Network,” IEEE Transactions on Vehicular Technology, pp. 1-13, May. 2012.
[7]Y. Bi, L. X. Cai, X. Shen, H. Zhao, “Efficient and reliable broadcast in intervehicle communication networks: a cross-layer approach,” IEEE Transactions on Vehicular Technology, vol. 59, no. 5, pp.2404-2417, Jun. 2010.
[8]I.-C. Chang, Y.-F. Wang, and C.-F. Chou, “Efficient VANET unicast routing using historical and real-time traffic information,” in Proceedings of the International Conference on Parallel and Distributed Systems, pp.1-7, 2011.
[9]Y.-B. Wang, T.-Y. Wu, W.-T. Lee, and C.-H. Ke, “A novel geographic routing strategy over VANET,” in Proceedings of the International Conference on Advanced Information Networks and Applications Workshops, 2010, pp. 1–7.
[10]X. Yu, H. Guo, and W.-C. Wong, “A reliable routing protocol for VANET communications,” in Proceedings of the International Conference on Wireless Communications and Mobile Computing Conference, 2011, pp. 1–6.
[11]M. M. Bhuiyan and S. M. Salim, “Density aware broadcasting scheme for VANET,” in Proceedings of the Asia-Pacific Conference on Communications, 2011, pp. 1–5.
[12]Q. Yu and G. Heijenk, “Abiding geocast for warning message dissemination in vehicular ad hoc networks,” in Proceedings of the International Conference on Communications Workshops, 2008, pp. 1–5.
[13]H.-C. Jang and H.-T. Huang, “Moving direction based greedy routing algorithm for VANET,” in Proceedings of the International Conference on Computer Symposium, 2010, pp. 1–6.
[14]E. Fasolo, A. Zanella, M. Zorzi, “An Effective Broadcast Scheme for Alert Message Propagation in Vehicular Ad hoc Networks,” in Proceedings of the International Conference on Communications, pp.1-6, 2006.
[15]N. Wisitpongphan, O. K. Tonguz, J. S. Parikh, P. Mudalige, F. Bai, and V. Sadekar, “Broadcast storm mitigation techniques in vehicular ad hoc networks,” IEEE Wireless Communications, December 2007, pp. 84–94.
[16]N. R, and K. Karuppanan, “Opportunistic Dissemination of Emergency Messages using VANET on Urban Roads,” IEEE International Conference on Recent Trends in Information Technology, pp.172-177, 2011.
[17]R. Chen, W.-L. Jin, A. Regan, and Irvine, “Broadcasting Safety Information in Vehicular Networks: Issues and Approaches,” IEEE Communications Society, pp.20-25, 2010.
[18]M.Chitra, S.S. Sathya, “Efficient Broadcasting Mechanisms for data Dissemination in Vehicular Ad Hoc Networks,” International Journal of Mobile Network Communications and Telematics, pp.47-63, June, 2013.
[19]L. Zhou, G. Cui, H. Liu, Z. Wu , and D. Luo, “NPPB: A Broadcast Scheme in Dense VANETs,” Information Technology Journal, pp.247-256, 2010.
[20]G. Tan, Y. Yin, J. Bu, and N. Ding, “An IVC Broadcast Scheme Based on Traffic Phase for Emergency Message Dissemination at Road Intersection,” International Conference on Complex, Intelligent, and Software Intensive Systems, pp.59-65, 2013.
[21]C. Suthaputchakun, Z. Sun, and M. Dianati, “Trinary Partition Black-Burst based Broadcast Protocol for Emergency Message Dissemination in VANET,” IEEE in Proceedings of Wireless Communications and Networking Conference, pp.2244-2249, Apr. 2013.
[22]G. Korkmaz, E. Ekici, F. Ozguner, and U. O‥ zgu‥ner, “Urban multihop broadcast protocol for inter-vehicle communication systems,” in Proceedings of the ACM Workshop on VANET, pp. 1-10, 2004.
[23]G. Korkmaz, E. Ekici, and F. Ozguner, “Black-Burst-Based Multihop Broadcast Protocols for Vehicular Networks,” IEEE transactions on vehicular technology, Vol. 56, NO.5, pp 3159-3167, Sep. 2007.
[24]J. Sahoo, H.-K. Wu, P. K. Sahu, and M. Gerla, “Binary-partition-assisted MAC-layer broadcast for emergency message dissemination in VANETs,” IEEE Transactions on Intelligent Transportation Systems, vol. 12, no. 3, pp.757-770, Sep, 2011.
[25]H. Wu, R. Fujimoto , R. Guensler , and M. Hunter, “MDDV: A Mobility-Centric Data Dissemination Algorithm,” ACM International Workshop on Vehicular Ad Hoc Networks, Oct. 2004.
[26]Y.-T. Yang, and L.-D. Chou, “Position-based adaptive broadcast protocol for inter-vehicle communications,” in Proceedings of the International Conference on Communications Workshops, 2008, pp. 1–5.
[27]C.-Y. Yang, and S.-C. Lo, “Street Broadcast with Smart Relay for Emergency Messages in VANET,” IEEE International Conference on Advanced Information Networking and Applications Workshops, pp.823-828, 2010.