車載無線通訊網路（Vehicular Ad-hoc Network，VANET）是一個在現今很先進也很有前景的科技。一般來說，車輛在傳遞封包的時候，會使用地域優先考量(Distance greedy)這一個方法來選擇下一個幫忙傳遞封包的車輛。然而這一個方法最大的缺點是，他只會考量當前最好的車輛來幫忙傳遞封包，而非整個環境的因素，因此，也許被選擇的車輛在未來可能會將封包帶離終點更遠的方向，甚至造成局部極大點(Local Maximum)的發生。有鑒於此，在這篇論文中，我們提出了一個方法為使用智慧導航系統(GPS)去取得車輛未來的移動方向，幫助我們選擇一台理想的車輛去幫忙傳遞封包，以減少消耗和改進傳遞封包的成功率。這篇論文主要的貢獻為提出一個方法，而這一個方法為考量車輛當前位置和未來移動軌跡，並把我們所提出的方法和地域優先考量(Distance greedy)做比較，比較他們的延遲時間、消耗和傳遞封包成功率。最後在這篇論文中我們驗證了，我們的方法在消耗和傳遞封包成功率上皆有比較傑出的表現。

Vehicular Ad Hoc Network (VANET) is nowadays an advanced and promising technology. Vehicular routing often using Distance-Greedy (Always choose the vehicle which is the nearest to the destination geographically in the transmission range.) way to select next-hop. However, the main problem of this method is that the method just consider next hop not the overall situation; therefore, perhaps the chosen next-hop’s future position is far away from the destination and even causes Local Maximum. Accordingly, the paper proposes the approach, using GPS (Global Position System) navigation to obtain vehicles’ future moving direction, to help us select an ideal relay to transmit the data in an effort to reduce the cost of VANET and to improve the transmission rate. The main contribution of the work is proposing the method, which considers vehicles’ position and future moving trajectory, and to analyze proposed method in comparison with Distance-Greedy in terms of delay time, cost and successful rate. Finally the paper validates proposed method shows good performances on cost and successful rate.

[1]. Pedro Gomes, Cristina Olaverri-Monreal, and Michel FerreiraMaking, “Vehicles Transparent Through V2V Video Streaming,” IEEE Trans. on Intelligent Trans. System, vol. 13, no. 2, Jun. 2012, pp. 930 – 938.
[2]. T.-H. Hsu, S.-I. Sou and C.-S. Lin, “Architecture and Recipient Selection of Emergency Messaging for Ambulance Traveling,” IEEE 79th Vehicular Technology Conference, May 2014.
[3]. Josiane Nzouonta, Neeraj Rajgure, Guiling (Grace) Wang, Member, IEEE, and Cristian Borcea, Member, IEEE, “VANET Routing on City Roads Using Real-Time Vehicular Traffic Information,” IEEE Trans. Veh. Technol., vol. 58, no. 7, Ssp. 2009, pp. 3609 – 3626.
[4]. Yasuharu OHTA, Tomoyuki OHTA, Eitaro Kohno, and Yoshiaki KAKUDA, “A Store-Carry-Forward-Based Data Transfer Scheme Using Positions and Moving Direction of Vehicles for VANETs,” 2011 10th International Symposium on Autonomous Decentralized Systems (ISADS), 23-27 Mar. 2011, pp. 131 – 138.
[5]. Gökhan Korkmaz, Eylem Ekici, Füsun Özgu¨ner and U¨mit Özgu¨ner, “Urban Multi-Hop Broadcast Protocol for Inter-Vehicle Communication Systems,” VANET '04 Proceedings of the 1st ACM international workshop on Vehicular ad hoc networks, pp. 76-85.
[6]. Jagruti Sahoo, Eric Hsiao Kuang Wu, Pratap Kumar Sahu and Mario Gerla, “BPAB: Binary Partition Assisted Emergency Broadcast Protocol For Vehicular ad hoc Networks,” 18th International Conference on Computer Communications and Networks, 3-6 Aug. 2009, pp. 1 – 6.

[7]. Chakkaphong Suthaputchakun, Zhili Sun, and Mehrdad Dianati, “Trinary Partition Black-Burst based Broadcast Protocol for Emergency Message Dissemination in VANET,” Wireless Communications and Networking Conference (WCNC), 2013 IEEE, 7-10 Apr. 2013, pp. 2244 – 2249.
[8]. Lars Wischhof and Hermann Rohling, “Congestion Control in Vehicular Ad Hoc Networks,” IEEE International Conference on Vehicular Electronics and Safety, 14-16 Oct. 2005, pp. 58 – 63.
[9]. Pei Huang, Chen Wang, and Li Xiao, Senior Member, IEEE, “Improving End-to-End Routing Performance of Greedy Forwarding in Sensor Networks,” IEEE Trans on Parallel and Distributed Systems, vol. 23, no. 3, Mar. 2012, pp. 556 – 563.
[10]. Trung-Tuan Luong, Boon-Chong Seet, and Bu-Sung Lee, “Local Maximum Avoidance with Correlated Street Blocking for Map-based Geographic Routing in VANETs,” 2nd International Symposium ISWPC 2007., 5-7 Feb. 2007.
[11]. Yongyi Zhao, Bo Song and Jin Li, “A Map Matching Algorithm in GPS-based Car Navigation System,” Third International Conference on IIHMSP 2007, 26-28 Nov. 2007, pp. 77 – 80.
[12]. Brad Karp and H. T. Kung, “GPSR: Greedy Perimeter Stateless Routing for Wireless,” MobiCom '00 Proceedings of the 6th annual international conference on Mobile computing and networking, pp. 243-254.
[13]. H.-C. Jang and H.-T. Huang, “Moving Direction Based Greedy Routing Algorithm for VANET,” International Computer Symposium (ICS), 16-18 Dec. 2010, pp. 535 – 540.
[14]. Jasmin Velagic, Nedim Osmic, Faris Hodzic, Harun Siljak, “Outdoor Navigation of a Mobile Robot Using GPS and GPRS Communication System,” ELMAR, 2011 Proceedings, 14-16 Sept. 2011, pp. 173 – 177.

[15]. Jing Zhao and Guohong Cao, “VADD: Vehicle-Assisted Data Delivery in Vehicular Ad Hoc Networks,” IEEE Vehicular Technology Conference, pp. 1910 – 1922.
[16]. Y.-B. Wang, T.-Y. Wu, W.-T. Lee, C.-H. Ke, “A Novel Geographic Routing Strategy over VANET,” IEEE 24th International Conference on Advanced Information Networking and Applications Workshops (WAINA), 20-23 Apr. 2010, pp. 873 – 879.
[17]. I.-C. Chang, H.-T. Tai, D.-L. Hsieh, F.-H. Yeh, S.-H. Chang, “Design and Implementation of the Travelling Time- and Energy-Efficient Android GPS Navigation App with the VANET-based A* Route Planning Algorithm,” IEEE 24th International Conference on Advanced Information Networking and Applications Workshops (WAINA), 20-23 Apr. 2010, pp. 873 – 879.
[18]. Daniel Krajzewicz, Jakob Erdmann, Michael Behrisch, and Laura Bieker, “Recent Development and Applications of SUMO – Simulation of Urban Mobility,” International Journal on Advances in Systems and Measurements, vol 5 no 3 & 4, year 2012, http://www.iariajournals.org/systems_and_measurements/.
[19]. Rahul C. Shah, Sven Wieth¨olter, Adam Wolisz, Jan M. Rabaey, “When Does Opportunistic Routing Make Sense?,” IEEE 3th International Conference on Pervasive Computing and Communications Workshops, 2005, 8-12 Mar. 2005, pp. 350 – 356.
[20]. Holger F€ußler, J€org Widmer, Michael K€asemann, Martin Mauve, Hannes Hartenstein, “Contention-based forwarding for mobile ad hoc networks,” Ad Hoc Networks Volume 1, Issue 4, Nov. 2003, pp. 351–369.
[21]. Pavel Moiseets and Yuzuru Tanaka, “Road Danger Estimation for Winter Road Management,” 2014 International Conference on Cyber-Enabled Distributed Computing and Knowledge Discovery, pp. 304 – 311.

[22]. Rupesh Kumar and S. V. Rao, “Directional Greedy Routing Protocol (DGRP) in Mobile Ad-hoc Networks,” International Conference on Information Technology, 17-20 Dec. 2008, pp. 183 – 188.
[23]. Christian Locherta, Martin Mauvea, Holger Füßlerb and Hannes Hartensteinc, “Geographic Routing in City Scenarios,” ACM SIGMOBILE Mobile Computing and Communications Review, Volume 9 Issue 1, Jan. 2005, pp. 69-72.
[24]. U.S. Department of Transportation,"IEEE 1609 - Family of Standards for Wireless Access in Vehicular Environments (WAVE)," April 13, 2013.