因應無線行動通訊的高度需求，為提升資訊傳輸速率至Gigabits/s (Gbps)以上，已有國際相關標準採用毫米波頻段通訊，例如: 802.11ad、802.11ay、3GPP Release 15等。但毫米波段通訊因具高訊號衰減、低穿透力等特性，促使指向性天線的應用成為必然，而通訊系統即面臨與以往不同的挑戰議題。無人機具有高機動性的特性，使用無人機組成一個無線隨意網絡(ad hoc network)透過單跳或多跳無線鏈路相互通訊和協作可提供可靠通信和即時服務，而利用無人機作為臨時空中基站可增加行動通訊網路的覆蓋率，是未來緊急系統佈局的一種選擇。在無線隨意網路中因缺少中央控制基地台，如何建立有效的傳輸路徑為此相關系統設計的重要考量。本論文依據毫米波通道的特性，探討使用指向性天線之無人機空中基地台的跨實體層/MAC/網路層系統設計，並以模擬驗證所提不同協定設計的系統性能。

To stratify the high demand of wireless mobile communications, several state-of-art international standards, such as IEEE 802.11ad, IEEE 802.11ay, and 3GPP, have chosen millimeter wave (mm-Wave) as a communication band to support the transmission data rate of Gigabits/s (Gbps) or higher. However, due to its high pathloss and low penetration, the mm-Wave communication usually needs to be equipped with directional antenna. As a result, the communication systems will face different challenges from the past. Unmanned aerial vehicles (UAVs) have the characteristics of high flexibility. An ad hoc network formed by UAVs can provide reliable communication and instant services through single-hop or multi-hop wireless links to communicate and cooperate with each other. The UAVs can be used as temporary aerial base stations to extend the coverage of the mobile communication network and this design is a choice for the deployment of the emergency system in the future. The use of UAV-based base stations equipped with directional antennas and operating over the mm-Wave channel has problems with directional antenna systems and limits UAV battery issues. In order to solve this problem, we adopted different MAC layer RTS/CTS access models and QoS routing protocols in the directional antenna system. Simulation results show that the proposed method can enhance the system throughput and achieve better energy efficiency.

[1] R. Roy Choudhury, N.H. Vaidya, “Performance of ad hoc routing using directional antennas,” Journal of Ad Hoc Networks, 2005
[2] V. Kumar, S. Jain and S. Tiwari, “Performance of Routing Protocols in MANETs with Node Density and Mobility using Omni and Directional Antenna” Special Issue of International Journal of Computer Applications on Wireless Communication and Mobile Networks, No.11., pp.51-55, Jan.2012.
[3] Z. Huang, C. Shen, C. Srisathapornphat, and C. Jaikaeo, “A BusyTone Based Directional MAC Protocol for Ad Hoc Networks,” in IEEE Military Communications Conference (Milcom), vol. 2, Anaheim, California, October 2002, pp. 1233–1238.
[4] R. Choudhury and N. Vaidya, “Deafness: A MAC Problem in Ad HocNetworks when Using Directional Antennas,” in IEEE International Conference on Network Protocols (ICNP), Berlin, Germany, October 2004, pp. 283–292.
[5] M. Takata, M. Bandai and T. Watanabe, "A MAC Protocol with Directional Antennas for Deafness Avoidance in Ad Hoc Networks," IEEE GLOBECOM 2007 - IEEE Global Telecommunications Conference, 2007, pp. 620-625, doi: 10.1109/GLOCOM.2007.121.
[6] Gossain, Hrishikesh & Cordeiro, Carlos & Joshi, Tarun & Agrawal, Dharma. (2006). Cross‐layer directional antenna MAC protocol for wireless ad hoc networks. Wireless Communications and Mobile Computing. 6. 171 - 182. 10.1002/wcm.377.
[7] Oubbati,, OS, Mozaffari, M, Chaib, N, Lorenz, P, Atiquzzaman, M, Jamalipour, A. ECaD: Energy-efficient routing in flying Ad hoc networks. Int J Commun Syst. 2019; 32:e4156.
[8] Siuli Roy, Dola Saha, S. Bandyopadhyay, Tetsuro Ueda, and Shinsuke Tanaka. 2003. A network-aware MAC and routing protocol for effective load balancing in ad hoc wireless networks with directional antenna. In Proceedings of the 4th ACM international symposium on Mobile ad hoc networking & computing (MobiHoc '03)
[9] Li, P., Guo, L. & Wang, F. A Multipath Routing Protocol with Load Balancing and Energy Constraining Based on AOMDV in Ad Hoc Network. Mobile Netw Appl (2019).
[10] W. Jiang, Z. Li, C. Zeng and H. Jin, "Load Balancing Routing Algorithm for Ad Hoc Networks," 2009 Fifth International Conference on Mobile Ad-hoc and Sensor Networks, 2009, pp. 334-339, doi: 10.1109/MSN.2009.81.
[11] IEEE802.11ad-2012, “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 3: Enhancements for Very High Throughput in the 60GHz Band,” IEEE Std 802.11ad-2012 (Amendment to IEEE Std 802.11-2012), 2012, pp. 1–628
[12] Bianchi, Giuseppe. “Performance analysis of the IEEE 802.11 distributed coordination function.” IEEE Journal on selected areas in communications 18.3 (2000): 535-547
[13] M. Mozaffari, W. Saad, M. Bennis, Y. -H. Nam and M. Debbah, "A Tutorial on UAVs for Wireless Networks: Applications, Challenges, and Open Problems," in IEEE Communications Surveys & Tutorials, vol. 21, no. 3, pp. 2334-2360, thirdquarter 2019, doi: 10.1109/COMST.2019.2902862.
[14] Robert J. Mailloux, Phased Array Antenna Handbook, Artech Print on Demand Second Edition, 2005
[15] Keysight Technologies Fundamentals of RF and Microwave Noise Figure Measurements, Keysight Technologies
[16] IEEE: IEEE 802.11. IEEE Standards for Information Technology.
[17] C.E. Perkins, E.M. Belding-Royer, S.R. Das, Ad hoc on-demand distance vector (AODV) routing, IETF RFC3561, July 2003.
[18] Bazan, O. and M. Jaseemuddin. “An Opportunistic Directional MAC Protocol for Multihop Wireless Networks with Switched Beam Directional Antennas.” 2008 IEEE International Conference on Communications (2008): 2775-2779.
[19] Jain, R K., Chin, D.-M W., & Hawe, W. R. (1984). A Quantitative measure of fairness and discrimination for resource allocation in Shared Computer Systems,” DEC-TR-301