車輛即連網絡(vehicle ad hoc network, VANET) 可以幫助實現多樣的智慧運輸系統(Intelligent Transportation Systems, ITS)的相關應用。例如，可及時散播安全信息來提高行車安全性；收集道路交通信息以緩解城市中交通擁堵，網絡連接在車輛即連網絡中應用程序的服務品質(Quality of servers, QoS)。
本文探討在稀疏快道上的一個車輛即連網絡(vehicle ad hoc network, VANET)中，一部車輛傳遞訊息到它的後方車輛端到端延遲(end-to-end delay)的分析與討論，並討論雙向車流密度不同的情況，之前已經有很多討論修復延遲的論文。然而，大多數其中忽略了網絡斷開恢復對前一次斷開的依賴性。為了解決這個問題，我們討論恢復網絡斷開可能會受到前一個斷開的影響，從而開發出嵌入式馬可夫鏈EMC (Embedded Markov Chain)得到恢復延遲的穩態概率分佈。模擬的結果顯示，我們的分析是高度準確的。

Vehicle ad hoc network (VANET) can help realize various applications related to Intelligent Transportation Systems (ITS). For example, safety information can be disseminated in a timely manner to improve driving safety; road traffic information can be collected to alleviate traffic congestion in cities, and the Quality of Servers (QoS) of network connection applications in vehicles is connected to the network.
This paper discusses the analysis and discussion of the end-to-end delay of a vehicle transmitting a message to its rear vehicle in a vehicle ad hoc network (VANET) on a sparse highway, and discussing the case where the two-way traffic density is different, there have been many papers discussing repair delays before. However, most of them ignore the dependence of network disconnection recovery on the previous disconnection. In order to solve this problem, we discuss that the recovery network disconnection may be affected by the previous disconnection, and thus develop the EMC (Embedded Markov Chain) to obtain the steady-state probability distribution of the recovery delay. The simulation results show that our analysis is highly accurate.

[1] C. De Francesco, C. E. Palazzi, and D. Ronzani, “Fast message broadcasting in vehicular networks: Model analysis and performance evaluation,” IEEE Commun. Lett., vol. 24, no. 8, pp. 1669–1672, 2020.

[2] “IEEE draft standard for local and metropolitan area networks - station and media access control connectivity discovery amendment: YANG data model,” IEEE P802. 1ABcu/D2. 1, July 2021, pp. 1–51, 2021.

[3] A. M. I. Mahbub and A. A. Malikopoulos, “A platoon formation framework in a mixed traffic environment,” IEEE Control Syst. Lett., vol. 6, pp. 1370–1375, 2022.

[4] D. Yang, P. Du, M. Zhong, and W. Mao, “A real-time fusion method of external trajectory measurement data based on variable difference method,” in 2020 IEEE 9th Joint International Information Technology and Artificial Intelligence Conference (ITAIC), 2020, vol. 9, pp. 574–577.

[5] C. Lienke, C. Wissing, M. Keller, T. Nattermann and T. Bertram, "Predictive Driving: Fusing Prediction and Planning for Automated Highway Driving," in IEEE Transactions on Intelligent Vehicles, vol. 4, no. 3, pp. 456-467, Sept. 2019.

[6] Z. Shen, X. Zhang, and D. Yang, “Performance analysis of extended sensor sharing in vehicular ad hoc networks,” in 2018 International Symposium on Antennas and Propagation (ISAP), 2018, pp. 1–2.

[7] M. N. Tahir, M. Katz, and Z. Javed, “Poster: Connected vehicles using short-range (WI-fi & IEEE 802.11p) and long-range cellular networks (LTE & 5G),” in 2021 IEEE 29th International Conference on Network Protocols (ICNP), 2021, pp. 1–2.

[8] D. Schitz, D. Rieth, and H. Aschemann, “Corridor-based motion planning for teleoperated driving tasks,” in 2021 IEEE International Intelligent Transportation Systems Conference (ITSC), 2021, pp. 673–680.

[9] R. Kumar, A. Saad, and R. E. De Grande, “COrRect: Connection-oriented resource matching for vehicular clouds,” in ICC 2021 - IEEE International Conference on Communications, 2021, pp. 1–6.

[10] F. Ayaz, Z. Sheng, D. Tian, and Y. L. Guan, “A proof-of-quality-factor (PoQF)-based blockchain and edge computing for vehicular message dissemination,” IEEE Internet Things J., vol. 8, no. 4, pp. 2468–2482, 2021.

[11] P. Kohli, S. Sharma, and P. Matta, “Security of cloud-based vehicular ad-hoc communication networks, challenges and solutions,” in 2021 Sixth International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET), 2021, pp. 283–287.

[12] M. Kafsi, Panagiotis Papadimitratos, Olivier Dousse, Tansu Alpcan, Jean-Pierre Hubaux: VANET Connectivity Analysis. CoRR abs/0912.5527 (2009) text to speech.

[13] M. Kamya, J. Mwebaze, and M. Okopa, “Modeling connectivity for vehicular adhoc networks under interference,” in 2021 Fifth World Conference on Smart Trends in Systems Security and Sustainability (WorldS4), 2021, pp. 87–95.

[14] S. M. Abuelenin and S. Elaraby, “A generalized framework for connectivity analysis in vehicle-to-vehicle communications,” IEEE Trans. Intell. Transp. Syst., vol. 23, no. 6, pp. 5894–5898, 2022.

[15] A. R. Deshmukh, P. Nirmal, and S. S. Dorle, “A new approach for position based routing protocols based on ant colony optimization (ACO) technique in vehicular ad hoc network (VANET),” in 2021 International Conference on Intelligent Technologies (CONIT), 2021, pp. 1–5.

[16] K. Aravindhan, K. Periyakaruppan, K. Balaji, S. Banupriya, S. R. Sankari, and A. Vignesh, “Experimental design of VANET routing using enhanced ant colony optimization technique,” in 2021 7th International Conference on Advanced Computing and Communication Systems (ICACCS), 2021, vol. 1, pp. 1515–1518.

[17] X. Wang, Y. Weng, and H. Gao, “A low-latency and energy-efficient multimetric routing protocol based on network connectivity in VANET communication,” IEEE Trans. On Green Commun. Netw., vol. 5, no. 4, pp. 1761–1776, 2021.

[18] M. Wadea, A. Mostafa, D. P. Agrawal, and A. Hamad, “Enhancing VANET connectivity through utilizing autonomous vehicles,” in 2017 IEEE 13th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob), 2017, pp. 204–211.

[19] G. A. Ahmed, T. R. Sheltami, A. S. Mahmoud, M. Imran, and M. Shoaib, “A novel collaborative IoD-assisted VANET approach for coverage area maximization,” IEEE Access, vol. 9, pp. 61211–61223, 2021.

[20] S. Jiang, T. Chang, A. Jia, and W. Wang, “A study on vehicle connectivity and its impact on positioning,” in 2021 15th European Conference on Antennas and Propagation (EuCAP), 2021, pp. 1–5.

[21] A. Aboud, H. Touati, and B. Hnich, “Markov Chain based Predictive Model for Efficient handover Management in Vehicle-to-Infrastructure Communications,” in 2021 International Wireless Communications and Mobile Computing (IWCMC), 2021, pp. 1117–1122.

[22] S. Yousefi, E. Altman, R. El-Azouzi, and M. Fathy, “Analytical model for connectivity in vehicular ad hoc networks,” IEEE Trans. Veh. Technol., vol. 57, no. 6, pp. 3341–3356, 2008.

[23] S.-I. Sou, W.-C. Shieh, and Y. Lee, “A video frame exchange protocol with selfishness detection mechanism under sparse infrastructure-based deployment in VANET,” in 2011 IEEE 7th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob), 2011, pp. 498–504.

[24] J.-J. Huang and Y.-T. Tseng, “The steady-state distribution of rehealing delay in an intermittently connected highway VANET,” IEEE Trans. Veh. Technol., vol. 67, no. 10, pp. 10010–10021, 2018.

[25] C. Huang, M. Chiang, W. Su and D. Dao, "SDN-based V2V offloading for cellular network using the LifeTime-based network state routing (LT-NSR)," 2018 International Conference on Information Networking (ICOIN), 2018, pp. 274-279.

[26] C. -M. Huang and C. -F. Lai, "The Delay-Constrained and Network-Situation-Aware V2V2I VANET Data Offloading Based on the Multi-Access Edge Computing (MEC) Architecture," in IEEE Open Journal of Vehicular Technology, vol. 1, pp. 331-347, 2020.

[27] J.-J. Huang, J.-H. Lu, and J.-Y. You, “A delay analysis for the delivery of downstream safety related messages in vehicle ad hoc networks,” in 2021 IEEE International Symposium on Product Compliance Engineering - Asia (ISPCE-ASIA), 2021, pp. 01–05.

[28] Y. Wang, J. Zheng and N. Mitton, "Delivery Delay Analysis for Roadside Unit Deployment in Vehicular Ad Hoc Networks With Intermittent Connectivity," in IEEE Transactions on Vehicular Technology, vol. 65, no. 10, pp. 8591-8602, Oct. 2016.

[29] L. Zhu, C. Li, B. Li, X. Wang and G. Mao, "Geographic Routing in Multilevel Scenarios of Vehicular Ad Hoc Networks," in IEEE Transactions on Vehicular Technology, vol. 65, no. 9, pp. 7740-7753, Sept. 2016.

[30] Y. Zhuang, J. Pan, Y. Luo and L. Cai, "Time and Location-Critical Emergency Message Dissemination for Vehicular Ad-Hoc Networks," in IEEE Journal on Selected Areas in Communications, vol. 29, no. 1, pp. 187-196, January 2011.

[31] J. Huang, "Accurate Probability Distribution of Rehealing Delay in Sparse VANETs," in IEEE Communications Letters, vol. 19, no. 7, pp. 1193-1196, July 2015.