本論文討論在車用通訊上，802.11e HCCA 的環境下，如何利用有限的頻寬，群播有延遲底限的可調式視訊影片，以最大化接收端影像的品質。首先，在有時間相關性的通道下，分析錯誤率。然後在跨層保護的設計下，考慮延遲底限的影響，提出使用向前錯誤更正的最佳化公式，使用自動重複要求的最佳化公式，以及混和上述兩種保護的混和式最佳化公式，在有限的頻寬內，使頻寬有效的分配在向前錯誤更正以及自動重複要求的保護上，以使接收端所接收到的影片失真最小化。接下來我們模擬在802.11e HCCA的環境下，傳送可調式視訊影片，在不同錯誤率以及不同移動速度下，依照三種最佳化的結果，對可調式視訊影片做不同的保護。最後我們比較在三種最佳化的保護下，接收端的影像品質好壞。而結果顯示，由於混和式最佳化結合了兩種保護措施的優點，所以接收端在影片品質上比另外兩種最佳化更好。

This thesis studies that how to make use of the limited resource to multicast videos which are encoded by the Scalable Video Codec under the 802.11e HCCA vehicle communication environment to maximize the quality of the video received by those receivers. First, the throughput under time-correlated channel is estimated. Then, base on the cross-layer protection design, and take delay bound into account, we propose three optimal formulas using Forward Error Correction(FEC), Auto Repeat Quest (ARQ) and a hybrid method ,respectively. The hybrid method hybrids these two data protection methods to allocate the limited resource to FEC and ARQ protection effectively to minimize distortions of those received videos. After that, we add protections to Scalable video based on the results of these three optimal formulas, and simulate the transmission of protected video under 802.11e environment with different velocity and different error rate. Finally, we compare the quality of those received videos between these three protection optimal formulas, and the result shows that the hybrid optimal formula take advantage of these two protection method, so it performs better then the other two optimal formulas.

[1] Guoping Tan, and Herfet Th., "Optimization of an RTP Level Hybrid Error Correction Scheme for DVB Systems Over Wireless Home Networks Under Restrict Delay Constraint", IEEE Transactions on Broadcasting, Vol. 53, Issue 1, Part 2, pp. 297-307, March 2007.
[2] IEEE Std. 802.11-1999, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, Aug. 1999.
[3] IEEE 802.11a, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, High-speed Physical Layer in the 5 GHz Band, Sep. 1999.
[4] IEEE 802.11e, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: Medium Access Control (MAC) Enhancements for Quality of Service (QoS), Nov. 2005.
[5] “Joint Video Team (JVT) of ISO/IEC MPEG & ITU-T VCEG (ISO/IEC JTC1/SC29/WG11 and ITU-T SG16 Q.6) 15th meeting: Busan, KR, “Joint Scalable Video Model JSVM-2” 16-22 April, 2005.”
[6] jsvm 6.8.1 , Joint Video Team (JVT) of ISO/IEC MPEG & ITU-T VCEG(ISO/IEC JTC1/SC29/WG11 and ITU-T SG16 Q.6) Reference software, April, 2006.
[7] Kihwan Choi and Sunghyun Choi, "CLPC: Cross-layer Product Code for Video Multicast over IEEE 802.11," in Proc. MediaWIN 2006, Athens, Greece, April 2, 2006.
[8] Murray, Todd; Murray, Tammy; Cojocari, Michael; and Huirong Fu, “Measuring the Performance of IEEE 802.11p Using ns-2 Simulator for Vehicular Networks”; IEEE International Conference on Electro/Information Technology, 2008. EIT 2008, Page(s):498 – 503, May 2008
[9] M. Zorzi, R. R. Rao, and L. B. Milstein, “On the accuracy of a fist-order Markov model for data block transmission on the fading channels” , in Proc. IEEE Int. Conf. Universal Personal Communications, Nov. 1995, pp. 211–215.
[10] Qian Zhang, Wenwu Zhu, and Ya-Qin Zhang,”Channel-Adaptive Resource Allocation for Scalable Video Transmission Over 3G Wireless Network”, IEEE Transactions on Circuits and Systems for Video Technology, Volume 14, issue 8, Page(s):1049 - 1063 ,Aug. 2004.
[11] Rashid, M.M.; Hossain, E.; Bhargava, and V.K.;Wireless, “HCCA Scheduler Design for Guaranteed QoS in IEEE 802.11e Based WLANs” , IEEE Communications and Networking Conference, 2007.WCNC 2007, Page(s):1538 – 1543, March 2007
[12] Standard for Wireless Local Area Networks Providing Wireless Communications While in Vehicular Environment, IEEE P802.11p/D2.01, Mar. 2007.
[13] Stephan Eichler, “Performance Evaluation of the IEEE 802.11p WAVE Communication Standard”, In Proceedings of the 1st IEEE International Symposium on Wireless Vehicular Communications (WiVeC) ,Sep 2007
[14] Stibor, L.; Yunpeng Zang; and Reumerman, H.-J, “Evaluation of communication distance of broadcast messages in a vehicular ad-hoc network using IEEE 802.11p”, IEEE Wireless Communications and Networking Conference, 2007.WCNC 2007, Page(s):254 – 257, March 2007
[15] Trsek, Henning; Jasperneite, and Jürgen, “A Simulation Case Study of the new IEEE 802.11e HCCA mechanism in Industrial Wireless Networks “, in: 11th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA 2006) Prague, Sep 2006
[16] Victoria Sgardoni, Pierre Ferré, Angela Doufexi, Andrew Nix, David Bull,”Frame Delay and Loss Analysis for Video Transmission over time -correlated 802.11A/G channels”, The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'07) 3-7Page(s):1 – 5, Sept. 2007.
[17] 馮治軍、張孟俊、李進農,”17.ITS”,工研院電通所視訊與光通訊技術組 (V組) 傳輸技術部, 2003.