In wireless network, video transmission has been used widely in some applications such as
video phone, Internet Protocol TV (IPTV), etc. An important issue of supporting multi-user
video streaming over wireless networks is how to optimize the video quality. Generally, the
receiver uses the error concealment techniques to recover the visual quality when some video
packets are lost. In the sense of minimum mean square error (MSE), this work analyzed the
allowable repeats of ARQ, which is an oft-used error control approach, and proposed that
the transmission e±ciency can be improved if the communications system can concurrently
take integrated consideration of ARQ and error concealment. Furthermore, we add a channel
selected scheme to increase ARQ performance. Since these approaches will bene‾t from each
other, this work will demonstrate that the visual quality can be accordingly improved about
0.223 dB of Peak Signal-to-Noise Ratio (PSNR) value in the simulation results.

在無線網路環境中，影像傳輸已被廣泛的應用，如視訊電話，網路電視（IPTV）…等。而在此環境中，要如何同時傳輸影像資料、服務多個使用者，而維持其影像品質最佳，是一項重要的課題。一般來說，接收器使用錯誤隱藏(Error concealment) 技術，可以彌補一些影像傳輸時，封包漏失所造成的品質低落問題。基於此理念，我們使用了最小均方誤差（Mean Square Error），分析了影像失真度。此外，我們的研究分析了在納入允許重複的自動重傳請求技術(Automatic Repeat-reQuest ARQ )這個經常使用的錯誤控制方法下的效能為何。並假設如果可以同時採取綜合使用自動重傳請求和錯誤隱藏的情形下，可以提高通信系統的影像傳輸品質。另外，我們提出了一種新的錯誤隱藏策略，可以做為實行錯誤隱藏時的一個使用選項。最後，我們添加一個頻道選定(channel selection)的機制。從網路環境中多個頻道中選出最佳者，以提升自動重傳請求的效能。由於自動重傳請求與錯誤隱藏方法所得到的結果可以彼此互惠。因此我們的實驗結果顯示，影像傳輸品質可以相應提高約0.223分貝的峰值雜訊比(Peak Signal-to-Noise Ratio PSNR)。

1 Introduction ..............................1
2 transmission improving Scheme .............4
2.1 maximum ARQ times .......................4
2.2 channel selection .......................7
3 concealment improving scheme .............10
3.1 proposed error concealment method ......10
3.2 Error concealment with ARQ scheme ......12
4 performance evaluation ...................16
5 conclusion ...............................19

[1] Y. Xu and Y. Zhou, \H. 264 video communication based re‾ned error concealment
schemes," IEEE Trans. on Consumer Electronics, vol. 50, no. 4, pp. 1135{1141, 2004.
[2] V. C. Santosh and J. R. Je□rey, \Low complexity error concealment scheme for intra-
frames in h.264/avc," in IEEE International Conference on Image Processing ICIP,
2009.
[3] Y. K. Wang, M. M. Hannuksela, V. Varsa, A. Hourunranta, and M. Gabbouj, \The
error concealment feature in the h. 26l test model," in Proc. ICIP, vol. 2. Citeseer,
2002, pp. 729{732.
[4] M. S. Bazaraa, J. J. Jarvis, and H. D. Sherali, Linear programming and network °ows.
Wiley, 2009.
[5] L. P. Kondi, D. Srinivasan, D. A. Pados, and S. N. Batalama, \Layered video transmis-
sion over wireless multirate ds-cdma links," IEEE Transactions on Circuits and Systems
for Video Technology, vol. 15, no. 12, pp. 1629{1637, 2005.
[6] S. Sanayei and A. Nosratinia, \Antenna selection in mimo systems," IEEE Communi-
cations Magazine, vol. 42, no. 10, pp. 68{73, 2004.
[7] L. Zhou, X. Wang, W. Tu, G. Mutean, and B. Geller, \Distributed Scheduling Scheme
for Video Streaming over Multi-Channel Multi-Radio Multi-Hop Wireless Networks,"
IEEE Journal on Selected Areas in Communications, vol. 28, no. 3, pp. 409{419, 2010.
[8] J. Luo., K. R. Pattipati, P. Willett, and G. M. Levchuk, \Fast optimal and suboptimal
any-time algorithms for cdma multiuser detection based on branch and bound," IEEE
Transactions on Communications, vol. 52, no. 4, pp. 632{642, 2004.
[9] S. Kumar, L. Xu, M. K. Mandal, and S. Panchanathan, \Error resiliency schemes in
h. 264/avc standard," Journal of Visual Communication and Image Representation,
vol. 17, no. 2, pp. 425{450, 2006.
[10] T. Wiegand, G. J. Sullivan, G. Bjontegaard, and A. Luthra, \Overview of the h. 264/avc
video coding standard," IEEE Transactions on circuits and systems for video technology,
vol. 13, no. 7, pp. 560{576, 2003.
[11] X. Hei, C. Liang, J. Liang, Y. Liu, and K. W. Ross, \A measurement study of a large-
scale p2p iptv system," IEEE Transactions on Multimedia, vol. 9, no. 8, p. 1672, 2007.
[12] M. Wu, S. Makharia, H. Liu, D. Li, and S. Mathur, \Iptv multicast over wireless lan us-
ing merged hybrid arq with staggered adaptive fec," IEEE transactions on broadcasting,
vol. 55, no. 2, p. 363, 2009.
[13] M. K. Jubran, M. Bansal, L. P. Kondi, and R. Grover, \Accurate distortion estimation
and optimal bandwidth allocation for scalable h. 264 video transmission over mimo
systems," IEEE Transactions on Image Processing, vol. 18, no. 1, pp. 106{116, 2009.
[14] K. Song, T. Chung, Y. Oh, and C. S. Kim, \Error concealment of multi-view video se-
quences using inter-view and intra-view correlations," Journal of Visual Communication
and Image Representation, vol. 20, no. 4, pp. 281{292, 2009.
[15] S. Winkler, Digital video quality: vision models and metrics. Wiley, 2005.
[16] T. Wiegand, G. J. Sullivan, G. Bjontegaard, and A. Luthra, \Overview of the h. 264/avc
video coding standard," IEEE Transactions on circuits and systems for video technology,
vol. 13, no. 7, pp. 560{576, 2003.
[17] A. Steiner and S. Shamai, \Multi-layer broadcasting hybrid-arq strategies for block
fading channels," IEEE Trans. Wireless Commun, vol. 7, no. 7, pp. 2640{2650, 2008.