在現今的文獻中，有許多根基於廣播(broadcasting-based)的方法來提供近乎隨選視訊(Video-On-Demand)的服務。然而，這些方法並不支援無隙縫式動態調整頻寬(seamless channel transition)的特性。單純的為了transition再多配置新的頻寬將會導致伺服器負擔增加，浪費網路頻寬，甚至把可用的頻道耗盡。
我們已經成功的把Fast Broadcast scheme(FB scheme)加上了此一特性，而我們也繼續嘗試著將其他broadcasting based schemes加上此一特性。在這篇論文中，我們闡述了如何為Staircase Broadcast scheme(SB scheme)加上seamless channel transition的特性。主要動機是因為SB scheme所需的buffering space較FB scheme小，但又能維持跟FB一樣長的user waiting time。我們會在第四章對其效能與優點有詳細的說明。

In the literature, many broadcasting-based schemes have been
proposed to efficiently support near-VOD services. However, none
of these schemes can support dynamic and seamless channel
transition, which is sometimes essential for a server to change
the number of channels allocated to a video. Naively allocating a new set of channels for the transition could increase server''s
load, waste communication bandwidth, and even drain the channels
of the system.
We have shown how to enhance the FB scheme for seamless channel transition. The problem remains open whether other broadcasting-based schemes can sustain seamless channel transition. In this paper, we show how to enhance the SB scheme to seamlessly
increase or decrease the channels allocated to a video. The
motive to do so is that SB has been proved to required
significantly less buffering space than FB, while sustaining the
same startup latency as FB. Detailed performance comparisons are
presented to demonstrate the advantages of the proposed scheme.

[1] C. C. Aggarwal, J. L. Wolf, and P. S. Yu, “A permutation-based pyramid broadcasting scheme for video-on-demand systems,” in IEEE Proceedings of the International Conference on Multi-media
Computing and Systems, June 1996, pp. 118—126.
[2] T. Chiueh and C. Lu, “A periodic broadcasting approach to video-on-demand service,” SPIE, vol. 2615, pp. 162—169, Oct. 1995.
[3] A. Dan, D. Sitaram, and P. Shahabuddin, “Scheduling policies for an on-demand video server with batching,” in Proc. of ACM Multimedia, 1994, pp. 15—23.
[4] A. Dan, D. Sitaram, and P. Shahabuddin, “Dynamic batching policies for an on-demand video server,” Multimedia Systems, vol. 4, no. 3, pp. 112—121, June 1996.
[5] L. Gao, J. Kurose, and D. Towsley, “Efficient schemes for broadcasting popolar videos,” in International Workshop on Network and Operaing Systems Support for Digital Audio and Video, Aug. 1998, pp. 317—329.
[6] K. A. Hua and S. Sheu, “Skyscraper broadcasting: a new broadcasting scheme for metropolitan video-on-demand systems,” in ACM SIGCOMM, Sept. 1997.
[7] L.-S. Juhn and L.-M. Tseng, “Fast broadcasting for hot video access,” in RTCSA’97, Oct. 1997, pp. 237—243.
[8] L.-S. Juhn and L.-M. Tseng, “Harmonic broadcasting for video-on-demand service,” IEEE Transactions on Broadcasting, vol. 43, no. 3, pp. 268—271, Sept. 1997.
[9] L.-S. Juhn and L.-M. Tseng, “Enhanced harmonic data broadcasting and receiving scheme for
popular video service,” IEEE Transactions on Consumer Electronics, vol. 44, no. 2, pp. 343—
346, May. 1998.
[10] L.-S. Juhn and L.-M. Tseng, “Fast data broadcasting and receiving scheme for popular video service,” IEEE Transactions on Broadcasting, vol. 44, no. 1, pp. 100—105, Mar. 1998.
[11] J.-F. Paris, “A simple low-bandwidth broadcasting protocol,” in International Conference on Computer Communication and Network, 1999, pp. 118—123.
[12] J.-F. Paris, S.-W. Carter, and D.-D.E. Long, “A hybrid broadcasting protocol for video on demand,” in Multimedia Computing and Networking, 1999, pp. 317—326.
[13] S. Viswanathan and T. Imielinski, “Metropolitan area video-on-demand service using pyramid broadcasting,” Multimedia Systems, vol. 4, pp. 197—208, 1996.
[14] Y. C. Tseng, C. M. Hsieh, M. H. Yang, W. H. Liao, and J. P. Sheu., “Data broadcasting and seamless channel transition for highly-demanded videos,” IEEE INFOCOM 2000, pp. 727—
736, 2000.
[15] L.-S. Juhn and L.-M. Tseng, “Staircase data broadcasting and receiving scheme for hot video service,” IEEE Transactions on Consumer Electronics, vol. 43, no. 4, pp. 1110—1117, Nov.1997.
[16] Y. H. Chang, D. Coggins, D. Pitt, and D. Skellern, “An open system approach to video on demand,” IEEE Communication Magazine, vol. 32, pp. 68—80, May. 1994.
[17] W. D. Sincoskie, “System architecture for a large scale video on demand service,” Computer Networks and ISDN systems, vol. 22, pp. 565—570, 1991.
[18] D. Deloddere, W. Verbiest, and H. Verhille, “Interactive video on demand,” IEEE Communications Magazine, vol. 32, pp. 82—88, May. 1994.
[19] T. D. C. Little and D. Venkatesh, “prospects for interactive video-on-demand,” IEEE Multimedia, vol. 1, no. 3, pp. 14—24, Mar. 1994.
[20] L. Atzori, F.G.B. De Natale, M. Di Gregorio, and D. D. Giusto, “Multimedia information broadcasting using digital TV channels,” IEEE Transactions on Broadcasting, vol. 43, no. 3,
pp. 242—251, Sept. 1997.
[21] M. Cominetti, V. Mignone, A. Morello, and M. Visintin, “The european system for digital multi-programme television by satellite,” IEEE Transactions on Broadcasting, vol. 41, no. 2,
pp. 49—62, June 1995.
[22] C. C. Aggarwal, J. L. Wolf, and P. S. Yu, “On optimal batching policies for video-on-demand storage servers,” in IEEE Proceedings of the International Conference on Multimedia Computing and Systems, June 1996, pp. 253—258.
[23] L. Gao and D. Towsley, “Supplying instantaneous video-on-demand services using controlled multicast,” in IEEE Multimedia, 1999, pp. 117—121.
[24] K.A. Hua, Y. Cai, and S. Sheu, “Patching: A multicast technique for true video-on-demand services,” in ACM Multimedia, Sept. 1998, pp. 191—200.
[25] Z.-Y. Yang, L.-S. Juhn, and L.-M. Tseng, “On optimal broadcasting scheme for popular video service,” IEEE Transaction on Broadcasting, vol. 45, no. 3, pp. 318—322, 1999.