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.
