低客戶端緩衝空間及小頻寬需求的熱門影片廣播法

Abstract

本文說明TANET 2007研討會之摘要格式，請務必照此格式編排資料廣播技術所需頻寬與請求到達的速率無關, 因此適合用於傳送熱門影片。其中一種廣播技術被稱為定期廣播法 (Periodical Broadcasting), 將熱門影片分割成多個片段 (segment), 然後這些片段同時在不同的資料頻道上重覆播放。一旦使用者想要觀看這個影片, 即從這些頻道下載影片的片段收看。定期廣播法中的 Greedy Disk-conserving Broadcasting (GDB) 允許使用者可以較小頻寬下載影片,與其他類似的方法比較, 如Skyscraper Broadcasting (SkB) 及Client-Centric Approach (CCA), GDB的使用者等待時間較少。本文進一步改善 GDB 讓其使用者所需的緩衝空間 (buffering spaces) 變小, 稱為 Reverse GDB (RGDB), 與 GDB 相比, RGDB 使用者的等待時間及頻寬相同, 在大多數的情況下, RGDB 的緩衝空間需求比 GDB 少35%到50%。

Data broadcasting is independent of arrivals of requests, and thus it is suitable to transmit popular videos that may interest many viewers at a particular period of time. One broadcasting method (called periodic broadcasting) is to divide a popular video into segments, which are then simultaneously broadcast on different data channels. Once clients want to watch the video, they download the segments from these channels. Specially, the greedy disk-conserving broadcasting (GDB) scheme supports a client with a small bandwidth. In comparison with other similar schemes such as the skyscraper broadcasting (SkB) and the client-centric approach (CCA) schemes, the GDB clients have smaller waiting time. Extending GDB, this work designs a reverse GDB (RGDB) scheme to achieve small buffering spaces as well as low bandwidths at the client. Finally, an analysis shows that RGDB has 33%-50% smaller client buffer requirements than GDB in most situations.