視訊會議在區域網路上之發展與效能評估

Abstract

視訊會議允許一群在不同地方的使用者，利用電腦及一些相關的設備，如 攝影機及影像卡、喇叭與聲霸卡，網路等，達成及時開會的目的；開會者 必須能透過網路，同時看到並可編輯相關的多媒體資料，包括文字、圖畫 、影像、聲音以及手寫的資料。視訊會議系統的概念，在很多年前即已提 出，也有很多人從事此方面的研究發展，但是這些系統大部分都利用專線 來傳送，所需的成本相當高，如果可以利用區域網路來傳送，將可以加速 此類系統的普及化。近來，由於高速網路的出現，在區域網路上己經可以 發展視訊會議系統，本論文的目的即是利用市面上的產品，發展一個簡單 的視訊會議系統，並找出影響其效能的因素。在另一方面，我們將利用此 發展經驗來分析區域網路支援視訊會議系統可能產生的問題，並提出解決 的方法。 Video conference systems allow the people at different office locations to communicate with each other through video, voice, and static data such as text, graphics or images. The idea of video conference systems has been studied for many years. There are many literature in this field. So far, most existing video conference systems use dedicated lines to carry traffic. However, to set up dedicated lines is expensive in general. If video conference systems can be developed on local area networks(LANs), the coverage area can be extended to the users without using dedicated system. This approach will make video conference systems more popular. With the increasing power of modern computers and high speed network technologies, it is possible to develop video conference systems on LANs. In this thesis, we try to built a prototype of video conference system with inexpensive products and explore the factors affecting its performance. On the other hand, we will analyze the problems of video conference system over LAN and propose the methods to solve them.