隨著網路速度提升與普及因此有許多服務讓我們解決跨地區的問題，不再需要親臨現場或是觀看電視直播才能參與或收看整個活動，而能透過網路來直接觀看現場的情形甚至與遠端的人互動，但是對於重要的會議時，能夠提供一個穩定且可靠的方法來讓遠端參與者與現場互動則是一個重要的議題，並且如何能讓線上會議在有效率的方式下於網路上進行也是值得我們去思考與解決的方向。
為了提供線上會議更穩定的服務，我們使用了較於可靠與穩定的PSTN來讓參與者間進行語音通話，並由我們的雲端橋接電話機系統( Cloud Bridging Switch, CBS)來串接多方通話，讓參與者能與主持人間對話之外，還能再將其他語音廣播至遠距會議室，讓其他來賓也能聆聽會議間的對話，並且我們提供了Q&A的服務平台，使與會者可以提出想問的問題給主持人進行問答，並讓主持人可以針對會議的問題做統一的管理；我們的Q&A平台可以與現行之線上會議系統( Web Conferencing) 或線上轉播平台( Webcast) 搭配使用，提供主辦單位使用原先的會議系統傳送視訊內容，使用本平台做統一的Q&A管理，並且取代傳統透過網路電話傳遞語音的方式，改由透過撥打PSTN電話至提問者之手機，進而改善品質與提升可靠度，也可以支援透過手機參與整個線上會議討論的功能，而不再需要依靠桌上型電腦或是會議視訊設備等裝置，讓線上會議可以更方便快速的在各種地點進行。

Due to the network speed is growing rapid and more popular, there are many services provided to solve the cross-region problems. If we want to participate the activities, we don’t need to go to the real place where the activity is located or even watch the Live TV. However, we can directly use Internet to join the activities, even interacting with remote people is not a problem. Additionally, when participating in important seminar, supporting a stable and reliable way for remote audience to interact with host is an important issue. Moreover, providing the efficient method for online seminar to process is also a challenge. What’s important, these indicated scenarios are addressed appropriately in this paper.
For the purpose of providing online seminar a better service, we use PSTN, which is more reliable and stable, for audience to communicate with each other. Besides, our Cloud Bridging Switch (CBS) can bridge calls as a conference call; thus, the audience not only can talk with host but also can broadcast theirs conversation to the other audience. Moreover, we offer a Q&A service platform that audience can raise their questions for host to answer, and the questions are collected as a unified list for host to manage. Our system is able to collaborate with other webcast, web conferencing or online broadcasting platforms, the host could use broadcasting platform to broadcast video streaming, and use our system to process Q&A management by replacing the traditional way for sending voice such as VoIP phone. Our solution, which calls to question raiser via PSTN not only improves the stability but also supports online seminar’s discussion attending through mobile.

Chapter 1 Introduction 1
Chapter 2 Related Works 4
2.1 Webcast 4
2.2 Web Conferencing 5
2.3 Comparison 7
Chapter 3 System Design and Implementation 10
3.1 System Overview 11
3.1.1 Web Service Server 12
3.1.2 Cloud Bridge Switch 13
3.1.3 Database Server 14
3.1.4 Flow of Client Request 16
3.2 System Implementation 17
3.2.1 Tools for Developing the Web Service 17
3.2.2 The Web Services 21
Chapter 4 Experiment Results 33
4.1 Influence Caused by Delay on Webcast Platform 35
4.2 Influence Caused by Delay on Web Conferencing Platform 37
4.3 Echo Reduction 38
4.4 Recommended Arrangement 44
4.3.1 Casting Room 44
4.3.2 Remote Group Room 46
4.3.3 Remote Personal Users 47
Chapter 5 Conclusion and Future Works 50
References 52

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