在過去十年間，因為智慧型手機及行動裝置的普及，在行動網路中使用VoIP以及多媒體服務已成為主要的趨勢，IP多媒體子系統(IMS)為次世代網路(NGN)其中一個解決方案，此平台能基於IP技術提供多樣性的多媒體服務，然而目前IMS的客戶端軟體都是針對不同的作業系統(OS)分別開發，基於服務導向的Web服務能有效地解決此問題，這篇研究中，我們在IMS網路與IMS客戶端之間佈署了一閘道，使用者將能透過支援WebRTC的網頁瀏覽器使用IMS的服務。由於使用狀態服務(PS)來取得與發佈使用者的狀態的服務日益增多，導致大量的訊息在網路中產生，我們在這篇研究中採用了JSON取代XML來交換使用者的狀態資訊，JSON是一種輕量化的資料交換語言，能有效的減少訊息量與延遲時間。研究中，我們在實際的環境中評估了基於XML與JSON的系統，評估結果顯示採用JSON的系統能有效的減少約40%的訊息量與54%的延遲時間，此篇研究也將基於IMS系統的Web服務應用在小規模的教學環境中，能保證使用者在各種不同裝置上都能透過IMS上的視訊通話或視訊會議有效的溝通。

Over the past decade, voice-over-Internet protocol technologies and multimedia services for mobile devices have become a major trend of mobile networks because of the pervasiveness of handheld devices and the increased availability of advanced cellular networks worldwide. Next-generation network solutions, such as Internet protocol multimedia subsystems (IMS), offer considerable potential for providing various IP multimedia service. However, current IMS clients have been developed separately based on various operating systems. Service-oriented architectures based on web services can effectively overcome the problem. This study adopted a web-based IMS client and deployed a gateway between IMS clients and an IMS network. Users can access IMS services by employing any device equipped with a web browser supporting a web real-time communication application programming interface. Because more services have increasingly exploited presence services (PSs) to retrieve and republish user information, a high number of message are generated. Instead of using the extensible markup language (XML) format to exchange presence messages in PSs, this study adopted JavaScript object notation (JSON), which is a more compact and lightweight format for reducing the message value and delay. This study evaluated a system based on XML and JSON data formats under realistic conditions. The results show that adopting JSON can effectively reduce the message value and delay by approximately 40% and 54%, respectively. This study also applied a small-scale IMS-based environment for an educational computer system. Leveraging IMS and web services featuring video and conference calls on IMS ensures that they perform more efficiently in heterogeneous devices and network environments.

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