Enhancing the Presence Service Efficiency of Internet Protocol Multimedia Subsystem-Based Web Services

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 multimedia services. However, current IMS users have been developed separately based on various operating systems or devices. This study adopted a web-based IMS user and deployed a gateway between IMS users and an IMS network. Users can access IMS services by employing any device equipped with a web browser which supports a web real-time communication application programming interface. Since more real-time messaging services have exploited presence services (PSs) to issue user status information, a high number of status messages are generated. Instead of using the extensible markup language (XML) format to exchange presence data in PSs, this study adopted JavaScript object notation (JSON), which has a more compact and lightweight format for reducing the message volume and delay. This study evaluated the system performance based on XML and JSON data formats under realistic conditions. The results show that adopting JSON can effectively reduce the message volume and delay by approximately 40 and 54 %, respectively.