Research And Implementation Of Presence Service Based On IMS

IMS (IP Multimedia Subsystem) is introduced by 3GPP (3rd Generation Partnership Project) in its Release 5 version, to support IP multimedia services. IMS is a standard system independent of access technology, and uses SIP (Session Initial Protocol) for session control. By providing standard and open interfaces, IMS separates service and control, and provides end-to-end multimedia services. Presence is an IMS service, which provides functions to allow users to publish their status information, and subscribe others', as well as receive notifications while information changes. As an enabler, Presence is used by other services.The paper makes research of IMS Presence service and development of the service platform. It is divided into six chapters as following.The first chapter describes the background and significance of the paper, the research status, and the related work.The second chapter describes IMS, including concepts, development, and functions. SIP and Diameter are two key protocols in IMS. IMS introduces initial Filter Criteria to support service triggering.The third chapter describes the service system in details, including service model, architecture, protocols, service data and signalings. The core of Presence service is the subscription-notification mechanism based on SIP, and application of XCAP.The fourth chapter introduces two appcalition frameworks, JAIN SLEE and SIP Servlet, focusing on JAIN SLEE. By researching the specification and an open-source implementation, Mobicents, this chapter analyses its architechture, functions, concepts and deployment, and the way of programming based on the framework is also described.The fifth chapter describes in details how to design and implement the Presence service platform based on JAIN SLEE. The first is the system design, and then two key technologies are introduced, followed by the detailed design and implementation of each module, and the last is the deployment and the test of service platform.The sixth chapter makes summary for the work of research and development, and discusses the improvable areas of the implementation, as well as the future work of the paper.