Based On Ims Instant Messaging System

So far, the telecommunication services are developing rapidly, the market is changing from the basic call services to the universal information services which be characteristic as value added services. The role of the operators is to be transferred from traditional operators to the universal information services providers. NGN, short for Next Generation Networks, which is charactered as convergence and open and based on IMS, could provide many multimedia services, holding and improving the market for operators. And NGN could provide many kinds of services, such as voice, data, multimedia services and so on. IMS, short for IP Multimedia Subsystem, the core network of the NGN, which can control the core functions for the NGN.The services that IMS provided have been existing in the networks. But these services are developed dependently, different services need different services accessing ,network set up ,service control and the servies application development ,the main network units ,such as charging, even need to own the systems themselves, so the new services is not easily deployed. But IMS provides a strong operational capacity and an ability to integrate all their business by SIP, and unifies the control of the business, which is convenient for our development of instant messaging software.An instant messaging system which can integrate all kinds of multimedia services with SIP in IMS have been analyzed in this thesis.In addition, the system is based on an open source project, the Open IMS Core project. The main contents as following:1 Research the architecture of the IMS, the entities and interfaces of the network, analyze the related protocols, the services architecture, and the mode of the service point trigger for the IMS.2 The service of the instant messaging and presence are introduced in detail, Compared SIMPLE protocol with XMPP protocol, I chose the SIMPLE protocol to build the system, in addition, depict the typical flow of instant messaging in the IMS.3 According to the standard protocol of SIMPLE, I depict the functional mode and demand of IM server and Presence server detailedly in this chapter. 4 Propose how to design and implement the system that user can communicate with each other; Testing the service of sending and receiving messaging, processing the offline message and publishing and subscribing the status of the users.