Research And Implementation Of Voip Value-added Services Based On SIP Protocol In IMS

Network Convergence is an important characteristic of NGN. Thanks to the highlydevelopment of global information industry, it is the inevitable trend for future. The corenetwork of NGN will complete the evolution step by step from Soft Switch to IMS.IMS is the sub-system in the R5version standard presented by3GPP, which cansupport the IP multi-media services. IMS utilized SIP protocol which is flexible and easilyexpanded to setup, modify and end all kinds of multi-media services. The proposed newconcept of Triple-play which brings a variety display forms of the value-added services.As technology advances, the requirements of VoIP value-added services present thecharacteristics of intelligentization, multi media-oriented, individuation and diversification.Firstly, this paper elaborates on the development trend of Network Convergence inmodern communication network. Secondly, the network architecture of IMS, the structureof SIP protocol which for creating a session, and the message form and format of SDPprotocol which for describing a session are analyzed. Then, the requirement analysis ofVoIP value-added services are discussed. The design proposal of the VoIP value-addedservices is provided by means of researching the SIP signalling message based on thethought of functional module division. And the detailed design of SIP Call ProcessorModule which completes the function of VoIP basic and value-added services is proposed.In the subsequent step, the state machine of VoIP value-added services based on SIP isdesigned. Furthermore, three kinds of typical VoIP value-added services includingThree-way Conference, Blinded Call Transfer and Attended Call Transfer services areimplemented in ONU of IMS terminal devices. Afterwards, these services are tested whilethe result shows that its availability is checked in IMS. Finally, the dissertation arrives atthe summarizing stage and some expectations for the next research are put forward.