Research On The Presence Mechanisms Of IMS Tightly Coupled Conference System

IMS multimedia conference is a typical IMS value-added service, and it is also a hotspot technology of IMS service network. IMS multimedia conference system frameworks can be divided into the centralized conference framework and distributed conference framework. XCON is one of the typical centralized conference frameworks, whose basic features are centralized management and control. It is suitable for applications of business communications and operational services of conferences. So it has become a mainstream technology standard for IMS conference.IMS multimedia conference follows the rules of IP communication technology, and it includes the signal processing and media processing. Kinds of services in a conference are usually implemented by the media session processing, while signal processing is only used for media session management. Currently conference services such as conference voting, conference hands-up etc. within XCON conference are generally implemented through media session. Because of the complexity and difficulty for standardize through media expressing and processing, conference services designed by different manufacturers are incompatible, so the IMS conference application development has been restricted.In fact services in a conference such as voting, hands-up etc. have common characteristics. Their media processing requirements are not complex, and the processing of information interactivity is easy for standardization. At present the conference signaling system has some simple services, such as description of conference resources, and information of the conference members. How to further expand the signaling system of conference Presence, and realize the conference voting and conference hands-up through signal processing is the goal of this thesis. Conference Presence services can inform participants of the various states of the conference and information changes of users in real time in some way while the conference is going. We extend the SIMPLE technology standards to realize conference Presence services, while design the XML documents to describe the state of conference resources, and use SIP extension protocols and conference state documents to realize above functions.On the basis of researching on the SIMPLE protocol standard documents and the framework of XCON conferencing, we complete following tasks. Firstly, we use the SIMPLE framework to subscribe, notify and publish the conference event package in order to realize the conference Presence services. Secondly, we use XML to expand the conference state documents in conference package to support conference voting and conference handsup description. Thirdly, taking into account that the existing conference Presence services only supports one-way notification services, we propose new conference Presence services to add the interactivity of conference Presence services.And we use signal processing to realize conference Presence voting and conference Presence hands-up in this thesis. Finally, we test the entire conference Presence services and additional two conference Presence services. The result shows that the conference state documents and the conference Presence mechanism which are designed in this thesis can realize and extend the conference services in part.