Research And Trial Of The Simulation Platform For Telecom Service Based On IMS

IP Multimedia Sub-system(IMS) is a service control system that is on the basis of IP,it isdistributed, access independence, and open service controle interface.IMS has been recognized to be the core technology of Next Generation Network. It is themost sophisticated and hottest topic now days since it is the key solution for merging currentthree networks, PSTN, mobile network and internet. With the feature of independence indevelopment layer and access layer, ISM significantly reduces the cost and the speed ofdeveloping new services and laying it out. It also provides an easy development environmentfor the third-part business.In this paper, we first have a deep research to the architecture of IMS and it’s applicationtriggering architecture. We also compare it with the traditional services structure. Thearchitecture of IMS masks the complex of the bottom layer of the network. It separates thecontrol of network from the bearer, as well as the service from the control completely, whichprovides an easy development environment for developing new services. In the following part,we analyze the principle of trigger mechanism of IMS based on initial Filtering Criteria (iFC).Especially, the analysis is specific on the function of Service Point Trigger (SPT) in the IMSservice trigger. These work provider a solid foundation for the further simulation of theservice-provide system.We decide to use the open source project, OSIMS, to realize the core network part ofIMS. In this system, we successfully realize the requirement of the element network in3GPPIMS, like CSCF, HSS, BGCF, MGCF, MRF and so on. Furthermore, we choose another opensource project, UCT IMS Client, as the PC client terminal. This project works very well withOSIMS.In the stage of design service, we thoroughly discuss the signalling flow of the process inIMS service trigger.After that, we use UML to model it. Next, vectorization has been appliedto the SIP message. Combine with the theory of FSM, we analyze the whole calling procedure.Then we present a new IMS service development model based on SIP servlet.At last, we use the Sailfin as the application server which is developed by Ericsson. It isthe standard container for SIP Servlet. Also Sailfin can integrate with GlassFish. Someexample services are developed with the Myeclipse toolkit. In these examples, wesuccessfully realize the trigger of service though the configuration of Open IMS Core, inwhich way we could show the function and capable of IMS core network. We also have detailintroduction of these example programs.