The Design And Realization Of The IMS User Agency In Access Gateway Control Function

During the past years, telecom industry, which has developed at full speed, is undergoing more and more impact. The incoming of the whole operation remains increase, but the speed has already descended obviously, and the profit margin has decreased continuously. With the development of VolP, mobile communication, internet technology, and the voice operations from fixed network carriers being impacted supremely especially, carriers are looking for a new mode or scheme to re-combine the existing operations. At the same time, the concepts of NGN (next generation network) and FMC (fixed and mobile convergence) are proposed, which provide a viable solution for them. At present, all the big communication suppliers have proposed viable solutions for FMC, among which, for fixed network, IMS-based PES in TISPAN NGN has become an important part to evolving towards NGN.Firstly, from the angle of the whole network, this paper introduces the basal concept of NGN, the evolvement of NGN standardization and the concept of FMC. The concept and the network configuration of TISPAN NGN, including NASS, RACS, PES, IMS, are introduced emphatically. Then, the concept and standardization, the network configuration of TISPAN IMS are described detailedly, so does the IMS-based PES.After that, for the work flow of inside network element in AGCF and SIP signal communication flow can be described more clearly, the paper introduces several protocols, including SIP, H. 248 and SDP, which are related to AGCF.In the latter part of the paper, combining the actual development, the author has researched detailedly the network configuration and the inside function module of AGCF entity which is the pivotal function entity in PES, and analysed the design of AGCF function entity by network configuration and software logical configuration. This paper analyses emphatically the design and realization of IMS-UA, including SIP stack modification, the design of SIPUAM, the design and realization of SIPUA basic functions and so on. And combining the actual SIP signal communication flow, the register/deregister, subscribe/notify event and call/session control functions are designed and realized.At last, the author summarizes the previous work, introduces next development scheme, expects the application foreground of AGCF in FMC and proposes advice for the future design and development.