The Study And Implementation Of Home Subscriber Server In IP Multimedia Subsystem

IMS (IP Multimedia Subsystem) is driven by 3GPP (The 3rd Generation Partnership Project) as the 3G core network infrastructure. IMS is designed to fill the gap between the existing traditional telecommunication technology and Internet technology over an all IP based network. This will allow operators to offer new, innovative services that shareholders and end users are expecting. After the Releas 5 of 3GPP specification, there is a data centralized entity named by HSS in the IMS architecture, which stores all the user service information of the whole network. HSS is one of the most important function entities in IMS system. Owing to centralized data in HSS, it is much available for IMS to achieve the convergence of different kinds of access network, such as mobile access network and fixed access network. The objective of the paper is to research the latest HSS related specifications and to provide a solution to facilitate the design and realization of HSS function entity.This paper, after introducing the technology background and research status of IMS and HSS, analyses the characteristic and function requirement of HSS based on the specification. Then, it mainly focuses on the design and implement of the HSS, especially on the design idea and innovation points. Based on the test result, this paper deduces a conclusion that the system is available in practice.This paper is separated into seven chapters. The chapter one introduces the research background and main work accomplished during the paper writing process. In the chapter two, a comprehensive idea of IMS technology, including the network architecture, characteristics, functions as well as pros and cons of the technology, is profoundly discussed. In the chapter three, the essential function requirement of HSS and the 3G application part of Diameter are introduced briefly. The chapter four illustrates the software architecture of HSS and explicates the function of each submodule in detail. The chapter five explains the implement and optimization of the stack protocol adapter module and the message process module. In the chapter six, based on the the listed testing results, the capability of the system is estimated. Finally, the gains and prospects I have been awarded of in the process of writing this paper are summarized.