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

IP Multimedia Subsystem is a major component of the core network in third generation mobile communications, proposed by 3G Partnership Project (3GPP) in Release 5. IMS is based on IP Bearer Network, its control protocol is SIP (Session Initiation Protocol), and it controls IP multimedia services. IMS, which consists of a number of functional entities. The major entitys are Call Session Control Function (CSCF), Home Suscriber Server (HSS), Media Gateway Control Function (MGCF), Application Server (AS) and intelligent terminals.IMS HSS is like a database which stores all the relevant data of users and services. The data stored in HSS include user identities, user registration information, access parameters, service profiles, and transparent service data.Firstly, this paper will introduce the third generation mobile communications (3G) and IMS background knowledges, including the evolution of 2G to 3G, IMS architecture, and IMS related protocol such as Session Initiation Protocol (SIP), Diameter protocol, give details of the location of HSS in the IMS network, interfaces between HSS and other IMS network elements, the main functions of HSS, the scenarios and call flows. Secondly, according to HSS specific functional requirements, this paper presents a design basis and the HSS database design. Then, the HSS system design, and the database adapters (DBA) module design and interfaces design. In addition, the paper also gives details of HSS functional testing and analyzing. Finally, this paper gives a summary, and also gives some suggestions of how to improve the function of current database and database adapter module.IMS HSS stores all relative data of users and services, so it occupies a very important position in the IMS network. The research and development of HSS is of great significance for the research and development of IMS.