【作者】 戴民；

【导师】 杨放春；

【作者基本信息】 北京邮电大学 ， 计算机科学与技术， 2007， 硕士

【摘要】 基于IP等分组交换技术的下一代网络(NGN)的核心特点是开放与融合。IP多媒体子系统(IP Mutilmedia SubSystem，简称IMS)采用分层的开放体系架构，实现了接入技术无关、统一的会话控制和用户数据、开放和统一的应用平台等特性，不仅为移动网络融合到全IP网络提供了统一的业务控制平台，并且被公认为是移动-固定网络融合(FMC，Fixed-Mobile Convergence)以及电信网-Internet融合的基础，是下一代网络(NGN)的控制核心。通过IMS可以实现真正的从业务、设备到网络的完全融合。CSCF(Call Session Control Function，呼叫会话控制功能)位于IMS核心控制层面，是IMS系统中完成会话控制功能的组件，是整个IMS系统的核心功能实体，也是实现IMS业务与控制分离、控制与承载分离思想的最为重要实体。研究CSCF的功能，设计并实现CSCF实体，对于理解IMS系统的原理，发现其标准化过程中的问题并提出解决方案从而促进IMS系统向更为完善的方向发展有十分现实的意义。本文沿着为什么IMS，IMS是什么，怎样实现IMS，IMS如何发展的思路展开了对IMS系统的研究。论文首先从对IMS系统的背景研究入手，分析了IMS产生的原因，介绍了IMS的相关概念和体系架构的重要思想。第二部分以IMS核心的协议技术为重点，介绍了互联网协议在IMS系统中的应用，突出了IMS实现移动网络-互联网，以及固网-移动网融合的特点。第三部分对引入了所要实现IMS软件系统，并对核心功能实体CSCF的功能需求进行了分析。第四部分详细介绍了如何基于TAPA(Trillium Advanced PortableArchitechture)架构设计一个通用的CSCF实体功能及软件框架。并详细的介绍了各个功能模块的功能和设计思想。第五部分是本文的重点部分，详细的介绍了如何在第五部分描述的CSCF通用框架上实现一个具有基本功能的S-CSCF功能实体，包括各个各核心功能模块的设计思想和实现方法，以及模块间如何协作以完成S-CSCF的核心功能。最后对S-CSCF实体在IMS系统中的实现和测试情况进行了介绍。第六部分是总结部分，总结了本文的成果并列出了一些需要进一步研究和改进的问题。更多还原

【Abstract】 The key feature of IP-based Next Generation Network(NGN) is being open and convergence. The IP Multimedia Subsystem which adopts a layered open architecture realizes features of access independence, unified session and user data control, open and unified service platform, etc., which makes IMS not only a unique service control platform for converging into All-IP network, but also the foundation to realize FMC(Fixed-Mobile Convergence)and the convergence of Telecom and Internet. IMS has been considered as the heart of NGN, through which, convergence from services, equiments to network can be truely realized.CSCF (Call Session Control Function) is the core functional entity of IMS which implements the function of session control and management. CSCF realizes IMS’s key idea of independence between service and control layer and separation of control and underlying transport layer,which makes the research, design and implementation of CSCF very significant to the development of IMS.In this paper, research on IMS follows the sequence of why IMS, what is IMS, how to realize IMS and how to develop IMS.The paper starts with the introduction of the background of IMS, including the analysis of the emerging of IMS, key concepts of IMS and important ideas of the IMS architecture.In the second part, key protocols of IMS are introduced, including how these Internet protocols work and IMS’requirements on these protocols, which helps to understand the reason why IMS is the key to realize the convergence of mobile network and the Internet.In the third part, the IMS software system is introduced, and the analysis of functional reqirements of IMS’s core entity-CSCF is conducted.The forth part presents how to design a general framework of CSCF based on TAPA (Trillium Advanced Portable Architechture) ,and describes functions of each module and the idea of its design in detail.The fifth part is the key part of this paper, which comprehensively describes the design and implementation of a real S-CSCF entity based on the framework introduced in the last part.The design priciple and implementation method of each module are presented very clearly, the collaboration of all the key modules to realize S-CSCF’s core function is also described. At last, results of a live test of S-CSCF entity is presented.The sixth part is the summary of this paper, which concludes all the achivements of the research and lists some of the points that need to be considered to further develop IMS.更多还原