Study On Next Generation Network Evolving From Softswitch To Ims

With the development of IP technology and broadband networks, the traditional telecommunications network which is based circuit-switch is gradually shrinking. The current soft-switch system has an basic capacity of broadband services (VoIP and text messaging), but the limited capacity of multimedia services can not meet the developing requirements of multimedia services.International carriers are faced with reduction of fixed network users,evolution from narrowband to broadband, core network's convergence of fixed-mobile and other issues. They all believe that IMS is the direction of the core network's development, and have launched lab trial.With the reconstruction on Chinese carriers completed, the three carriers all have the capacity of mobile and fixed network operating and serving.They hope to expanse the broadband service to meet the market's requirement, and want to build a broadband multimedia service system which converge the mobile and fixed network. The focus of all service is gradually shifted from the voice to multimedia. How to evolve from softswitch to IMS networks smoothly has attracted everyone's attention.Chapter 1 of this paper introduced the background of Next Generation Network evolving from Softswitch to IMS,purpose of this study, and what I have done in this study; chapter 2 described the basic concept of the NGN and the architecture of the system; chapter 3 compared the softswitch with IMS system, analyzed the evolution's necessity from softswitch to IMS;chapter 4 comparatively analyzed the strengths and weaknesses of the evolution programs, combined with the condition of the current telecommunications network to select the appropriate network evolution of the programs; chapter 5 described the core-network evolution in detail;chapter 6 summarized the fulltext.