Study On Softswitch In Telephone Network Application And Its Evolution To IMS

This thesis mainly studies on the Softswitch technology of NGN and its practical applications. It discusses the evolution of Softswitch technology development process, basic concepts, architecture, common agreements, and finally analyzes the Softswitch technology in PSTN and PLMN practical cases, prospects the evolution of the existing Softswitch network to the IP Multimedia Subsystem (IMS) and how to realize Fixed and Mobile convergence (FMC).Firstly, the paper mainly focuses on Softswitch technology in PSTN and in-depth analyzes its three main application scenarios:1)the use of standard TDM softswitch tandem office equipment replacement to complete transformation of PSTN intelligence,2)Softswitch technology using long-distance telephone network architecture to achieve a flat,3) Softswitch as the end office switching equipment to manage voice user and the IP transformation of fixed-line access layer. Two ways are demonstrated to access SHLR and two exchange methods with SHLR on singals as well as their advantages and disadvantages. This thesis also analyzes the application of 3G CDMA2000 based on the development of mobile softswitch and its architecture. Then, it focuses on the Softswitch direction to FMC, describes not only the development and architecture of IMS, but also protocols and Fixed Softswitch and Mobile Softswitch in IMS evolution with each step, route and IMS-based FMC vision. The thesis is based on the realword application from Gansu China Telecom Corporation of Softswitch technology, the specific Softswitch technology is introduced in PSTN end office, tandem office, long distance bureau and 3G CDMA2000 mobile Softswitch network in the actual building program and scenarios, and strive to integrate theory with practice, through comparison of the Fixed and Mobile Softswitch, which draws on the conclusion that the Softswitch-based fixed and mobile convergence is feasible and practical.