Evolution from Fixed Softswitch to IMS  

作　　者：Tu Jiashun Yang Wei Gao Yi (Network Division of ZTE Corporation,Nanjing 210012,China) 

出　　处：《ZTE Communications》2007年第2期20-24,共5页中兴通讯技术（英文版）

摘　　要：Reasonable steps,measures and strategies should be chosen for the evolution from fixed Softswitch to the IP Multimedia Subsystem (IMS). A smooth evolution to the IMS is possible by gradually introducing and expanding multimedia and mobile services to achieve Fixed Mobile Convergence (FMC) at the core network layer while leveraging the existing SS-based Public Switched Telephone Network Emulation Subsystem (PES) service functions. The core control layers of the Next-Generation Network (NGN),SS and IMS have basically identical architectures. However,SS is oriented to PSTN emulation services while the IMS makes a useful expansion in terms of mobility,security,Quality of Service (QoS) and Open Service Architecture (OSA) to enable FMC and multimedia services. Therefore,the evolution from SS to IMS is technically feasible. Operators who have already used SS can enable IMS-based full-service NGN through the evolution,which not only saves the investment and operation costs,but also reduces the risk of network alteration.Reasonable steps,measures and strategies should be chosen for the evolution from fixed Softswitch to the IP Multimedia Subsystem (IMS). A smooth evolution to the IMS is possible by gradually introducing and expanding multimedia and mobile services to achieve Fixed Mobile Convergence (FMC) at the core network layer while leveraging the existing SS-based Public Switched Telephone Network Emulation Subsystem (PES) service functions. The core control layers of the Next-Generation Network (NGN),SS and IMS have basically identical architectures. However,SS is oriented to PSTN emulation services while the IMS makes a useful expansion in terms of mobility,security,Quality of Service (QoS) and Open Service Architecture (OSA) to enable FMC and multimedia services. Therefore,the evolution from SS to IMS is technically feasible. Operators who have already used SS can enable IMS-based full-service NGN through the evolution,which not only saves the investment and operation costs,but also reduces the risk of network alteration.

关 键 词：Evolution from Fixed Softswitch to IMS MGCF PSTN CSCF 

分 类 号：TN919.8[电子电信—通信与信息系统]