固网软交换向IMS演进方案

固网软交换向IP多媒体子系统(IMS)演进应采用合理的方法、步骤和策略。演进可以在继承原软交换(SS)公共交换电话网络业务仿真子系统(PES)业务功能的前提下,平滑地向IMS演进,逐步引入、扩展多媒体和移动业务,实现核心网层面的固定和移动融合(FMC)。下一代网络(NGN)核心控制层的软交换和IMS在基本架构上没有实质冲突,软交换主要面向公共交换电话网(PSTN)仿真业务,而IMS为实现FMC和多媒体业务,在移动性、安全、服务质量(QoS)、开放业务架构等方面作了有益的扩展,软交换向IMS演进在技术上是完全可行的。对于已经采用软交换的运营商,采用演进的方式实现基于IMS的全业务的NGN网络,可以节约投资,减小网络改造风险,降低运营成本。

Evolution from Fixed Softswitch to IP Multimedia Subsystem

The evolution from fixed Softswitch to IP Multimedia Subsystem (IMS) requires reasonable methods, steps and strategies. IMS as a smooth evolution can preserve the Softswitch-based PSTN Emulation Subsystem (PES), and realize Fixed and Mobile Convergence (FMC) at the core with the introduction an proliferation of multimedia and mobile services. Therefore, Softswitch as the core control layer of Next Generation Network (NGN) is not contradictory with IMS as it can be mapped into the IMS architecture. While Softswitch can provide PSTN emulation services, IMS mainly designed for FMC and multimedia services is capable of supporting mobility, security, QoS and open services architecture. The evolution from Softswitch to IMS is technologically feasible. For operators who have already adopted Softswitch technology, they can evolve their networks to IMS-based full-service NGN, to reduce their investments, risks of network modification, and operational costs.