IMS中基于策略的QoS管理机制

IP多媒体子系统是由3GPP标准化组织在R5版本中提出的一个提供IP多媒体业务的体系架构。其显著的特点是基于SIP的会话控制和与接入技术无关性,但难以提供端到端的QoS保证,为此,R6版本做了进一步修正,在IMS中引用了基于策略的QoS管理机制。文章介绍了IMS体系架构和主要的功能实体,分析了IMS系统中基于策略的QoS管理架构,详细描述了IMS会话建立过程中端到端的QoS流程,最后对IMS承载网的QoS机制进行了分析,并就IP QoS如何进一步支持IMS端到端QoS保证提出了建议。

Policy based QoS management mechanism in IMS

IMS was defined by 3GPP in release 5.Although it has the characteristics of SIP based session control and access-irrelevant,it can not give an end-to-end QoS guarantee.So it has been modified in the release 6 based on the old edition.This paper introduces overall architecture of IMS and its important functions,analyzes the policy based QoS management function and the end-to-end QoS flow in the procedure of IMS session setup in detail,discusses the QoS mechanism in IMS network,and finally gives some suggestions about IP QoS in IMS.