一种新的IMS分布式SCIM业务触发机制  

A Novel Distributed SCIM Service Invocation Mechanism in IMS

作　　者：戚琦[1,2] 廖建新[1,2] 朱晓民[1,2] 曹予飞[1,2] 

机构地区：[1]北京邮电大学网络与交换技术国家重点实验室,北京100876 [2]东信北邮信息技术有限公司,北京100083

出　　处：《电子与信息学报》2009年第8期1969-1974,共6页Journal of Electronics & Information Technology

基　　金：国家杰出青年科学基金(60525110);国家973计划项目(2007CB307100;007CB307103);新世纪优秀人才支持计划(NCET-04-0111);电子信息产业发展基金资助课题

摘　　要：IMS(IP Multimedia Subsystem)网络中,S-CSCF(Serving Call Session Control Function)逐次匹配过滤准则的业务触发机制使呼叫信令在S-CSCF与AS(Application Server)之间多次转发,增加了S-CSCF实体的负载压力和呼叫延迟时间。该文在现有IMS业务提供框架的基础上,提出分布式SCIM(DSCIM)业务触发机制,完成了业务流程中AS到AS的连续业务触发,避免了S-CSCF与AS之间信令的往返转发。通过Jackson排队网络理论对业务触发机制进行了数学模型分析和仿真实验,结果均表明DSCIM业务触发机制能够有效降低网络的平均呼叫时延,减轻S-CSCF的负载压力。In the service invocation mechanism of current IMS （IP Multimedia System） network, the Serving-Call Session Control Function （S-CSCF） invokes each Application Server （AS） sequentially to perform user＇s service profile. This mechanism makes SIP request be forwarded excessively among the S-CSCF and Application Servers （ASs）, so it is easy to result in the heavy load of the S-CSCF entity and long call set-up delay. This paper proposes a novel Distributed SCIM （DSCIM） service invocation mechanism. It aims at reducing the call set-up delay in IMS service layer along with decreasing the load of the S-CSCF entity by invoking each AS consecutively without signaling being forwarded back to the S-CSCF. The service invocation mechanisms are modeled through Jackson network and the simulations of different scenarios verify that DSCIM service invocation mechanism can effectively reduce call set-up delay of the network and decrease the load level of the S-CSCF.

关 键 词：IP多媒体子系统 业务触发 DSCIM 呼叫延时 

分 类 号：TN919.85[电子电信—通信与信息系统]