中文摘要：

提出一个3G核心网络体系结构能力增强方案，引入两个功能实体：MMS与ACS，分别完成安全类服务与位置类服务．增强的核心网络扩大了网络容量，提高了网络实体可靠性，增强了网络对于位置类服务以及安全类服务的支持能力，同时有利于各种控制功能的独立演进．使用M／D／n排队模型分析了增强前后的网络，收集并比较了排队长度、消息延迟、呼叫延迟三个性能参数，理论分析与仿真结果验证了此增强方案的有效性与可行性．

英文摘要：

Multi-subsystems coexist in 3G core network and same functions are provided redundantly. This paper proposes an enhanced core network architecture by introducing two separate servers called MMS （ Mobility Management Server） and ACS （Access Control Server） which are used to provide mobility and security services respectively. The enhanced core network enlarges the system capacity, enhances the systemg capability on supporting mobility and security services, degrades the entity ＇s complexity and facilitates the independent advancement of those control logics. Both core networks are analyzed with M/D/n infinite buffer queuing system based on the assumption that state transitions occur at departure points. The departure point queue length distribution, average queuing delays and average call processing delays are obtained and compared. The results validate that the enhanced core network architecture is efficient and practicable.