基于IP分布式MSC的CDMA2000系统A接口设计与实现

针对传统集中式移动交换中心(MSC)容量小、安全性低、不易扩展的不足,基于IP技术和软交换技术,提出了一种分布式MSC架构.在此架构下对A接口协议进行了分析并给出了基于IP的实现方案:兼顾TCP的可靠性和UDP的简洁性定义了承载A接口中的信令和业务的一个增强性UDP协议(EUDP).此外,也描述了分布式MSC负荷分担的选择原则:轮选、处理最近和资源最近;最后以8 kbit/s语音业务为例,对基于IP传输语音业务的带宽需求进行了简单分析.实践表明,该方案不仅提高了系统的经济性,也改善了网络容量扩展和新业务提供的灵活性.

Design and Implementation of the A-Interface in a Distributed MSC for CDMA2000 System over IP

Based on the techniques of IP and soft switch,this paper proposes a novel distributed MSC architecture,which solves the problems of low capacity,low security and less expansibility in traditional MSC.After analyzing the protocol of A-interface,a new design scheme is put forward based on IP:an enhanced UDP protocol(EUDP)is defined to combine the reliability of TCP and the simplicity of UDP,which provides a bearer for traffic of call messages and service data described in A-interface;the choice criteria in distributed MSC such as polling,procession nearest and resource nearest is also described.Finally,with the example of 8kbit/s voice service,the demand for bandwidth based on IP is analysed.The practice demonstrates that the scheme can not only improve its availability but also enhance the flexibility of expanding the capacity and providing new services.