【作者】 杨军；

【导师】 杨学军； 王芙蓉；

【作者基本信息】 华中科技大学 ， 通信与信息系统， 2004， 硕士

【摘要】 本文结合作者在3G核心网电路域的产品研发经验,研究了软交换技术中与承载控制分离的呼叫控制的相关问题,包括软交换网络的组网、IP电话的路由、媒体网关的选择,以及如何通过媒体网关控制协议(H.248/MEGACO)控制媒体网关实现承载控制的功能等。基于IETF提出的IP电话路由协议(TRIP协议),在电信网络中引入“管理域”的概念和位置服务器(LS),本文首先提出了一般软交换网络的组网及电话路由策略,然后重点针对3G核心网电路域的网络组网特点以及所采用的特定通信控制协议,研究了电路域的组网、电话路由,以及媒体网关的选择。在软交换网络中引入TRIP协议,可以简化网络的组网和网络的运营维护管理,实现动态的电话路由,提高网络性能,并且适应未来网络融合的趋势。对于媒体网关的选择,本文基于H.248协议的资源拥塞控制包和过载控制包,提出了媒体网关的呼叫接纳控制策略,并对该策略进行了初步的OPNET仿真,仿真结果表明,应用了该策略后,在保证比较高的呼叫接通率的同时保证了网络的性能。本文最后研究了通过媒体网关控制协议实现媒体网关的控制方法,提出了在MSC Server中对媒体网关中上下文和承载终结点的标识方法,基于该方法,可以实现可扩展的、模块化的媒体网关控制功能,简化了呼叫控制逻辑的设计,并可在一定程度上提高呼叫的接续速度。更多还原

【Abstract】 Based on the experiences in the research and development of circuit-switched (CS) domain of 3G core network, this document discussed the problems relevant to the bearer independent call control in soft-switched system, including the architecture and telephony routing of soft-switch network, media gateway (MGW) selection and how to control the MGW to realize the bearer control through MGW control protocol.By introducing Location Server (LS) and the concept of administrator domain into the telecomm network, IETF’s TRIP-based architecture and telephony routing strategies of general soft-switch system were promoted. Then, aiming at the network characteristics and the control protocols adopted by the CS domain, the architecture, telephony routing and MGW selection of CS domain were studied. By adopting TRIP protocol in soft-switch system, the network architecture and network operations were simplified, dynamic telephony routing could be implemented, the capabilities of the network were improved and the trend of network convergences could be adapted.As to MGW selection, based on the resource congestion control package and overload control package of H.248 protocol, the call admission control (CAC) of MGW was discussed, and simple OPNET simulation of MGW CAC was described. The result of the simulation indicated that the application of MGW CAC ensured higher call success ratio and better network capability at the same time.In the last part of this document, MGW control was studied, and the way for MSC Server to identify the context and termination in MGW was introduced. By this way, the implementation of extensible, modularization MGW control functions was possible, and the logic of call control could be simplified, and, to some extent, call establishment was accelerated.更多还原