基于策略的平流层通信系统QoS映射机制研究

【作者】 王莹；

【导师】 郭伟；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2011， 硕士

【摘要】 平流层通信系统是将基站放置在20-50kM的高空平流层高空平台上,有着可快速部署、支持突发通信能力、抗干扰能力强、覆盖区域大、应用方式灵活等特点,它继地面移动通信系统和卫星通信系统之后成为第三个无线通信系统,有着重要的战略意义和广泛应用的潜力。随着各类多媒体业务的出现,业务类型越来越丰富,特别的针对多媒体用户,实时性的高要求,希望可以获取专用带宽、较小时延以及较低丢包率,于是有了QoS(服务质量)概念的提出及其各种相关技术的研究。同时要使用户在不同网络融合的环境下实现多媒体通信,需要统一的QoS架构及机制来协调。平流层通信系统有其特定的接入子系统及QoS需求,需要提供基于IMS的统一QoS保障。本文针对系统单平台情况下的QoS需求,研究了最新标准核心网中IMS基于策略的QoS框架PCC、QoS机制和基于QCI标识的QoS参数体系,无线接入子系统中基于不同业务等级参数的5种调度方案及基于业务流的QoS机制。无线接入子系统作为一种非3GPP的接入技术接入核心网,本文对其QoS保障提出了一种框架,并将其中基于策略的QoS保障机制提炼为一种域间策略形成和本地化获取的过程。设计了策略形成网络单元PCRF和策略本地化网络单元A-PCEF的细化功能模型,并提出了一种信令映射方案;接着对PCRF中基于业务类型的策略形成QoS映射和A-PCEF中策略本地化的QoS映射进行了设计,其中策略本地化基于域间QoS不同参数体系的标志性QoS参数作为映射索引的思想,最后阐述了总体QoS机制在系统会话流程中的实现。本文针对提出的系统QoS保障框架,在网络仿真软件OPNET Modeler 14.5中搭建网络仿真场景,并对策略形成单元及域间策略本地化获取单元进行了模块化设计仿真,通过各典型业务的吞吐量、时延、丢包率等性能指标的数据曲线,证明了本文QoS保障机制及映射方案的可行性,并为后续的QoS研究及系统的实际实现提供了理论及数据基础。更多还原

【Abstract】 Stratosphere communication system has its base station on the 20-50km High Attitude Platform Station,whose characteristics are Rapid deployment,emergency communication ability,strong anti-interferene capability,large regional covering and flexibly applied patterns. It becomes the third kind of network following the the satellite network and ground network ,with important strategic significance.With the emergence of various multimedia services, service types are more and more abundant,specifically the multimedia user, Due to the high real-time requirements,services have special demand for throughput, delay, jitter and packet loss rate.Then research of QoS concept and the related technolies emerge. Stratosphere communication system also has its QoS requirements, exactly to provide integrated QoS guarantee based on IMS.This paper studies the IMS PCC framework,mechanism and parameter system based on QCI in the latest standard core network,as well as the five schedule types based on service flow and the QoS mechanism in the wirless access network. As a non-3GPP access technology to the core network, a kind of QoS guarantee framework is put forword,and the paper highlights the QoS mechanism as a generation of policy and localization of the policy in different areas.According to the focus point, this paper designs the network element PCRF and the A-PCEF,and presents a scheme for signaling mapping. Following the design of QoS mapping based on service type in the policy generation element and the QoS mapping in the policy localization element,Policy localization has its symbolic QoS parameter in different areas as the index to complete the mapping.Finally,this paper Expounds the overall QoS mechanism in the system to achieve the session procedure.Then according to the QoS guarantee framework,the simulation scene is built in network simulation software OPNET Modeler 14.5 with the modeling design of network element PCRF and A-PCEF. By the means of the simulation data and curves of throughput ,delay and packet loss rate, it is proved that the QoS mechanism and mapping scheme are feasibility,as well as provides a reference theory and data for the following QoS research and realization of the actual system.更多还原