QoS调度机制在EVDO Rev A网络中的研究分析

本文首先介绍了EVDO Rev A网络中实施QoS的重要意义、评价指标,分析了QoS的服务模型,深入研究讨论了EVDO Rev A系统中QoS的控制机制及调度算法,最后总结了QoS调度机制在EVDO Rev A网络运行中的应用.     

摩托罗拉推出基于CDMA 1x EVDO Rev A技术的新一代无线一键通解决方案

摩托罗拉公司日前宣布，公司推出了专门为具备EVDO Rev A数据功能的CDMA 1x网络而优化设计的新一代无线一键通（PoC）解决方案。该解决方案充分利用了CDMA 1x EVDO Rev A标准所提供的更为完善的功能特性，其中包括更高的数据速率、更短的呼叫建立延迟时间及更好的服务质量（QoS）等。     

EVDO RevA网络QoS实现机制的研究分析

本文首先介绍了EVDO Rev A网络中实施QoS的重要意义、评价指标以及关键参数,分析了QoS的业务模型,从QoS架构、无线RAN和核心网深入研究了EVDO Rev A网络中QoS的实现机制,最后总结了QoS调度机制在EVDO Rev A网络运行中的应用。     

车载双模无线视频监控系统的设计与实现

设计并实现了一种基于WCDMA和CDMA2000 EVDO无线3G网络的车载式双模无线视频监控系统。介绍了车载式视频监控终端嵌入式设备的整体硬件结构,以及相应功能模块定义和说明。从系统总体结构、主要流程图和关键技术等方面详细描述了监控中心的软件实现。测试结果表明,该车载式监控系统充分利用WCDMA和CDMA2000 EVDO双模网络进行数据传输,相比于传统单模视频传输系统,有效提高了视频传输质量。     

朗讯领跑CDMA2000 EV-DO Rev.A

近年来，CDMA2000EV—DO网络发展迅猛，截至今年3月，全球已有38家移动运营商提供CDMA2000 1x EVDO商用服务，有41个1x EV—DO网络计划于年内商用，1x EVDO用户超过2400万。目前大规模商用的版本是EV—DO Rev．0，下行速率高达2．4Mb／S，上行速率只有153．6kb／S，缺乏相对完善的QoS机制。随着用户的增长和业务的开展，市场越来越希望EVDO网络能加强对低时延、高实时性业务的支持，如可视电话、高实时性在线游戏、VoIP等。     

EVDO intra-user QoS分析及应用

主要介绍EVDO intra-user QoS的原理,包括其流类型、空口消息,并以Qchat实例的实现来分析Qos的实现过程和流程。通过文章的介绍,读者可以应用Qos原理优化CDMA网络、分析解决问题,从而提升3G业务的性能,提高网络质量和用户感受。     

模型校正与高铁优化覆盖

高铁覆盖切换快、周围环境复杂多变.通过对某省市境内高铁沿线传播模型的校正并通过CDMA(code division multiple access)网络EVDO(evolution-data optimized,演进数据最优化)信号的仿真,分析了影响CDMA网络EVDO数据信号的指标参数.结合实际网络特点,通过网络仿真分析并调整实际工作参数,得到指导高铁网络建设的方法,应用于高铁网络建设的优化.     

基于多无线接入网络的可视电话应用系统设计

本文描述了一种新型的可视电话应用系统,该系统基于Qualcomm的Brew平台,支持多无线接入网络的无缝切换,使用高速接入网络CDMA EVDO Rev A并具有Qos支持,文中主要介绍了其体系结构中的核心模块,包括:应用层,多无线接入框架层等,最后介绍了该可视电话应用的QoS保障。     

高铁CDMA网络EVDO信号分析

高铁覆盖具有切换快、周围环境复杂多变的特点。文章通过对某省境内高铁沿线CDMA网络EVDO信号的仿真,分析了影响CDMA网络EVDO数据信号的指标参数。结合实际网络特点及网络仿真分析并调整实际工程参数,得到指导高铁网络建设的方法,应用于高铁网络的建设优化,对于我国高铁数据网络建设有参考意义。     

CDMA EVDO精细化网优可行性分析

在CDMA系统中,EVDO能提供更高速率的数据业务,从而提高使用者的用户体验,因此,保障良好的用户感受,提高网络性能指标是EVDO网络优化工作的重点。文章以EVDO相关技术为基础,通过分析现阶段EVDO网络的优化特性、用户特性、影响关键性能指标及用户感知的因素,确定EVDO现网的精细化网优思路,并在广东汕头市的EVDO网络中进行优化探索,取得了显著的优化效果,验证了EVDO精细化网优的可行性,在EVDO优化工作中具有一定的借鉴意义。     

第三代移动通信中的服务质量及技术挑战

第三代移动通信(3G)系统将Internet和移动通信相结合，使得移动通信中业务的数量和种类得到前所未有的增长。各种实时和多媒体业务的不断涌现，要求提供端到端的服务质量(QoS)保证。与Internet相比，3G系统中的QoS具有自身的特点，给3G系统QoS的实现带来更大的技术挑战。本文总结了这一领域近年来众多的研究成果，对实现3G系统中的QoS所面临的挑战进行分析，指出了几种技术解决途径，提出了无线接口的QoS实现框架，最后展望了3G的未来及支持QoS的技术发展方向。     

Managing IP traffic in radio access networks of next-generation mobile systems

The strong research, standardization, and development activity currently focusing on the enabling technologies for the transition to a new generation of mobile networks represent a great opportunity to accomplish the goal of IP multimedia service provisioning to mobile users. This will contribute to the migration toward an all-IP platform with guaranteed end-to-end QoS provisioning, and will definitively fuel the deployment of new multimedia mobile applications and the further development of multimedia ubiquitous communications. This objective is not easily achievable, mainly due to the difficulties in handling IP multimedia applications in a mobile environment with a guaranteed QoS level. To contribute to this issue, in this article we discuss an evolutionary scenario from the current UMTS system to a next-generation QoS-aware mobile platform based on IP as the transport solution in the radio access network, UTRAN. Furthermore, we propose to fit the IntServ-over-DiffServ approach, in order to best manage the QoS level inside the UTRAN.     

Multimedia friendly home wireless LANs

Home wireless local area networks (LANs) will carry diverse multimedia applications such as data, video, voice, and time sensitive control information. To enable quality delivery of such applications, these networks should incorporate an efficient quality of service (QoS) support mechanism. However, existing home wireless LANs do not provide support for multimedia applications. In this paper, we introduce our software based solution that provides QoS support for voice, video and data while using existing wireless home networks. The experimental results we have obtained provide evidence that our solution provides QoS support for multimedia applications.     

NOVEL MULTIMEDIA TRAFFIC MODELING BASED CAC SCHEME FOR CDMA COMMUNICATION SYSTEMS

As the radio spectrum is a very scarce resource, the Call Admission Control （CAC） is one of the most important parts in radio resource management. The Code Division Multiple Access （CDMA） based next generation wireless communications systems will support the transmission of multimedia traffic, such as voice, video and data, thus the CAC, which can support the multimedia traffic and guarantee the Quality of Service （QoS） of different traffic, has gained broad attention. In this paper, a novel multimedia traffic modeling method and a corresponding dynamic QoS based CAC are proposed. The analysis and simulation results show that the proposed CAC scheme can guarantee the QoS to different traffic demand, and improve the system performance significantly.     

基于IMS的计费机制

3GPP在2002年启动的R5版本中为GPRS/3G网络设计了基于IP传输之上的标准化的多媒体解决方案IMS,其方案内容包括安全功能、计费功能、漫游功能和服务质量(QoS)等。2004年的3GPP R6版本对该计费功能进一步完善,定义了一个独立的功能强大的计费体系。该体系主要采用两种计费机制:离线计费和在线计费。本文将对这两种计费机制的结构及各功能实体进行分析,简述其计费过程,并提出该计费体系存在的局限性以及以后可能的发展方向。     

A Bandwidth Control Method Providing Entrance QoS for Multimedia Communication

1 Motivation Nowadays , the QoS provided by the wideband IPnetwork starts at an edge-router and ends at anotheredge-router .Therefore ,the trunk QoSisfinished,suchas RSVP[1]and DiffServ[2].In order to complete theend-to-end QoS,the mechanism of entrance QoS (thebandwidth controller) is introduced. As Fig.1 shows ,if the bandwidth controller circledby the dashed frame is not used,the Ethernet is con-nected with the router directly through 100 Mbit/sbandwidth. Then this router is connect…     

一种新的对称CDMA系统中非对称业务下的呼叫允许控制策略

未来无线多媒体网络将以分组技术为基础,支持多种业务的传输,业务的QoS保证将受到一定的挑战.各运营商也将针对自己所服务的对象特点,定义各类业务的QoS等级,来提供具有不同QoS要求的业务.因此,呼叫允许控制(Call Admission Control,CAC)策略将要以分组业务为主要对象,即既要在充分利用系统资源的基础上保证各业务的QoS要求,又要适应各运营商之间的不同需求.因此本文提出一种新的对称CDMA系统中非对称业务下基于动态QoS保证的CAC策略.各运营商可根据自己的要求定义各业务的QoS等级.由于业务的不同特性,使得网络中上行链路和下行链路的业务呈现不对称性,为避免资源的浪费,将根据网络中的资源占有情况动态的地分配上行和下行链路中的资源.仿真结果表明,该策略可以自适应地保证各业务的QoS要求,提高了业务间的公平性和系统资源的利用率.     

Policy-based QoS architecture in the IP multimedia subsystem of UMTS

The third-generation mobile system, or Universal Mobile Telecommunication System, will offer IP-based multimedia applications and services with end-to-end QoS guarantee. The key part providing these services is the policy-based QoS control architecture in the IP multimedia subsystem (IMS). In this tutorial we describe the network entities involved in the policy-based QoS architecture, their interactions to realize guaranteed QoS in the UMTS network, and the communication interfaces employed in the interactions.     

Priority-determined multiclass handoff scheme with guaranteed mobile QoS in wireless multimedia networks

The provision of multiclass services is gaining wide acceptance and will be more ubiquitous in future wireless and mobile systems. The crucial issue is to provide the guaranteed mobile quality of service (QoS) for arriving multiclass calls. In multimedia cellular networks, we should not only minimize the dropping rate of handoff calls, but also control the blocking rate of new calls at an acceptable level. This paper proposes a novel multiclass call-admission-control mechanism that is based on a dynamic reservation pool for handoff requests. In this paper, we propose the concept of servicing multiclass connections based on priority determination through the combined analysis of mobile movement information and the desired QoS requirements of multimedia traffic. A practical framework is provided to determine the occurrence time of handoff-request reservations. In our simulation experiments, three kinds of timers are introduced for controlling the progress of discrete events. Our simulation results show that the individual QoS criteria of multiclass traffic such as the handoff call-dropping probability can be achieved within a targeted objective and the new-call-blocking probability is constrained to be below a given level. The proposed scheme is applicable to channel allocation of multiclass calls over high-speed wireless multimedia networks.     

QoS-based routing of multimedia streams in computer networks

Continuous media such as audio and video require a certain quality-of-service (QoS) when transferred through computer networks. The selection of a network route for a particular media stream should hence take into account which route is best-suited for providing this QoS. QoSFinder is a method for QoS-based routing of multimedia streams. It is based on a path vector protocol that takes into account throughput, delay, and loss rate of individual route segments. A simulation of QoSFinder shows that its heuristic is superior to metrics that are only based on one of these parameters. QoSFinder increases the probability of finding suitable paths through networks for distributed multimedia applications