基于混沌预测的IP QoS模型与机制

利用混沌相关理论对具有综合业务应用的IP网流量进行了混沌特性与预测分析，提出了基于混沌预测的IP QoS实现模型与算法。OPNET的网络仿真实验表明，与传统的静态QoS参数配置方法和基于测量的QoS设置方法比较，该模型及方法在网络重负载环境下使各业务的QoS性能指标得到有效改善。     

异构网的QoS参数映射模型和映射方法

针对异构融合网络中不同网络的QoS和映射问题,解决分类和映射方法是提出QoS参数映射模型。在充分研究现有异构网QoS参数映射方法的基础上,提出了QoS参数映射三维模型（Three-dimensional Model for QoS Parameter Mapping,QoS-TMPM）,模型采用颗粒度适中、区分度较大的QoS分类关键参数进行搭建。同时,基于QoS参数映射三维模型的QoS参数映射方法能顺利地完成异构网络间的QoS参数映射,仿真结果表明QoS参数模型和参数映射方法能改善QoS保证服务,从而提高用户的业务体验质量。     

基于QoS参数的ATM网络性能评价模型

该文对ATM网络的CBR、VBR、ABR三种业务类型采用分组延迟时间作为评价指标,考虑到服务质量指标QoS对网络性能的影响,建立了基于QoS参数的ATM网络性能评价模型,并给出了相应的解析式。利用计算机仿真方法对该模型进行仿真试算,结果表明这种性能评价模型基本可用。     

Adhoc网络Internet接入的动态QoS研究

Adhoc与Internet混合网络的QoS策略不同于传统的QoS保障,针对Adhoc与Internet混合的泛在网络有效感知,提出一种新型的Adhoc网络Internet接入的动态QoS模型RATD(ResourceAssignmentandTrafficDetection).该模型通过链路层信号测量激发网络上层的切换决策模块,基于网络接入点QoS状态、信道资源的实时监测与分配、应用业务类别以及呼叫接入方式,对已有的QoS成果进行拓展,提高了接入切换控制的效率,理论分析和仿真实验均验证了RATD模型的有效性.     

多业务IP网络呼叫接纳控制模型和算法

呼叫接纳控制(CAC)是多业务IP网络QoS的关键技术。文章主要研究在采用多协议标记交换(MPLS)传送机制的区分服务(DiffServ)网络中引入带宽代理(BB)资源管理实体条件下的呼叫接纳控制模型和算法。文章在分析比较三类常用呼叫接纳控制技术的基础上,提出了基于参数模型和网络测量相结合的控制模型,给出了该模型的核心控制算法,设计了算法实现流程,并在ns-2.26上进行了仿真实验。仿真结果表明,该文提出的控制模型和算法既能确保各类业务所需的QoS,又能有效地提高网络资源利用率。     

基于广义线性模型的QoE评估方法研究

基于简化的广义线性模型,建立了QoE等级概率分布回归模型。该模型能够通过网络QoS参数映射得到用户QoE等级累积概率分布。采用最大似然估计完成了对模型参数的估计,并使用皮尔逊方法对模型的拟合优度进行了检验。Web业务的QoE评估实例验证了方法的有效性。     

业务感知技术的下一代校园网QoS研究与仿真

基于软交换技术的下一代网络(NGN)具有分组化的、开放的、分层的网络体系结构,是未来网络的发展方向。本文通过研究当前软交换网络QoS的解决方案,提出了基于业务感知技术的贵州大学下一代校园网动态QoS模型。通过在OPNET中建立下一代校园网的网络模型,并对相关业务的QoS性能进行仿真,结果表明业务感知技术能为下一代校园网中的QoS提供一定的保障。     

一种面向业务类别的区分权值异质无线网络选择算法

在以满足业务服务质量（QoS）需求为目标的异质无线网络选择问题中,针对不同类别的业务在QoS需求上的差异,利用层次分析法对3GPP定义的四类业务进行了QoS参数相对重要性分析,设定了每类业务的QoS参数权值,然后基于理想值近似性排序算法,提出了一种面向业务类别的区分权值异质网络选择算法。仿真结果表明,区分权值算法相比平均权值算法而言,前者在满足业务QoS需求的同时,能够更合理地选择目标网络,有效地平衡候选网络负载。     

基于IP网络的QoS测量方法的研究

本文对QoS参数和网络测量进行分析研究,介绍了QoS测量的方法,论述了网络测量的中单向延迟,带宽,丢包率的测量问题,比较主动测量与被动测量的优点和缺点,提出了将主动测量运用到QoS测量上的思路。     

基于速率调整和区分服务的WSN QoS机制

基于排队论对多跳线性拓扑结构的无线传感器网络QoS进行了建模和分析,提出了非端到端的集体数据丢包率CDL和时延CDD的QoS指标的具体公式.进而提出了从Sink节点开始逐级减少的速率调整算法来保证网络QoS.又引入 "区分服务"到本文模型,提出了基于抢先优先制的PPS调度算法以实现不同的业务有不同的QoS参数.仿真表明,速率调整算法能明显提高网络的QoS性能,CDL下降达23.0%～100%,CDD最多减小89.6%,而PPS算法在重要数据的时延CDD和网络抖动等QoS参数上明显优于SATS算法,从而更好地实现了"区分服务"的QoS机制.     

宽带无线系统中的QoS测试技术

分析了宽带无线系统中所承载业务的QoS需求，提出了一种用模拟业务来测试网络QoS的技术。在探讨业务特性参数提取的基础上，实现了VoIP业务在Ixia设备上的模拟过程，并用该模拟数据对Wimax设备进行了测试。同基于实际业务的网络QoS测试技术相比，该技术具有定量性、通用性、灵活性的优点。     

LRT流量对网络QoS的影响

在给定协议的网络环境下,不同网络流量对QoS造成的影响不同,具有LRT特征的网络流量给网络QoS带来的影响较大。分析吞吐量和响应时间与LRT流量之间的关系。利用基于多核技术的网络处理器产生精确LRT流量并对其进行测试,结果表明与平缓流量相比,LRT流量对网络QoS的影响更大。     

Service level agreements (SLAs) parameter negotiation between heterogeneous 4G wireless network operators

We are currently witnessing a growing interest of network operators to migrate their existing 2G/3G networks to 4G technologies such as long-term evolution (LTE) to enhance the user experience and service opportunities in terms of providing multi-megabit bandwidth, more efficient use of radio networks, latency reduction, and improved mobility. Along with this, there is a strong deployment of packet data networks such as those based on IEEE 802.11 and 802.16 standards. Mobile devices are having increased capabilities to access many of these wireless networks types at the same time. Reinforcing quality of service (QoS) in 4G wireless networks will be a major challenge because of varying bit rates, channel characteristics, bandwidth allocation and global roaming support among heterogeneous wireless networks. As a mobile user moves across access networks, to the issue of mapping resource reservations between different networks to maintain QoS behavior becomes crucial. To support global roaming and interoperability across heterogeneous wireless networks, it is important for wireless network operators to negotiate service level agreement (SLA) contracts relevant to the QoS requirements. Wireless IP traffic modeling (in terms of providing assured QoS) is still immature because the majority of the existing work is merely based on the characterization of wireless IP traffic without investigating the behavior of queueing systems for such traffic. To overcome such limitations, we investigate SLA parameter negotiation among heterogeneous wireless network operators by focusing on traffic engineering and QoS together for 4G wireless networks. We present a novel mechanism that achieves service continuity through SLA parameter negotiation by using a translation matrix, which maps QoS parameters between different access networks. The SLA matrix composition is modeled analytically based on the G/M/1 queueing system. We evaluate the model using two different scheduling schemes and we derive closed form expressions for different QoS parameters for performance metrics such as packet delay and packet loss rate. We also develop a discrete event simulator and conduct a series of simulation experiments in order to understand the QoS behavior of corresponding traffic classes.     

A measurement-based approach for dynamic QoS adaptation in DiffServ networks

This paper presents a practical approach to managing multimedia traffic in DiffServ network, using network monitoring feedback and control. We exploit the flexibility of multimedia traffic and process network level parameters to adapt the traffic according to the current state of the network. The latter is determined based on reports sent by bandwidth monitors installed on each node of a DiffServ Domain. The bandwidth monitors interact with a policy server which, depending on the network state, decides the policy(ies) that should be enforced by the DiffServ network. The implementation of the selected policies typically leads to accepting, remarking, or dropping the multimedia traffic entering the network. Multimedia streams may be assigned different levels of QoS, as interpreted by the marker at the DiffServ edge router and marked according to network state. To achieve such dynamic QoS adaptation for multimedia applications, we have implemented and evaluated a policy-based management system. Performance evaluation shows that multimedia applications adapt better to network conditions using our approach.     

基于Linux的流量控制机制研究

为实现QoS,网络节点必须具有流量控制的能力。Linux从内核2.2版起就增加了对网络QoS的支持,并提供了一套强大的流量控制功能。本文首先分析了Linux的协议体系结构、数据传递机制和数据转发过程,再介绍了流量分类、队列管理、流量整形和流量监测等技术,得到了Linux下流量控制机制的原理。     

基于聚集流量分类的流量型DoS攻击防御方法

提出一种基于主机服务状态检测和关键流量识别的聚集流量细粒度分类、识别及控制方法,并在可控网络上实现基于此聚集流量分类的流量型DoS攻击分布式检测和防御.该方法利用攻击检测感知器和控制路由器间的安全通讯协作,通过调整控制路由器集上的聚集流量分类策略和Rampart控制机制对一般聚集流量的控制力度,使得被保护主机及其网络在受到流量型DoS攻击的情况下,其负载和拥塞程度仍可以稳定在一个正常的范围内,从而有效地保证关键聚集流量服务请求的QoS需求.     

数字家庭网关上网络QoS算法的研究

家庭网络中数字家电种类繁多,而且随着多媒体设备越来越多、功能越来越强,对服务质量（QoS）管理提出了更高的要求。现有的QoS架构中存在很多流量管理方面的问题,如低优先级流量饿死、拥塞、流量优先级指定等。通过分析比较各种QoS架构的优缺点,提出一种数字家庭网关上的网络QoS算法。采用带宽控制、准入控制、优先级验证等机制,从网络流量管理角度解决QoS问题,并通过模拟分析证实了该QoS算法的有效性。     

Traffic specifications for the transmission of stored MPEG video onthe Internet

Guarantees of quality-of-service (QoS) in the real-time transmission of stored video on the Internet is a challenging task for the success of many video on demand (VoD) applications. Two QoS classes have been specified by the IETF Integrated Services (intserv) Working Group: Guaranteed Services and Controlled-Load Services. For both of them, it is necessary to provide traffic sources with the capability of calculating the traffic characteristics to be declared to the network, Tspec, on the basis of a limited set of parameters statistically characterizing the traffic and the required level of QoS. The target of this paper is to develop an algorithm for the evaluation of the Tspec parameters which characterize the video stream when a given QoS is required. To this end an analytical framework modeling an MPEG stored-video server and the access network node is introduced. The video emission process is modeled with a switched batch Bernoulli process (SBBP), and performance in the video-server smoother is analytically evaluated. Then the token bucket at the network access point, loaded by the output traffic of the video-server smoother, is modeled to calculate the probability of marking nonconforming data packets