A CORBA-based quality of service management framework fordistributed multimedia services and applications

For distributed multimedia services, it is essential that quality of service be guaranteed system-wide, including end systems, communication systems, and networks. Although many researchers have addressed issues of QoS management, little attention has so far been paid to the QoS management services in distributed multimedia services and applications. To address this deficiency, we have designed a layered model for end-to-end QoS management called the QoS management framework. Our framework, which is CORBA-based, includes a generic QoS MIB for the QoS parameterization of various multimedia services and the services needed to perform various QoS functions. A key component of this framework is the QoS management service object (QMSO), which orchestrates resources at endpoints, coordinating resource management across layer boundaries. Services such as translation, monitoring, admission, and negotiation are provided by the QMSO. To validate this concept, we have developed a QoS management system for managing and controlling the QoS of a distributed multimedia system called MAESTRO. The QoS management system has been implemented through CORBA objects and provides an interface to multimedia applications, which can be dynamic negotiation and renegotiation of QoS by users. Some performance results in QoS negotiation and renegotiation are also presented     

融合网络的QoS问题探讨

通信网络的融合需要更完善的服务质量（QoS）体系。引入基于IP多媒体子系统（IMS）框架的QoS资源控制架构是解决融合网络QoS问题的方法。基于IMS框架的QoS控制架构将业务、QoS保证、资源控制和计费结合起来，是融合网络，特别是当前固网运营商急需的体系架构，能解决固网运营商当前运营过程中面临的问题，使其可以开展更多有QoS保证的多媒体业务，如3D游戏等，有助于运营商从通信带宽提供服务商向通信业务运营商转型。     

QoS-aware computational method for IoT composite service

This paper integrated the quality of service (QoS) requirements of Internet of things (IoT) composite services, and put forward effective decomposition and optimization methods of the QoS metrics. The authors break down the complex QoS calculation model into four basic models, and each model is given a computational method. Combined with the QoS technology of the composite service, the authors adopt the algorithm to find the sub-optimal service with an acceptable cost under the QoS constraints. The proposed algorithm can quickly provide QoS computing services than other two algorithms for large-scale IoT compose services.     

移动云服务的自适应业务质量管理

The rapid growth of cloud computing and mobile Internet services has triggered the emergence of mobile cloud services. Among many challenges, QoS management is one of the crucial issues for mobile cloud services. However, existing works on QoS management for cloud computing can hardly fit well to the mobile environment. This paper presents a QoS management architecture and an adaptive management process that can predict, assess and ensure QoS of mobile cloud services. Furthermore, we propose an adaptive QoS management model based on Fuzzy Cognitive Maps (FCM), which suitably represents the causal relationships among QoS related properties and cloud service modes. We evaluate the proposed solution and demonstrate its effectiveness and benefits based on simulation work.     

多策略QoS感知的服务选择与排序模型

随着网络中具有相同功能、不同QoS服务的增多,在用户请求服务时,为了确保能找到满足用户功能与质量要求的服务,并对找到的可用候选服务集按一定的策略进行选优,提出了一种多策略QoS感知的服务选择与排序模型。在该模型中,综合考虑服务的性能与运营维护成本等属性,提出了一个扩展的服务QoS模型,在此基础上引入用户、运营商对服务满意度的计算方法,通过改变用户满意度与运营商满意度在排序选优过程中所占的不同比重,灵活设置服务选优策略,有效的解决了服务排序选优问题。搭建了服务选择与排序原型系统,并通过应用实例对上述模型进行了验证。     

基于Bootstrap技术的Web服务QoS值的置信区间估计和预测

目前对Web服务QoS（Quality of Service）的预测研究,通常预测QoS的静态值,很少预测QoS值的置信区间.本文借助非参数统计学的Bootstrap技术,提出估计Web服务QoS值置信区间的方法;然后利用与当前Web用户相似的其他Web用户调用待预测Web服务的QoS历史数据,预测当前Web用户调用待预测Web服务的QoS值的置信区间.本文估计了WSDream数据集1中每个用户调用每个Web服务的QoS值的置信区间,实验发现这些置信区间的上下限近似服从重尾分布.通过随机选择WSDream数据集1中60%到90%的用户和Web服务作为训练集,预测另外10%到40%的用户和Web服务的QoS值,实验结果表明预测的QoS置信区间与估计的QoS置信区间的平均覆盖率超过70%,最高达76%.在服务选择或服务推荐时给用户提供一个估计的或预测的QoS置信区间,可以更好地满足用户的个性化需求.     

基于测量目的的Web服务QoS监控框架

为了更好地度量和监测Web服务的服务质量，在充分考虑服务提供商、服务使用者个体及服务潜在消费者三方需要的基础上，建立一种基于测量目的的QoS度量体系。在此基础上分析现有的Web服务监测、控制机制，提出了一个基于测量目的的QoS监测、控制框架。     

Web service composition algorithm based on TOPSIS

Independent quality of service(QoS)registration center is difficult to monitor QoS with lots of requests in Internet environment with a large number of services and lots of service requests.It is able to reduce the load and decrease the failure rate by using multiple QoS registration centers to monitor QoS of some services with lots of requests.In addition,the heterogeneous QoS data close to user’s habitual expression and adapts to the environment with complexity and uncertainty.This paper introduces a novel Web service composition algorithm based on technique for order preference by similarity to an ideal solution(TOPSIS)(WSCA_TOPSIS)to solve the above difficulties for the first time.WSCA_TOPSIS can support multiple decision-makers and heterogeneous QoS data.It includes three main steps:normalizing decision matrix,evaluating alternatives synthetically and evaluating group alternatives synthetically.Other contributions of the paper include a novel algorithm of aggregating QoS and a set of experiments that demonstrate the benefits and effectiveness of our approach.Experimental results show that the proposed algorithm can better support Web service composition with heterogeneous QoS data and multiple decision-makers.     

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。     

互联网的服务质量控制和管理

文章介绍了互联网的业务管理模式、服务质量控制和管理体系结构,并对服务质量控制和管理的关键技术,如集成服务、区分服务、服务质量计费、服务质量测量等,进行了分析。     

基于结构化噪声矩阵补全的Web服务QoS预测

随着面向服务计算技术的快速发展,越来越多具有相同或相似功能的Web服务被部署在网络上。用户进行服务选择之前,通常需要根据历史调用信息对未使用过的服务QoS进行预测。由于历史调用信息收集过程缺乏有效的监督和约束机制,所采样的QoS信息往往容易受到结构化噪声污染,从而导致现有方法预测性能急剧下降。为了克服这个困难,通过将Web服务QoS预测问题建模为L2,1范数正则化矩阵补全问题,提出了一类基于结构化噪声矩阵补全的Web服务QoS预测方法。真实数据集上的实验结果表明,该方法不仅能精确地辨识出QoS采样矩阵中噪声行所在位置,而且能对缺失Web服务QoS进行有效预测。     

基于Web Services的QoS本体研究

QoS本体为描述不同系统的QoS参数提供了一种有效、可重用的模型,已经应用于Web Services选择、QoS监控和QoS参数调整等方面。通过比较和分析几种典型的QoS本体的特点,可以得出大多数QoS本体考虑如度量、协议和网络属性等概念,这些特征应用于Web Service发现,特别是Web Service选择,对进一步开发QoS本体、选择最优的服务质量有着重要意义。     

一种异构网络中基于聚集流的水平QoS映射方法

保证无线异构网络端到端QoS需求,同时兼容现有网络业务和未来需求,是下一代网络的一个研究热点。QoS映射是保证异构网络端到端QoS的有效方法。该文提出一种基于聚集流的QoS映射方法(QoS Mapping Technology based on Flow Aggregate, QMT-FA),该方法在现有物理网络上建立虚拟的流处理层,在流处理层,原网络中的QoS参数被映射执行器透明封装,映射执行器根据网络情况决定是原样转发还是解聚集。通过建立基于高维的聚集流映射空间,屏蔽了多级网络间映射累积误差影响终端网络QoS指标,保证了异构网络端到端QoS;基于聚集流的QoS映射方法具有较好的可扩展性和伸缩性,能应用于现有的各种异构网络系统和应用业务。最后,通过数值和仿真分析验证了该方法的有效性。     

Web service selection algorithm based on principal component analysis

Existing Web service selection approaches usually assume that preferences of users have been provided in a quantitative form by users. However, due to the subjectivity and vagueness of preferences, it may be impractical for users to specify quantitative and exact preferences. Moreover, due to that Quality of Service (QoS) attributes are often interrelated, existing Web service selection approaches which employ weighted summation of QoS attribute values to compute the overall QoS of Web services may produce inaccurate results, since they do not take correlations among QoS attributes into account. To resolve these problems, a Web service selection framework considering user’s preference priority is proposed, which incorporates a searching mechanism with QoS range setting to identify services satisfying the user’s QoS constraints. With the identified service candidates, based on the idea of Principal Component Analysis (PCA), an algorithm of Web service selection named PCA-WSS (Web Service Selection based on PCA) is proposed, which can eliminate the correlations among QoS attributes and compute the overall QoS of Web services accurately. After computing the overall QoS for each service, the algorithm ranks the Web service candidates based on their overall QoS and recommends services with top QoS values to users. Finally, the effectiveness and feasibility of our approach are validated by experiments, i.e. the selected Web service by our approach is given high average evaluation than other ones by users and the time cost of PCA-WSS algorithm is not affected acutely by the number of service candidates.     

Relative QoS optimization for multiparty online gaming in DiffServ networks

Real-time interactive multimedia multiparty communication is becoming a vital part of modern Internet services. As one of its applications, online gaming attracts a huge group of fans playing over the Internet. It has new requirements for relative QoS. This article gives a brief introduction to these new QoS requirements, and then presents an algorithm to satisfy these requirements in the differentiated services network for client-server-topology-based online gaming services. Our simulation results show that this algorithm can provide optimized relative QoS support for online gaming as an example of multiparty communications.     

基于双层分级的无线城域网资源分配方案

未来移动通信系统,诸如IEEE802.16旨在能够传送多种具有不同QoS要求的多媒体业务。为了保证业务的QoS,需合理设计调度器的结构和相应的调度算法。针对IEEE802.16宽带无线接入系统中的双层分级带宽分配体系结构,结合总调度器分配算法优点,采用了更适用于分类调度器且不同于参考文献的分配算法,旨在能够针对不同QoS等级的业务提供不同的调度方案,更好地满足用户的QoS要求。     

The complementary roles of RSVP and differentiated services in thefull-service QoS network

With the growth of the Internet and intranets, QoS technology that has been developed over a span of several years is quickly becoming more relevant. This article first defines QoS and introduces a taxonomy for QoS mechanisms. The evolution of several major QoS mechanisms is described with a special focus on RSVP and differentiated services. Special attention is paid to the role of the IETF in developing QoS mechanisms. We describe a QoS network that combines RSVP and differentiated services in a manner that realizes the benefits of each. We show that, in general, the adoption of increasingly sophisticated QoS mechanisms can enhance the ability of a network to offer high-quality service guarantees while simultaneously making efficient use of raw network resources. These mechanisms carry a cost in the form of increased overhead, which must be weighed against the benefits of the mechanism     

一种基于LTE业务特征的调度算法切换系统

针对LTE业务QoS特征多样化且应考虑业务付费等级的问题,提出了一种改进的比例公平调度算法.新算法引入不同业务的各QoS指标、付费等级作为参数,并根据各业务的具体QoS需求在各参数的不同加权配置下切换.仿真结果表明,新算法不但可以极大提高付费业务的各项QoS指标.还能让所有业务的QoS指标达到既定需求,更好地适应了LT...     

“巴黎地铁定价”方案在因特网QoS中的应用

文章介绍在因特网中引入“巴黎地铁定价”(PMP)方案,把网络分成价格不同的几个通道,利用价格机制来提高因特网QoS。该方案根据价格提供区分服务,避免了QoS技术给因特网带来的复杂性,是最简单的因特网QoS解决方案。