基于融合CDN构建未来智能内容管道

详细探讨了传统CDN向融合CDN的演进方案、融合CDN构建智能内容管道的方法及在管道中的作用.为了更好地支撑业务发展,融合CDN需要与承载网络相互渗透,具备网络感知、业务感知、用户感知三大能力.为了保障移动业务的更好体验,提出CDN的网络位置应该下移到无线网络中,并根据无线网络的特性进行适配和优化.     

海量、高清、多屏视频驱动下的新一代CDN

内容分发网络（Content Delivery Network，CDN）并不是新事物，但它随着互联网应用的发展而不断演进。不管CDN如何演进，它部是以解决IP网络带宽不足，提高业务OoS为目的。     

CDN技术演进探讨

一、CDN现状和面临的挑战 CDN（Content Delivery Network）即内容分发网络,定位在互联网上建立一张面向业务的流量或内容的分发网络,解决内容传输的速度和稳定性问题。CDN能够按实时网络流量、网络段落、负载状况、到用户的距离和响应时间等信息,将用户的请求重新引向离用户最近的服务中心,使用户就近取得所需内容,     

基于CDN内容分发的研究与应用

内容分发网络（CDN）技术是近年来在美国首先兴起并迅速发展起来的一种解决互联网性能不佳问题的有效手段。CDN系统能够实时地根据网络流量和个节点的联接、负载状况以及到用户的距离和响应时间等综合信息将用户的请求重新导向离用户最近的服务节点上以并提高互联网性能。简要讲述了CDN网络原理,从基于内容访问度和负载均衡的角度出发研究将信息资源推向网络边缘的内容分发策略问题,并提出主要分发策略的思想和算法。最后讲述了CDN在互联网中的实际应用。     

内容分发网络发展与技术综述

CDN的出现解决了长期影响互联网传输过程中出现的网络拥塞、访问延迟、服务器负载过重等问题.本文内容围绕CDN的发展历程展望其未来发展前景,并结合CDN的框架结构详细阐述了实现CDN的关键技术及发展方向.     

内容分发网络的研究

随着宽带网络和宽带流媒体应用的兴起,内容分发网络（CDN）作为一种提高网络传输内容,特别是流媒体内容传输的服务质量、节省骨干网络带宽的技术,在国内外得到越来越广泛的应用。CDN是一个建立在不同区域的节点服务器组成的虚拟网络,CDN可以实现把互联网上的内容高效、稳定地发送到离网民最近的地方。这里总结介绍CDN出现的原因,CDN的技术基础及其分层模型,流媒体CDN的性能指标。     

全球CDN业务发展现状与趋势

内容分发网络（CDN）技术能将高速网络的性能和成熟的内容处理相结合，扩展基础网络体系的能力，改善用户访问网络的体验。通过介绍全球CDN业务发展情况，分析CDN市场的发展和投资前景，预测CDN的未来发展趋势。     

全面解析IPTV中CDN技术

CDN的核心是边缘访问和透明访问目前在IPTV网上CDN的边缘访问是提高IP承载网QoS的有效途径,很多运营商在宽带网上都部署了CDN/MDN,为IPTV网络的建设奠定了良好的基础。CDN网络的出现,使互联网资源得到了最大限度的利用。将大大推动国内IPTV业务的发展。     

互联网内容分发网技术和标准化现状

经过十几年的发展,内容分发网（CDN）已经逐渐演变为互联网重要的基础设施,为确保全球互联网服务质量发挥了重要作用。相比之下,我国CDN技术水平和服务能力还有待提高,产业发展仍然面临一些不利因素。为破解我国CDN产业的这些问题,开展CDN的标准化,规范市场,减少重复投资,为产品管理奠定科学基础,为产品质量提供检验规范,是十分必要的。     

三大力量驱动CDN开启加速度发展模式

互联网流量的爆发式增长将对流量调度业务产生大量需求,尤其是来自于视频、移动互联网及云计算的高速增长将驱动CDN市场快速发展。作为缓解网络拥塞、提高互联网业务响应速度、改善用户业务体验的重要手段,CDN（Content Delivery Network,内容分发网络）近年来在我国呈现出了高速增长的态势,根据工信部电信研究院的数据,2013年我国专业CDN市场规模同比增长50％,总量达到22亿元人民币。     

QoE/QoS driven simulated annealing-based genetic algorithm for Web services selection

In order to improve the efficiency and effect of Web service selection, an algorithm named quality of experience (QoE)/quality of service (QoS) driven simulated annealing-based genetic algorithm (QQDSGA) is given to achieve Web services selection efficiently with excellent QoE. QQDSGA includes two parts: QoE/QoS driven composite Web services evaluation model and simulated annealing-based (SA-based) genetic algorithm for Web services selection. Simulations show that when used in Web service selection, QQDSGA is better than genetic algorithm (GA) and SA in efficiency and is more satisfied in effect than no customer feedback.     

移动互联网助推移动视讯发展

随着移动互联网的飞速发展,移动网络速度不断提升,智能终端成本持续下降,移动互联网为多媒体视讯发展带来新的增长契机——移动视讯。结合移动应用、位置定位、传感器件等智能终端技术,移动视讯在监控、会话、会议、消息等方面得到广泛应用。同时,移动互联网催生了包括微视频、富媒体广告在内的多种新颖移动视讯形式。移动互联网在提升移动视讯服务质量的同时,在应用的深度和广度上也极大程度地推动移动视讯的发展。但是受限于移动智能终端的特点和无线数据信道的稳定性差,移动视讯也存在诸多问题。本文首先阐述移动视讯技术需求和移动互联网特点优势,进而介绍移动互联网在移动视讯中典型应用,最后分析移动视讯存在的问题。     

基于使用者反馈的用户体验质量管理构架

Recently, Quality of Experience (QoE) has been introduced as a subjective measure of a user’s experience of communication services. QoE was expected to take the place of traditional Quality of Ser-vice (QoS) measure in that QoE may express a direct and accurate user experience. In this paper, we propose a QoE management scheme which is based on a user’s simple feedback. We explain the proposed QoE management steps and the dominant reason extraction algorithm to determine the quality-falling instance. We also present a QoE prediction method that will provide an optimal quality management scheme in communication services. Experiments on mul-timedia streaming service prove the efficiency of the dominant factor extraction algorithm, and the experiment using the QoE prediction method present a very high accuracy. The QoE management scheme proposed in this paper can be generally adapted to any communication services, to increase the efficiency and effectiveness of quality man-agement systems.     

IPTV媒体分发技术之一--代理缓存

媒体分发技术在保证IPTV业务的服务质量上具有相当关键的作用.CDN(内容分发网络)技术在Web业务上得到了较为广泛的应用,但与传统的Web业务不同,IPTV需要分发的内容是数据量相当大的视频数据,采用传统的CDN技术不能完全满足IPTV业务的需要.本文介绍应用于IPTV视频流分发的代理缓存技术.     

一种基于QoS的QoE到SLA映射方法

该文提出一种算法IQoE2QoS(Improved QoE to QoS),采用模糊理论的方法计算QoE到QoS的映射。该算法有3重目标:从大量的经验数据中通过计算互信息量方式总结被统计指标之间的关联程度。在大量经验数据的基础上通过多指标模糊判定理论将用户感知映射到应用层用户QoS参数。考虑了用户的QoE和QoS的双向映射,并且阐述了得到的QoE如何自然映射到SLA(Service Level Agreement)。通过仿真表明,IQoE2QoS算法对用户体验的分类准确度是线性回归算法的2到3倍。     

QoE Model Based Optimization for Streaming Media Service Considering Equipment and Environment Factors

With the development of smart phones, one of the hot research topics for wireless personal communication technologies has begun to transit from reaching higher communication capabilities to better Quality of Experiences (QoE). However, for streaming services, such as online music or online video, which is one of the mainstream services in the future wireless network, there is still no breakthrough optimization beyond the Quality of Service (QoS) hence the optimization results are not satisfactory. Based on our study, this problem could be relieved by altering the criterion of wireless resource allocation from enhancing users?? QoS to enhancing their QoE, which specifically means that the scope of the research is extended from the so-called last mile between the network and the user equipment to the last few inches between the user equipment and the user himself. Unfortunately, it seems that all current QoE researches are still not jointly considering the users?? environment and user equipments?? performance, both of which are paramount factors of the last inches that will influence users?? QoE directly and profoundly. Hence, in this paper, we propose a QoE model involving the environment and equipment factors, and then we use this model to guide the wireless resource allocation. Simulation results show that this resource allocation method will increase the effectiveness of network resource utilization as well as improve the average of satisfaction of users.     

Enhanced calculation of necessary QoS for user satisfaction with a QoS mapping matrix

The final goal of quality of service(QoS) guarantees is to assure high quality of experience(QoE) for users.We cannot control QoE,but it is feasible to use QoS control schemes at lower levels to keep QoE high.We need to know the necessary QoS parameters values which need the minimum cost but could satisfy required QoE.An enhanced method is proposed to get the necessary QoS parameters which cost minimum but could satisfy required QoE well.It abstracts the problem of obtain necessary QoS parameters to be how to get the solution of linear regression equations considering cost coefficient.The method establishes equations utilizing principal component analysis and multiple regression analysis based on normalized data.This paper defines the cost of necessary QoS and introduces the calculation of minimum cost necessary QoS parameter by inverse or generalized inverse matrix operations.The numerical example proves the normalization to be effective and the calculated values are feasible.     

Discrete quality assessment in IPTV content distribution networks

Maintaining the quality of videos in resource-intensive IPTV services is challenging due to the nature of packet-based content distribution networks (CDN). Network impairments are unpredictable and highly detrimental to the quality of video content. Quality of the end user experience (QoE) has become a critical service differentiator. An efficient real-time quality assessment service in distribution networks is the foundation of service quality monitoring and management. The perceptual impact of individual impairments varies significantly and is influenced by complex impact factors. Without differentiating the impact of quality violation events to the user experience, existing assessment methodologies based on network QoS such as packet loss rate cannot provide adequate supports for the IPTV service assessment. A discrete perceptual impact evaluation quality assessment (DEQA) framework is introduced in this paper. The proposed framework enables a real-time, non-intrusive assessment service by efficiently recognising and assessing individual quality violation events in the IPTV distribution network. The discrete perceptual impacts to a media session are aggregated for the overall user level quality evaluation. With its deployment scheme the DEQA framework also facilitates efficient network diagnosis and QoE management. To realise the key assessment function of the framework and investigate the proposed advanced packet inspection mechanism, we also introduce the dedicated evaluation testbed—the LA2 system. A subjective experiment with data analysis is also presented to demonstrate the development of perceptual impact assessment functions using analytical inference, the tools of the LA2 system, subjective user tests and statistical modelling.     

Subjective QoE analysis of VoIP applications in?a?wireless?campus?environment

The quality perceived by the user, a concept known as Quality of user Experience (QoE), is gaining momentum. Together with the efforts of providing appropriate architectures able to deliver the expected level of Quality of Service (QoS), users’ perception of the level of quality could play a key role in making a VoIP multimedia application to succeed or to fail. QoE can be measured from different approaches; subjective ones are based on polls while objective ones are mainly based on QoS network performance parameters. Although a subjective evaluation could be costly and time consuming, it gives the most accurate results. Moreover, wireless environments incorporate new challenges in terms of QoS and QoE because of inherent wireless communication characteristics. In this way, our contribution is twofold. First, we carry out a subjective QoE assessment for VoIP applications in a real wireless environment. Skype, Gizmo5, ooVoo, and Damaka are the selected VoIP applications under study. Next, we contrast QoE results with QoS evaluation from the captured video calls made during the poll. Results show that there is no precise match on both assessments, because of QoE parameters that cannot be inferred from QoS analysis, because of the different effect of some QoS parameters which prevail, or even because of the popularity of the VoIP application.     

电信运营商互联网视频业务集约运营建设方案探讨

对电信运营商互联网视频业务集约运营的建设方案进行了探讨,从业务发展模式、CDN建设方案、网络承载方案、服务质量保障方案等方面进行了研究,对电信运营商的视频业务运营和网络建设具有借鉴意义。