MC 引言：有限资源←→无限增长的需求 人的需求是永远无法满是的 Demand for Video and P2P Creates Pressure And the network just can't cope... Network Congestion Existing Infrastructure Internet TV HTTPVideo P2P (Hulu,NBC etc.)(YouTube etc.) Downloads (BitTorrent etc.) POOR User Experience Bandwidth Demand 11 ynh,cxh@ustc.edu.cn
{ynh, {ynh,cxh cxh}@ustc.edu.cn }@ustc.edu.cn 引言：有限资源无限增长的需求 人的需求是永远无法满足的 11
MC 专题的由来： 感知体验(perceptual experience)的重要性 Providing high-quality streaming services over a best effort and shared infrastructure such as the Internet is nontrivial. This is increasingly placing loads on network elements to deliver streaming content with high perceptual quality, including content delivery networks(CDNs),overlay networks,video on demand (VoD),and Internet television (IPTV)infrastructures.Network service providers need to infer,predict,and improve perceptual experience to ensure long-term success. Inferring Video QoE in Real Time Mainak Chatterjee,University of Central Florida IEEE Network January/February 2011 12 ynh,cxh@ustc.edu.cn
{ynh, {ynh,cxh cxh}@ustc.edu.cn }@ustc.edu.cn 专题的由来： 感知体验(perceptual experience)的重要性 Providing high-quality streaming services over a best effort and shared infrastructure such as the Internet is nontrivial. This is increasingly placing loads on network elements to deliver streaming content with high perceptual quality, including content delivery networks (CDNs), overlay networks, video on demand (VoD), and Internet television (IPTV) infrastructures. Network service providers need to infer, predict, and improve perceptual experience to ensure long-term success. 12 Inferring Video QoE in Real Time Mainak Chatterjee, University of Central Florida IEEE Network • January/February 2011
MC 专题的由来： 用户体验是根本 ◆衡量一个网络和业务品质的最根本标准在于用户的 体验质量 QoE,Quality of Experience ▣ITU-TSGl2的定义：“the overall acceptability of an application or service,as perceived subjectively by the end user" ◆用户对于网络的满意度 13 ynh,cxh @ustc.edu.cn
{ynh, {ynh,cxh cxh}@ustc.edu.cn }@ustc.edu.cn 专题的由来： 用户体验是根本 衡量一个网络和业务品质的最根本标准在于用户的 体验质量 QoE，Quality of Experience ITU-T SG12的定义：“the overall acceptability of an application or service, as perceived subjectively by the end user” 用户对于网络的满意度 13
KC专题内容 ◆QoS与QoE概述 ▣QoS与QoE的概念 口QoS与QoE的区别与联系 ◆话音质量评估 ▣音频的失真 ▣话音质量评估方法 ◆视频质量评估 ▣图像和视频的失真 ▣图像和视频的质量评估方法 ▣网络视频的质量评估 14 ynh,cxh@ustc.edu.cn
{ynh, {ynh,cxh cxh}@ustc.edu.cn }@ustc.edu.cn 专题内容 QoS与QoE概述 QoS与QoE的概念 QoS与QoE的区别与联系 话音质量评估 音频的失真 话音质量评估方法 视频质量评估 图像和视频的失真 图像和视频的质量评估方法 网络视频的质量评估 14
C QoS(Quality of Service)参数 ◆可用带宽 ▣网络的两个节点之间特定业务流的平均速率 ◆时延 ▣数据包在网络的两个节点之间传送的平均往返时间 ◆丢包率 ▣在网络传输过程中丢失报文的百分比 ◆时延抖动 ▣时延的变化 ◆误包率 口网络传输中报文出现错误的百分比。 15 ynh,cxh@ustc.edu.cn
{ynh, {ynh,cxh cxh}@ustc.edu.cn }@ustc.edu.cn QoS(Quality of Service)参数 可用带宽 网络的两个节点之间特定业务流的平均速率 时延 数据包在网络的两个节点之间传送的平均往返时间 丢包率 在网络传输过程中丢失报文的百分比 时延抖动 时延的变化 误包率 网络传输中报文出现错误的百分比。 15