Joint In-network Video Rate Adaptation and Measurement-Based Admission Control: Algorithm Design and Evaluation

The important new revenue opportunities that multimedia services offer to network and service providers come with important management challenges. For providers, it is important to control the video quality that is offered and perceived by the user, typically known as the quality of experience (QoE). Both admission control and scalable video coding techniques can control the QoE by blocking connections or adapting the video rate but influence each other’s performance. In this article, we propose an in-network video rate adaptation mechanism that enables a provider to define a policy on how the video rate adaptation should be performed to maximize the provider’s objective (e.g., a maximization of revenue or QoE). We discuss the need for a close interaction of the video rate adaptation algorithm with a measurement based admission control system, allowing to effectively orchestrate both algorithms and timely switch from video rate adaptation to the blocking of connections. We propose two different rate adaptation decision algorithms that calculate which videos need to be adapted: an optimal one in terms of the provider’s policy and a heuristic based on the utility of each connection. Through an extensive performance evaluation, we show the impact of both algorithms on the rate adaptation, network utilisation and the stability of the video rate adaptation. We show that both algorithms outperform other configurations with at least 10 %. Moreover, we show that the proposed heuristic is about 500 times faster than the optimal algorithm and experiences only a performance drop of approximately 2 %, given the investigated video delivery scenario.     

基于XDR数据分析的OTT视频服务感知质量评估方法

互联网电视(over the top,OTT)视频业务逐渐成为最流行的在线业务之一,然而网络视频往往由于网络质量差、服务平台过载等原因,出现播放失败、卡顿次数增加、缓冲时间过长等质量问题,导致用户感知质量(quality of experience,QoE)下降.因此,运营商需要精确评估和掌握用户在使用网络视频业务过程中的质量体验,以便提前发现质量问题,进一步开展网络和业务优化工作.为了解决该问题,提出一种基于用户呼叫/事务/会话记录数据(extend data record,XDR)的无参考网络视频质量评估方法.该方法从大量XDR数据中提取出与视频质量相关性高的少量信息,将大规模、低价值的XDR话单数据转化为高价值、小规模的视频质量特征信息,有利于后续人工智能算法的应用和视频业务质量评价,降低进一步数据挖掘的资源成本,提升机器学习的输入样本质量和QoE评价结果的准确性.实验表明:使用该方法提取后的数据进行QoE预测,得到的预测结果在准确性方面明显优于目前基于原始XDR数据的QoE机器学习评估方法.     

An autonomic architecture for optimizing QoE in multimedia access networks

The recent emergence of multimedia services, such as Broadcast TV and Video on Demand over traditional twisted pair access networks, has complicated the network management in order to guarantee a decent Quality of Experience (QoE) for each user. The huge amount of services and the wide variety of service specifics require a QoE management on a per-user and per-service basis. This complexity can be tackled through the design of an autonomic QoE management architecture. In this article, the Knowledge Plane is presented as an autonomic layer that optimizes the QoE in multimedia access networks from the service originator to the user. It autonomously detects network problems, e.g. a congested link, bit errors on a link, etc. and determines an appropriate corrective action, e.g. switching to a lower bit rate video, adding an appropriate number of FEC packets, etc. The generic Knowledge Plane architecture is discussed, incorporating the triple design goal of an autonomic, generic and scalable architecture. The viability of an implementation using neural networks is investigated, by comparing it with a reasoner based on analytical equations. Performance results are presented of both reasoners in terms of both QoS and QoE metrics.     

Multipoint-to-point communications for SHE surveillance with QoS and QoE management

The bandwidth-hunger applications of SHE (Smart Home Environment) can take advantage of the multipoint-to-point (MPP) connections to aggregate more bandwidth to gain user-perceived Quality of Experience (QoE) and network Quality of Service (QoS). The receiver-centric transport-layer R²CP (Radial Reception Control Protocol) was proposed to resolve the incapability of the MPP communication in conventional TCP and UDP. However, R²CP has no consideration to discriminate the importance in a packet payload which is critical to QoE and brings an issue for critical data packets that may be dropped in great risk of network congestion. In this paper, we thus present P-R²CP (Prioritized R²CP) to effectively decrease the loss ratio of critical data packets in MPP video streaming while the network is congested. P-R²CP is a cross-layer protocol that considers both the transport-layer issues and the media content’s properties in application-layer. Then, an example on MPP-UVS (MPP ubiquitous video surveillance) is presented as UVS is now a very important Internet application that requires QoS/QoE management to protect lives and assets especially in SHE. Our experiments are conducted on different kinds of surveillance videos over MPP links with different bandwidth and packet loss inserted. The experimental results demonstrate that, as the loss of critical packets is decreased by an order and much less critical data packets are dropped, P-R²CP can highly guard not only QoS but also QoE of SHE surveillance video streaming.     

一种视频质量监测系统的设计与实现

网络服务提供商希望能从用户的角度了解目前网络所提供的服务质量,而用户也希望获得定量的指标来评价当前网络服务质量。为此,以视频质量监测为研究对象,提出一种面向用户体验质量的网络监测系统。通过实验分析了网络传输过程中QoS参数对视频QoE的影响;提出一种将视频流转化为测试序列的视频丢包测量方法,该方法能低入侵、准确测量视频传输过程中的丢包情况;基于以上的研究成果,通过对MIB库的扩展和对MIB库轮询机制的研究,构建了面向QoE的视频服务监测系统,该监测系统结构简单、可行性强,实验表明可实时对网络中的视频服务质量进行监测。     

Java- and CORBA-based network management

Systems to manage distributed heterogeneous networks and services must often use off-the-shelf components and leverage legacy applications. Much of the telecommunications industry uses a network architecture based on CMIP (Common Management Information Protocol) to manage networks and services, while much of the Internet uses the SNMP (Simple Network Management Protocol). To provide distributed network management, the telecommunications industry must accommodate both, Nokia developed the Distributed Computing Platform prototype to support the creation, management, and invocation of distributed telecommunications services. Using CORBA as a base, DCP handles network management by adding managed-object models and protocols. It provides mechanisms that allow communication between CMIP-based objects and a gateway for SNMP-based systems. The prototype also allows users to access network information via Web browsers, CGI gateways, and Java or HTTP daemons. The Nokia engineers also discuss the lessons they learned about Java and CORBA integration     

Merging social computing with content: a proposal of a new film platform,Avids

ABSTRACT

Film consumers are continuously online and active in various social platforms. This phenomenon has led over-the-top (OTT) providers – empowered by social computing technologies – to establish a social media presence and incorporate elements drawn from social media into their services. However, little is known about existing OTT interfaces and their key social features. This study sought to provide a structured categorisation of the most salient social media features of the best-known applications in the OTT video business. In addition, a new social content network model, Avids, was proposed to connect individuals socially through films. Avids reaches beyond more fixed, functionality-based approaches applied in the development of OTT video sites and focuses on components related to sociality. This approach ensures a unified system in which the overall social media setting is embedded in every functional area of the platform’s architecture, thereby allowing applications to trigger and support social behaviours absent from traditional OTT providers. A purpose-built international online survey was administered to 479 film lovers to assess how Avids’ main features compare with traditional OTT video providers. The questionnaire was based on the technology acceptance model. The results confirm the critical role of sociality in film viewing-related activities.     

基于MPC的音视频同步码率自适应测试

随着信息化的发展,音视频流媒体技术应用面越来越广,为了使得音视频流媒体技术尤其是在直播方面拥有更好的性能,得到更多用户的好评,采用在原本HTTP的动态自适应流标准的视频流媒体架构下引入MPC控制算法并将MPC模型预测控制与码率自适应算法相结合的方法,进行对AAC优化、确定预测模型、测试音视频同步的影响因素以及PSNR-Y分量、测试切片时长与跳帧时延,计算最终的QoE用户评价指标来进一步检测音视频流媒体技术的优劣。经实验仿真测试可知,相比前人的相关算法,在不同直播场景下以及不同网络环境下均有更加良好的QoE值,平均QoE用户评价指标明显更高,为1237.2826。综上分析可知,MPC的音视频同步码率自适应算法各项性能最好。     

End-to-End Resource Management for Federated Delivery of Multimedia Services

Recently, the Internet has become a popular platform for the delivery of multimedia content. Currently, multimedia services are either offered by Over-the-top (OTT) providers or by access ISPs over a managed IP network. As OTT providers offer their content across the best-effort Internet, they cannot offer any Quality of Service (QoS) guarantees to their users. On the other hand, users of managed multimedia services are limited to the relatively small selection of content offered by their own ISP. This article presents a framework that combines the advantages of both existing approaches, by dynamically setting up federations between the stakeholders involved in the content delivery process. Specifically, the framework provides an automated mechanism to set up end-to-end federations for QoS-aware delivery of multimedia content across the Internet. QoS contracts are automatically negotiated between the content provider, its customers, and the intermediary network domains. Additionally, a federated resource reservation algorithm is presented, which allows the framework to identify the optimal set of stakeholders and resources to include within a federation. Its goal is to minimize delivery costs for the content provider, while satisfying customer QoS requirements. Moreover, the presented framework allows intermediary storage sites to be included in these federations, supporting on-the-fly deployment of content caches along the delivery paths. The algorithm was thoroughly evaluated in order to validate our approach and assess the merits of including intermediary storage sites. The results clearly show the benefits of our method, with delivery cost reductions of up to 80 % in the evaluated scenario.     

Parallel video streaming optimizing network throughput

In the Internet, video streaming services, in which users can enjoy videos at home, are becoming popular. Video streaming with high definition TV (HDTV) or ultra high definition video (UHDV) quality will be also provided and widely demanded in the future. However, the transmission bit-rate of high-quality video streaming is quite large, so generated traffic flows will cause link congestion. In the Internet, routes that packets take are determined using static link weights, so the network productivity, i.e., the maximum achievable throughout by the network, is determined by the capacity of a bottleneck link with the maximum utilization, although utilizations of many links remain low level. Therefore, when providing streaming services of rich content, i.e., videos with HDTV or UHDV quality, it is important to flatten the link utilization, i.e., reduce the maximum link utilization. We propose that ISPs use multiple servers to deliver rich content to balance the link utilization and propose server allocation and server selection methods for parallel delivery. We evaluate the effect of parallel delivery using 23 actual commercial ISP networks.     

Analysis of YouTube’s traffic adaptation to dynamic environments

The popular Internet service, YouTube, has adopted by default the HyperText Markup Language version 5 (HTML5). With this adoption, YouTube has moved to Dynamic Adaptive Streaming over HTTP (DASH) as Adaptive BitRate (ABR) video streaming technology. Furthermore, rate adaptation in DASH is solely receiver-driven. This issue motivates this work to make a deep analysis of YouTube’s particular DASH implementation. Firstly, this article provides a state of the art about DASH and adaptive streaming technology, and also YouTube traffic characterization related work. Secondly, this paper describes a new methodology and test-bed for YouTube’s DASH implementation traffic characterization and performance measurement. This methodology and test-bed do not make use of proxies and, moreover, they are able to cope with YouTube traffic redirections. Finally, a set of experimental results are provided, involving a dataset of 310 YouTube’s videos. The depicted results show a YouTube’s traffic pattern characterization and a discussion about allowed download bandwidth, YouTube’s consumed bitrate and quality of the video. Moreover, the obtained results are cross-validated with the analysis of HTTP requests performed by YouTube’s video player. The outcomes of this article are applicable in the field of Quality of Service (QoS) and Quality of Experience (QoE) management. This is valuable information for Internet Service Providers (ISPs), because QoS management based on assured download bandwidth can be used in order to provide a target end-user’s QoE when YouTube service is being consumed.     

The CASPER user-centric approach for advanced service provisioning in mobile networks

This paper presents an overview of the project CASPER,¹ a 4-year Marie Curie Research and Innovation Staff Exchange (RISE) project running between 2016 and 2020, describing its objectives, approach, architecture, tools and key achievements. CASPER combines academic and industrial forces towards leveraging the expected benefits of Quality of Experience (QoE) exploitation in future networks. In order to achieve that, a QoE orchestrator has been proposed which implements the basic functionalities of QoE monitoring, estimation and management. With means of simulation and testbed emulation, CASPER has managed to develop a proprietary SDN Controller, which implements QoE-based traffic rerouting for the challenging scenario of HTTP adaptive video streaming, leading to more stable and higher QoE scores compared to a state-of-the-art SDN Controller implementation.     

IP网络中视频流QoE评价模型

网络视频业务的兴起使网络运营商和服务提供商更加关注视频的用户体验（QoE）,然而视频用户体验（QoE）值由于其主观性且评价过程复杂,难以在视频流传输中实时获取。通过实验分析了视频传输过程中服务质量（QoS）参数变化对视频QoE的影响,建立了客观、可测量的QoS参数与视频QoE之间映射模型,用可量化的QoS参数来评定视频QoE受网络性能的影响程度,以评估网络视频质量,该模型形式简单,能够实时监测视频质量。实验结果表明,该模型的评价结果能较好反映视频QoE。     

命名数据网络中的视频传输研究综述

互联网目前已经发展为一个由实时视频和视频点播等内容分发服务主导的网络.传统IP网络对于视频分发类任务的支持存在组播的部署复杂且开销大,不能有效利用多路径获取内容、对移动性的支持差和难以同时满足可靠性以及低延时需求等问题.命名数据网络(named data networking,NDN)作为新型的下一代互联网体系结构,支持网络内缓存和多路径传输,而且由消费者驱动的传输模式使其天然地支持消费者端移动性.以上特点使NDN具有高效传输视频内容的潜力.首先介绍了视频传输和NDN的基础背景,然后阐述了一些利用NDN中优势实现视频传输的设计方案.通过对已有方案的总结与比较,最后指出了在NDN中传输视频所面临的挑战.     

基于联邦共识机制的多视频流带宽分配策略

针对瓶颈链路中视频带宽分配不均导致的用户QoE不公平以及带宽利用率低的问题,提出了一种基于联邦深度强化学习的分布式视频流公平调度策略。该策略能够根据客户端网络状态和视频QoE等级动态生成带宽分配权重因子,服务器端的拥塞控制算法则根据带宽分配权重因子为瓶颈链路中的每个视频流分配带宽,以保障瓶颈链路中视频流的公平传输。每个视频终端都运行一个带宽分配agent,且多个agent以联邦学习的方式周期性地训练,以便代理模型能够快速收敛。带宽分配agent通过共识机制同步联邦训练参数,实现了在异步播放请求条件下带宽分配agent模型参数的分布式聚合,并确保了agent模型参数的安全共享。实验结果表明,与最新方案相比,提出策略在QoE公平性和整体QoE效率方面分别提高了10%和7%,这表明提出策略在解决视频流带宽分配不均问题和提升用户体验方面具有潜力和有效性。     

Direct push–pull or assisted push–pull? Toward optimal video content delivery using shared storage-based cloud CDN (SS-CCDN)

Video content delivery networks face many challenges such as scalability, quality of service and flexibility. Video suppliers address them through CDN. Cloud computing and Video content Delivery as a Service (VDaaS) plays a key role in improving the content delivery standard and makes the work of content providers, easier. By hosting video contents in the cloud, the content delivery costs are minimized and the overall content delivery performance enhanced by optimization of cloud CDN. Cost optimization of the cloud-based content delivery network requires a focus on delay or throughput, the overall performance and content delivery. The content placement and content access, the QoS and the QoE in CDN can be improved by enhancing the video content delivery performance. In this paper, a unique model for video content delivery, cloud-based is developed, titled as shared storage-based cloud CDN (SS-CCDN) to achieve the objective. This design optimizes through algorithms, the effective placement of video data and dynamic update of video data. For analysis, GA, PSO, and ACO algorithms are used. The proposed model uses direct and assisted push–pull content delivery schemes for cost-efficient content delivery. The low-cost VDaaS model reduces the storage cost, keeps the latency and the traffic cost. Experimental results validate that this model, with regard to storage, traffic, and latency generate higher performance with lower price and satisfy the QoS and QoE aspects in content delivery.

     

HTTP移动流媒体QoE管理综述

随着移动通信网络和技术的快速发展,多媒体信息的大量涌现,人们对多媒体信息服务的要求也越来越高。基于HTTP协议的移动流媒体由于拥有广泛运营基础的Web服务器网络环境,部署简单,适用范围广泛等优点成为研究的热点。简要介绍了HTTP移动流媒体的相关特点,重点分析了影响HTTP移动流媒体用户体验质量的各层因素,归纳总结了评价方法和现有的工具,并对 HTTP 移动流媒体相应的优化进行了介绍,最后对HTTP移动流媒体QoE管理进行了总结和展望。     

QoE management for video conferencing applications

We introduce a framework for managing the QoE of videos coded with the H.264 codec and transmitted by video conferencing applications through limited bandwidth networks. We focus our study on the medium-motion videos with QCIF, CIF, and VGA resolutions, the most pervasive video formats used by video conferencing applications across the Internet and cellular telephony systems. Using subjective tests for measuring the level of video quality perceived by end users, we expose the relation between the main influential video parameters and the quality experienced by end users. Furthermore, after investigating the effect of different frame rates and compression levels on video streaming bit rate, and consequently on QoE, we propose a QoE control mechanism for limited-bandwidth situations. A congestion control technique is also introduced in this paper and used in simulations for verifying the efficiency of the proposed QoE management algorithm and to implement this algorithm for practical applications.     

利用HTTP协议进行移动视频分发的应用研究

在过去的十年中,基于互联网的视频分发服务已经成为现代日常生活的一部分。3G蜂窝网覆盖范围的扩展以及大量高性能的移动设备的出现,加剧了对于大数据量可扩展移动视频分发业务的需求。采用第三屏幕作为视频主屏幕的方式,解决移动数据分发生态系统中的效率低下问题以及移动数据分发基础设施的可扩展问题已成为研究热点之一。文中在研究当前移动内容分发系统基本策略的基础上,提出了一种基于HTTP协议的改进的移动视频分发方法,有效地提高了移动视频分发系统的服务质量和可扩展性。