软件定义多媒体组播系统与传输策略研究

发布时间：2018-05-17 12:58

本文选题：软件定义网络 + 可伸缩视频编码　；参考：《中国科学技术大学》2017年博士论文

【摘要】：近年来随着网络与多媒体技术的进步,诸如互联网电视、视频会议、视频点播、网络视频监控、虚拟现实等多媒体应用越来越深入到人们的生产和生活中。随之而来的是网络中IP流量的急速增长,而快速增长的网络资源消耗,可引发网络拥塞、传输时延变大等问题,最终会降低多媒体业务的服务质量,导致用户体验变差,因此需要寻求新的机制、架构和算法对多媒体传输业务进行优化。网络承载的业务不断丰富,当前互联网出现了诸如体系臃肿、服务质量保障缺失等方面的问题,因此学术与产业界正在探索建立新的网络体系架构。软件定义网络(Software Defined Networking,SDN)近年来被提出,因其支持服务可编程、网络可控等优势被业界认为是下一代互联网的发展方向。利用多媒体编解码的先进技术、网络优化理论、在线网络测量以及组播技术等手段,研究在软件定义网络中的多媒体传输机制、架构和算法,对于解决多媒体传输存在的问题具有重要意义。为了保证网络多媒体的服务质量,优化网络资源的利用率,本文研究了在软件定义网络环境下的多媒体组播传输控制与优化问题,主要研究工作概括如下:1)软件定义可伸缩视频组播系统架构的研究。利用SDN提供的网络可控、可编程的特点,针对可伸缩视频,本文研究如何构建在软件定义网络中的多媒体业务组播服务系统。为了使网络转发节点支持对视频内容的感知、实现完全可控的组播,本文设计了管理子系统,同时定义了视频服务系统中的功能实体并设计了组成功能实体的各个模块。为了满足系统对服务质量(Quality of Service,QoS)的支持,本文提出了在软件定义视频组播系统中链路带宽和网络时延的测量方法。针对系统在实际网络中部署时存在的域间和跨ISP服务问题,本文提出了支持大规模网络的域间与多ISP部署服务解决方案。在提出架构的基础上,我们搭建了软件定义可伸缩视频组播的原型系统,进行了相关实验以评估系统的性能。实验表明,提出的架构能够实现可伸缩视频在软件定义网络下的组播传输业务,能够达到优化网络资源利用的目的。2)软件定义网络中可伸缩视频自适应组播传输策略的研究。本文提出的软件定义可伸缩视频组播系统架构中,管理服务器的策略模块支持路由计算、组播树构建、视频传输控制等算法的定制,可以根据不同的场景、应用和需求部署不同的策略。本文提出了在软件定义网络中具有可用带宽和时延约束的组播路由算法,根据SDN控制器中的网络拓扑和链路状态等信息,构建具有QoS约束的最小代价视频组播树;同时本文提出了基于等效带宽估计的组播自适应调节控制策略,可伸缩视频在SDN网络传输过程中,系统可以依据网络状态信息检测到网络链路拥塞,依据相应层数选择算法在网络内部动态地调节可伸缩视频的传输层数,保证用户的观看体验。我们在原型系统中进行了相关实验,实验结果表明提出的算法和策略能够有效避免网络链路拥塞,显著提高视频业务的服务质量。3)软件定义网络中基于分层组播的视频会议系统研究。本文在软件定义网络中,基于可伸缩视频编解码技术和网络组播技术部署视频会议服务。在基于MCU的视频会议系统中,由于集中式的MCU具有很高的负载,极有可能成为系统的瓶颈,难以确保较高的QoS;而采用P2P技术部署的视频会议系统,成员上行网络带宽资源的限制也可能导致服务的中断。本文提出的系统中,集中式会议管理服务器只负责管理会议,而不接收和处理来自会议成员的媒体数据。会议管理服务器通过网络控制器提供的接口获取网络拓扑信息、网络可用带宽和路径时延等状态信息,从而为SVC视频流建立具有QoS约束的组播树,并在服务过程中采用基于等效带宽估计的可伸缩视频自适应组播传输策略,动态地调节网络中传输的视频流。实验结果表明,所提出的系统不仅可以提供灵活可控的视频会议组播传输,而且可以减少网络带宽的使用,保证视频会议的服务质量。
[Abstract]:In recent years, with the progress of network and multimedia technology, such as Internet television, video conferencing, video on demand, network video surveillance, virtual reality and so on, multimedia applications are becoming more and more deep into people's production and life. The rapid growth of IP traffic in the network is followed, and the rapid growth of network resources can lead to network support. Problems such as plug and transmission delay will eventually reduce the service quality of multimedia services and lead to the deterioration of user experience. Therefore, we need to seek new mechanisms, architecture and algorithms to optimize the multimedia transmission service. The network is rich in service, and the current Internet has appeared in such aspects as overstaffed system and lack of quality of service. Therefore, the academic and industrial circles are exploring the establishment of a new network architecture. Software Defined Networking (SDN) has been proposed in recent years, because its support service is programmable, and the advantages of network controllability are considered to be the development side of the next generation Internet. The advanced technology of multimedia codec is used to optimize network. Theory, online network measurement and multicast technology are used to study multimedia transmission mechanism, architecture and algorithm in software defined network. It is of great significance to solve the problem of multimedia transmission. In order to guarantee the quality of network multimedia service and optimize the utilization of network resources, this paper studies the definition of network loop in software. The main work of multimedia multicast transmission control and optimization is summarized as follows: 1) the research of software definition scalable video multicast architecture. Using the network controllable and programmable features provided by SDN, this paper studies how to construct multimedia service multicast service system in the software definition network. In order to enable the network forwarding node to support the perception of video content and realize the completely controllable multicast, this paper designs a management subsystem, defines the functional entities in the video service system and designs the modules that make up the functional entities. In order to satisfy the support of Quality of Service (QoS), this paper puts forward in this paper The software defines the measurement method of link bandwidth and network delay in video multicast system. Aiming at the problem of inter domain and cross ISP service in the actual network deployment, this paper proposes a solution for inter domain and multi ISP deployment services to support large-scale networks. The prototype system of frequency multicast has carried out some experiments to evaluate the performance of the system. The experiment shows that the proposed architecture can achieve multicast transmission service in the software defined network, and can achieve the purpose of optimizing the use of network resources.2) the research of extensible video Adaptive multicast transmission strategy in the software definition network. In the framework of software definition scalable video multicast system, the policy module of management server supports routing computing, multicast tree construction, video transmission control and other algorithms. It can deploy different strategies according to different scenarios, applications and requirements. This paper proposes that the bandwidth and delay constraints are available in the software definition network. The multicast routing algorithm is based on the network topology and link state in the SDN controller to construct the minimum cost video multicast tree with QoS constraints. At the same time, this paper proposes a multicast adaptive control strategy based on the equivalent bandwidth estimation. In the SDN network transmission process, the scalable video can be based on the network state information detection. The network link congestion is measured, and the number of scalable video transmission layers is dynamically adjusted within the network according to the corresponding layer number selection algorithm, and the user's viewing experience is guaranteed. We have carried out the related experiments in the prototype system. The experimental results show that the proposed algorithm and strategy can effectively avoid network link congestion and significantly improve the service of video service. .3 in software definition network based on layered multicast video conferencing system. In this paper, video conference services are deployed based on scalable video codec technology and network multicast technology in software defined networks. In MCU based video conferencing systems, because centralized MCU has a high load, it is very likely to become a system A bottleneck is difficult to ensure a higher QoS; and a video conferencing system deployed by P2P technology may also lead to a disruption in service. In this paper, a centralized conference management server is responsible for managing meetings only without receiving and handling media data from members of the conference. Conference management services By using the interface provided by the network controller, the network topology information is obtained, the network available bandwidth and path delay and other state information are used to establish a multicast tree with QoS constraints for the SVC video stream, and the scalable video Adaptive multicast transmission strategy based on the equivalent bandwidth estimation is adopted in the service process, which dynamically regulates the transmission in the network. The experimental results show that the proposed system can not only provide flexible and controllable multicast transmission of video conferencing, but also reduce the use of network bandwidth and ensure the quality of video conferencing service.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN919.8

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