LBAS: An effective pricing mechanism towards video migration in cloud-assisted VoD system

Migrating video instances to cloud to form a cloud-assisted VoD system is an efficient way to solve the problem of increasing costs in the traditional VoD system. In this paper, we focus on further decreasing the costs in this system. We propose a pricing mechanism named LBAS to allocate video instances from VoD provider’s local servers to cloud platforms. First, a pricing algorithm which conforms to the principle of market is presented to determine the price of each video instance. Then, an auction algorithm which is based on low bid and replaceable instances is proposed to determine the allocation and payment of video instances. At last, in order to avoid the collusion among bidders in low-bid auction, the AEM algorithm is improved. The simulation results demonstrate that the proposed mechanism makes the VoD provider decrease 10% of the costs compared with the VMC strategy.     

Blocking Probability Based Hierarchical Storage Design in VoD Systems

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Theatre in the Sky: a ubiquitous broadband multimedia‐on‐demand service over a novel constellation composed of quasi‐geostationary satellites

To meet an ever‐growing demand for wideband multimedia services and electronic connectivity across the world, development of ubiquitous broadband multimedia systems is gaining a tremendous interest at both commercial and academic levels. Satellite networks will play an indispensable role in the deployment of such systems. A significant number of satellite communication constellations have been thus proposed using Geostationary (GEO), Medium Earth Orbit (MEO), or Low Earth Orbit (LEO) satellites. These constellations, however, either require a potential number of satellites or are unable to provide data transmission with high elevation angles. This paper proposes a new satellite constellation composed of Quasi‐GeoStationary Orbit (Quasi‐GSO) satellites. The main advantage of the constellation is in its ability to provide global coverage with a significantly small number of satellites while, at the same time, maintaining high elevation angles. Based on a combination of this Quasi‐GSO satellites constellation and terrestrial networks, the paper proposes also an architecture for building a global, large‐scale, and efficient Video‐on‐Demand (VoD) system. The entire architecture is referred to as a ‘Theatre in the Sky’. Copyright © 2006 John Wiley & Sons, Ltd.     

IP家庭网络的服务质量架构研究

经过对IP网络和家庭网络服务体系的客观分析,提出了基于策略的IP家庭网络QoS保证架构.它融合了数据平面、控制平面和管理平面,可以与现有的IPQoS体系无缝连接,支持高质量的语音和视频服务.该结构对其他设备的依赖程度低,适应异构、复杂的家庭网络环境.通过在863项目中的应用,验证了该系统架构对IPTV、VoD及VoIP等多媒体业务的支持.     

一个视频点播系统的设计与实现

介绍了一种利用有线数字电视广播信道和支持IP交互信道的视频点播系统,广播信道用来传输点播的节目,交互信道传输机顶盒和前端服务器的控制信息,视频点播的各种控制基于DSM-CC协议实现.重点阐述了该系统端到端的逻辑结构和机顶盒相关软件的设计.从实现的原形系统分析,该系统可用于有线电视网络中,服务于所有的有线电视用户.     

具有可伸缩性的增强型高级锥形广播算法

镜像金字塔广播算法（MPB）采用镜像的方法来减少金字塔算法（PB）对用户缓存的要求。EMPB算法和APB算法则对该算法做了进一步改进以提高其性能。但APB算法并不具备可伸缩性和最好的性能。通过对这些算法的分析，提出了高效可伸缩高级锥形算法SAPB。该算法能适应不同用户缓存限制，并通过可伸缩参数的选择可获取比上述算法更好的性能，使VoD系统具有很好的灵活性和较强的用户环境适应能力。     

一种P2P环境下的VoD流媒体服务体系

在Internet上提供大规模的VoD服务是一项具有挑战性的工作.提出了一种基于P2P(peer to peer)方法的VoD服务体系PeerVoD,它能够以较小的服务器代价实现大规模的VoD应用.PeerVoD中的每个节点均使用定长的FIFO缓存队列来保存其最近所接收到的数据,以便为后续到达的节点提供服务.它具有如下特点:1) 采用分布式控制协议以支持节点的加入和离开,系统具有良好的可扩展性;2) 服务被中断的节点在进行中断恢复时,考虑了节点对目标节目接收的完整性.仿真实验表明:同等条件下,PeerVoD体系在服务器负载、节点加入时被拒绝的概率、网络资源利用率以及节目完整性等性能指标上,均优于同类体系P2VoD.     

动态段阈值机制在P2Cast VoD系统中的应用

本文对一种新型的视频点播系统P2Cast视频点播系统的关键技术进行了研究，针对段阈值在系统的可扩展性方面以及视频服务质量方面所起的重要作用，结合补丁流算法和客户节点的请求速率提出了一种嵌入动态调节段闲值机制的BF改进算法。该算法在一定程度上提高了P2Cast视频点播系统的性能。     

自治分布式视频服务器中动态数据迁移研究

通过对VoD服务器扩展性的分析，提出了一种并行视频服务器结构——自治分布式视频服务器，它的结构是在不断扩展的过程中形成的。分析了它的数据迁移特点，提出了一种动态数据迁移算法，实验结果表明该算法是有效的。     

一种基于IP网络流媒体传输的码流平滑算法

提出了一个视频点播解决方案，给出了服务器和客户机的系统实现和工作时序，重点描述了基于客户机预测分段的码流平滑实现机制(PPSA)，包括理论模型和实验仿真结果。它有效地屏蔽了解码器读取码流速率的抖动，使得服务器输出码流速率平稳，减少了对网络的冲击。该方案适用于对延迟不敏感的视频点播系统。