Multiple description coding with spatial-temporal hybrid interpolation for video streaming in peer-to-peer networks

INTRODUCTION Multimedia services over the Internet are be- coming popular due to the widespread deployment of broadband access. However, the conventional cli- ent-server architecture severely limits the number of simultaneous users, especially for bandwidth inten- sive applications such as video streaming. P2P net- works, on the other hand, offer a solution to the scalability problem. As a node joins a P2P network, it not only consumes resources but also contributes its bandwidth or comp…     

基于P2P流媒体技术的远程教育系统的设计

随着网络及流媒体技术的发展,越来越多的远程教育系统开始采用流媒体作为主要的网络教学方式.它可以提高网络课堂的质量,增强网络课堂的交互性.而基于P2P的流媒体可以充分发挥众多客户机的作用,有效利用客户机闲置的计算和存储资源,使客户机完成部分服务器的功能,降低服务器的负载和对网络带宽的占用率.因此,基于P2P的流媒体技术在远程教育中的应用已成为一种必然的趋势.在传统流媒体技术的基础上提出混合式结构的P2P流媒体模式,以进一步优化远程教育系统.     

Hybrid ants-like search algorithms for P2P media streaming distribution in ad hoc networks

Media streaming delivery in wireless ad hoc networks is challenging due to the stringent resource restrictions,po-tential high loss rate and the decentralized architecture. To support long and high-quality streams,one viable approach is that a media stream is partitioned into segments,and then the segments are replicated in a network and served in a peer-to-peer(P2P) fashion. However,the searching strategy for segments is one key problem with the approach. This paper proposes a hybrid ants-like search algorithm(HASA) for P2P media streaming distribution in ad hoc networks. It takes the advantages of random walks and ants-like algorithms for searching in unstructured P2P networks,such as low transmitting latency,less jitter times,and low unnecessary traffic. We quantify the performance of our scheme in terms of response time,jitter times,and network messages for media streaming distribution. Simulation results showed that it can effectively improve the search efficiency for P2P media streaming distribution in ad hoc networks.     

Efficient video-on-demand services over mobile datacast channels

[1]Engebretsen,L.,Sudan,M.,2002.Harmonic Broadcasting is Bandwidth-Optimal Assuming Constant Bit Rate.Proc.Annual ACM-SIAM Symposium on Discrete Algorithms.San Francisco,CA,USA. [2]ETSI,2005.IP Datacast over DVB-H:Content Delivery Protocols.ETSI Standard,Draft,V0.0.9. [3]Horn,G.B.,Knudsgaard,P.,Lassen,S.B.,Luby,M.,Rasmussen,J.E.,2001.A scalable and reliable paradigm for media on demand.IEEE Computer,34(9):40-45. [4]Hu,A.,2001.Video-on-Demand Broadcasting Protocols:A Comprehensive Study.Proc.IEEE Infocom.Anchorage,Alaska. [5]Huang,C.,Janakiraman,R.,Xu,L.,2004.Loss-Resilient Media Streaming Using Priority Encoding.Proc.ACM International Conference on Multimedia (MM‘04).New York,USA. [6]Jenka(c),H.,Stockhammer,T.,2005.Asynchronous Media Streaming over Wireless Broadcast Channels.Proc.of International Conference on Multimedia and Expo (ICME).Amsterdam,The Netherlands. [7]Luby,M.,Gemmel,J.,Vicisano,L.,Rizzo,L.,Handley,M.,Crowcroft,J.,2002a.Asynchronous Layered Coding (ALC) Protocol Instantiation.RFC 3450,IETF. [8]Luby,M.,Gemmel,J.,Vicisano,L.,Rizzo,L.,Handley,M.,Crowcroft,J.,2002b.Layered Coding Transport (LCT)Building Block.RFC 3451,IETF. [9]Luby,M.,Vicisano,L.,Gemmel,J.,Handley,M.,Crowcroft,J.,2002c.Forward Error Correction (FEC) Building Block.RFC 3452,IETF. [10]Luby,M.,Watson,M.,Gasiba,T.,Stockhammer,T.,Xu,W.,2006.Raptor Codes for Reliable Download Delivery in Wireless Broadcast Systems.Proc.Consumer and Communications Networking Conference (CCNC).Las Vegas,NV,USA. [11]Paila,T.,Luby,M.,Lehtonen,R.,Roca,V.,Walsh,R.,2004.FLUTE-File Delivery over Unidirectional Transport.RFC 3926,IETF. [12]Peltotalo,J.,Peltotalo,S.,Harju,J.,2005.Analysis of the FLUTE Data Carousel.Proc.10th EUNICE Open European Summer School.Colmenarejo,Spain. [13]Shokrollahi,A.,2003.Raptor Codes.Tech.Rep.DR2003-06-001,Digital Fountain. [14]TM-CBMS1361,2005.Proposal for Simulations for Evaluation of Application Layer FEC for File Delivery. [15]Xu,L.,2001.Efficient and Scalable on-Demand Data Streaming Using UEP Codes.Proc.ACM International Conference on Multimedia (MM‘01).Ottawa,Ontario,Canada.     

基于P2P的校园网流媒体平台的设计与实现

传统流媒体平台对服务器性能,网络带宽等条件要求较高,对校园网的视频应用服务有一定的局限性。为解决此问题,设计了一种基于P2P架构的流媒体视频教学平台,将流媒体技术的实时性和P2P网络的分布性完美地结合起来,实现了视频直播和点播功能。     

P2P网络内容分发中心化的研究与实现

P2P作为一种与服务器/客户端对立的网络架构,其应用近些年来在互联网中发展十分迅速,新的P2P应用更是层出不穷.分析P2P网络内容分发中心化时流媒体服务器之间的数据传输,指出它们的优缺点,结合CDN和P2P关键技术在网络中的应用,提出了轻量级的P2P传输系统,对网络流量、资源分块和分段大小的控制,提高资源查找的效率,从而简化P2P资源的查找实现     

P2P网络交互式视频点播服务的性能改进

P2P网络交互式视频点播服务中改善用户体验的关键在于减少跳转延时及提高本地缓存的命中率。本文在vEB树基础上增加了跳转到概率较大片段节点的链接,对LRU和LFU算法进行改进提出了基于价值的缓存替换算法。在NS-2环境下进行了模拟实现,实验数据表明改进后的vEB树结构有效地减少节点的跳转延迟,基于价值的缓存替换算法提高了节点片段的命中率。     

基于P2P流媒体系统的实现研究

传统流媒体系统,受带宽和服务器限制,难以支持大规模并发客户。针对该问题,介绍了当前用P2P技术实现流媒体系统的现状,探讨了P2P的流媒体系统的系统结构及关键技术,分析了存在的问题,最后指出了P2P流媒体系统发展的研究方向。     

Rate-distortion optimized bitstream switching for peer-to-peer live streaming

Peer-to-peer （P2P） technology provides a cost-effective and scalable way to distribute video data. However, high heterogeneity of the P2P network, which rises not only from heterogeneous link capacity between peers but also from dynamic variation of available bandwidth, brings forward great challenge to video streaming. To attack this problem, an adaptive scheme based on rate-distortion optimization （RDO） is proposed in this paper. While low complexity RDO based frame dropping is exploited to shape bitrate into available bandwidth in peers, the streamed bitstream is dynamically switched among multiple available versions in an RDO way by the streaming server. Simulation results show that the proposed scheme based on RDO achieves great gain in overall perceived quality over simple heuristic schemes.     

A P2P streaming service architecture with distributed caching

Multimedia streaming served through peer-to-peer (P2P) networks is booming nowadays. However, the end-to-end streaming quality is generally unstable due to the variability of the state of serve-peers. On the other hand, proxy caching is a bandwidth-efficient scheme for streaming over the Internet, whereas it is a substantially expensive method needing dedicated powerful proxy servers. In this paper, we present a P2P cooperative streaming architecture combined with the advantages of both P2P networks and multimedia proxy caching techniques to improve the streaming quality of participating clients. In this frame- work, a client will simultaneously retrieve contents from the server and other peers that have viewed and cached the same title before. In the meantime, the client will also selectively cache the aggregated video content so as to serve still future clients. The associate protocol to facilitate the multi-path streaming and a distributed utility-based partial caching scheme are detailedly dis- cussed. We demonstrate the effectiveness of this proposed architecture through extensive simulation experiments on large, Inter- net-like topologies.     

高职院校校园视频点播系统的解决方案

校园网一般由教学平台、信息平台和管理平台组成。其中信息平台内容最为丰富多彩,它包括多媒体网络教室、VOD视频点播系统以及视频会议系统,其中尤以VOD视频点播、AOD音乐点播在学校网络教学中的发展最为迅速。在学校内的全部终端都可以对教学视频服务器中视频课件实现同步、异步并发点播调用,在给学生提供辅助教学手段的同时,也引发一场由传统僵化的教育模式向现代化网络教育转变的创新革命。     

P2P流媒体传输技术的应用研究

研究了应用层组播的P2P流媒体传输技术,给出了应用层组播树的结构,使得树的结构能够保证用户计算机不互相传送同样的数据而形成数据风暴.     

Content subscribing mechanism in P2P streaming based on gamma distribution prediction

P2P systems are categorized into tree-based and mesh-based systems according to their topologies. Mesh-based systems are considered more suitable for large-scale Internet applications, but require optimization on latency issue. This paper proposes a content subscribing mechanism (CSM) to eliminate unnecessary time delays during data relaying. A node can send content data to its neighbors as soon as it receives the data segment. No additional time is taken during the interactive stages prior to data segment transmission of streaming content. CSM consists of three steps. First, every node records its historical segments latency, and adopts gamma distribution, which possesses powerful expression ability, to express latency statistics. Second, a node predicts subscribing success ratio of every neighbor by comparing the gamma distribution parameters of the node and its neighbors before selecting a neighbor node to subscribe a data segment. The above steps would not increase latency as they are executed before the data segments are ready at the neighbor nodes. Finally, the node, which was subscribed to, sends the subscribed data segment to the subscriber immediately when it has the data segment. Experiments show that CSM significantly reduces the content data transmission latency.     

Key technologies for the novel distributed numerical control integrated system

1.IntroductionTheeconomicglobalizationandmutablemarketgiverisetotheglobalizationofmanufacture.Manufacturingcompaniescooperatewitheachother,meanwhile,theyconfrontswithmoreintensemarketcompetition.Enterprisesadoptadvancedmanufacturingtechnologies,equipmentsandmodernmodessoastosurviveanddevelopwell,andthentheautomaticprocessingworkshopsappearwherenewandoldNCmachinetoolsemployinginhomogeneousnumericalcontrolsystemscoexist.Toincreasetheefficiencyofmachinetoolsandimprovetheproductionmanagementlevel…     

数字图书馆中流媒体技术的应用

为了在数字图书馆中提供高效的视频点播服务,重点剖析了卡内基梅隆大学Information数字视频图书馆系统和Apple公司的DRAWIN系统。在此基础上,提出了一个基于Web的视频点播解决方案。     

Streaming and congestion control using scalable video coding based on H.264/AVC

INTRODUCTION Streaming of multimedia data over the Internet has rapidly increased in recent years. All commercial applications and most research in video streaming use conventional hybrid video coding. To adapt the data transmission rate on the server to the varying bandwidth caused by congestion in the Internet or to different available bandwidths of different clients, the simulcast solution is widely applied (Balk et al., 2003; Feamster et al., 2001; Schierl and Wiegand, 2004). A larg…     

基于无线串口服务器的DNC实验系统设计与开发

为了适应当今制造业对网络化制造人才的需求,在分析了数控实验室现场实际条件的基础上,以无线串口服务器为核心,构建了无线DNC(direct numerical control)实验网络,建立了无线DNC实验系统软件框架,并探讨了系统实现中的一些关键技术,开发了一个无线DNC实验系统。该系统具有机床状态监控、NC程序收发、NC程序及相关文档管理等功能。使用结果表明,该实验系统部署简单、使用方便、维护工作量少,适合学校数控实验室使用。     

基于P2P网络的反垃圾邮件系统的设计

垃圾邮件已成为当今邮件系统的主要问题,垃圾邮件发送者通过伪装邮件来逃避反垃圾邮件系统的检测.针对目前的垃圾邮件过滤器大多数单机运行,所能获得的数据和信息较少,效率较低的问题,本文提出了一个点对点(P2P)的无服务器的E-mail系统的体系结构,系统测试结果表明,该系统结构有效地实现了相似邮件的聚集,从而达到了过滤垃圾邮件的目的.     

P2P网络借贷投资者接受模型分析与构建

在分析技术接受模型（technology acceptance model,TAM）和任务技术匹配（task technology fit,TTF）整合的必要性的基础上,运用基于TAM和TTF整合的信息技术接受模型,采取二手资料和开放式问卷调查获取影响因素,构建出P2P网络借贷投资者接受模型。模型研究表明:感知风险是阻碍投资者使用P2P平台进行投资的最重要的影响因素。感知有用、感知收益和感知信任从一定程度上能促进投资者使用P2P平台进行投资。政策法规、P2P平台的质量、主观规范、感知行为控制对P2P平台投资也会产生一定的影响。同时,结合本研究模型提出了针对P2P平台应用和推广的建议。     

基于P2P的VOIP技术研究

在VOIP中引入P2P技术,可以有效缓解资源有限的难题,改善网络的可伸缩性和可靠性。本文即是在VOIP与P2P结合考面做了有益的尝试,提出了基于混合P2P结构的VOIP模型,详细论述了模型中节点的操作,并对其服务质量（QoS）进行了研究,结合VC算法提出了一个带抖动控制的算法（VC-Jitter算法）。最后对提出的系统进行了仿真实验,结果分析表明本文所提模型和算法是有效的。