P2P实时影音分享技术与应用趋势

前言 过去几年当中,一种新的网络串流架构,点对点(Peer-to-Peer)网络架构快速的崛起,此种网络架构一开始用在于数据文件的交换传递,后来进而发展成实时(real-time)影音内容的广播技术,如NICE,ZIGZAG,Narada and Coolstreaming…等,而当P2P的技术运用于实时影音数据分享,即是近来讨论火热的P2P网络电视(IPTV),何谓IPTV呢?     

基于P2P架构下的移动全球眼视频监控系统

移动全球眼是中国电信基于移动网络推出的一种新型的视频监控类业务,目前在各行各业中已经有了很多成功的应用案例,为各行各业创造了不少价值。但目前该项业务行业应用较多数,个人应用较少,业务发展停滞不前,传统C/S网络架构的先天瓶颈限制了该项业务的发展规模和形式多样化。通过对移动"全球眼"视频监控系统的介绍,结合P2P在流媒体系统中的运用原理,通过相关的系统软件和网络架构改造,形成一个基于P2P的移动"全球眼"监控系统,并通过新老系统在实际应用过程中的性能对比测试,验证基于P2P的"全球眼"系统在业务能力方面的优势较目前系统更有利于此业务的未来发展趋势。     

浅析P2P协议在编程中的应用

随着计算机技术和网络技术的高速发展,不联网的应用程序已经难以满足人们的需求,网络应用程序越来越多出现在了人们的日常生活和工作中。文章主要针对P2P架构,结合P2P在.NET中的应用,对P2P的发展、结构以及应用进行了阐述和研究。     

用于协同工作的分组P2P网络

传统的协作系统存在固有的缺陷:系统可靠性和扩展性差,不能充分利用客户端资源。P2P系统不但架构灵活,有高可扩展性,而且能充分利用计算和网络资源。文章分析了协同工作系统采用P2P架构所具有的优点,并提出一个用于协同工作系统的分组P2P网络的设计与实现方案。     

P2P网络模式下的DRM体系架构

分析和总结了P2P网络模式和数字版权管理(DRM)技术体系.在学习P2P网络模式与DRM系统融合技术研究成果的基础上,按照P2P网络的分类,将其总结为4种体系,给出了每种体系的架构,并且指明了它们的不同.从数字版权管理、服务器和节点负载、安全性和计费的可靠性、分布式证书发行能力、网络的可扩展性等多个角度对这4种架构进行了分析和比较,给出了最后的评价结果.分析和讨论了目前存在的问题,最后指出了进一步的研究方向.     

一个P2P搜索引擎的架构和实现

P2P搜索技术是P2P研究中的一个重要的领域.文中介绍了一个基于P2P结构化覆盖网络的分布式搜索引擎的架构和实现.该搜索引擎采用了三层架构,良好的层次架构减少了搜索引擎核心算法与P2P覆盖网络协议和具体应用间的依赖,使得搜索引擎可以移植到不同的P2P结构化覆盖网络之上.由于P2P搜索过程中会消耗大量的网络带宽,所以该搜索引擎使用了一些优化算法,它们不仅减少搜索过程带来的带宽消耗,而且保证了系统的可伸缩性.     

电视节目制作网络监控系统的分析与设计

分析电视节目制作网络监控系统的组成与功能,提出网络监控系统架构,设计了一个基于通用网络管理协议的网络监控系统,实现实时全方位监控和管理,最后分析了网络监控系统对节目制作网络系统的影响。     

基于P2P视频监控技术的应急指挥系统研究

文章首先简要介绍了3G视频监控系统与P2P技术,然后着重从网络地址转移、传输模式和客户端功能设计这三个方面阐述基于P2P网络视频监控系统解决方案,最后指出P2P视频监控技术在应急通信指挥中的应用.     

P2P文件共享网络的不良信息监测

P2P技术作为一种新技术在为信息传递提供更宽广的舞台的同时,也给不良信息传播提供了新途径。近年来,P2P网络上的淫秽、色情和反动等有害信息传播盛行,几乎不受任何限制,这使得监管机构遭遇到前所未有的难题。由于技术手段的落后,如何时P2P网络上不良信息实施监控亟待解决和完善。Gnutella网络是无结构化P2P网络的代表,其同时在线的用户数目已超过100万。本文根据Gnutella网络结构的特点,对Gnutella网络上所共享的淫秽色情信息进行了实时监测,并对Gnutella用户所感兴趣的内容进行了相应的分析,为P2P文件共享网络的不良信息监控进行了初步的尝试。     

基于Zabbix的监控运维系统在勘察设计行业的研究与应用

随着勘察设计企业信息化的不断发展,网络服务器系统软硬件架构也日益复杂,企业面临着大量的应用程序、服务器、网络设备等的监控运维问题。为此,基于Zabbix开源平台构建了适合企业一体化信息体系现状的监控运维系统,实现了对企业各类软硬件的实时监控和故障报警,大大提高了运维效率,降低了运维人员的工作复杂度。     

基于公钥认证的P2P多点数据传输系统

近年来,多点数据传输成为一个热门话题,广泛应用于各种P2P网络中。随着网络资源的共享越来越被强化,由于对等网络缺乏集中化的管理,安全性难以保证,多点数据传输系统的大规模商业应用所面临的安全问题越来越突出。针对P2P网络的安全问题,设计了一种公钥认证模式来识别用户身份,并实现了一个多点数据传输系统,该系统包括文件分块下载、即时聊天及音频／视频服务等常见应用。     

Modeling and application of moderate prefetching strategy based on video slicing for P2P VoD systems

In peer-to-peer (P2P) video-on-demand (VoD) streaming systems,each peer contributes a fixed amount of hard disk storage (usually 2 GB) to store viewed videos and then uploads them to other requesting p...     

Timely traffic identification on P2P streaming media

Since the year of 2006,peer-to-peer (P2P) streaming media service has been developing rapidly,the user scale and income scale achieve synchronous growth.However,while people enjoying the benefits of th...     

基于流媒体技术的智能小区数字音频播放系统

介绍了流媒体技术的基本原理、网络传输协议及其传播方式,分析了传统智能小区数字音频播放系统中的不足,在原有基础上利用流媒体技术设计和实现了一个功能更为完善的数字音频播放系统。实验表明,该系统在音频服务器和录播终端均为PIII800M的PC机,网络为10Mb带宽LAN条件下完全满足智能小区音频播放要求。     

基于OMAP4460低带宽无线传输控制的设计与实现

移动监控系统面临功耗低、体积小、实时性强和带宽低的要求,提出了基于OMAP4460平台实现高清码流的实时传输和显示,采用低码率传输算法解决恶劣环境下的图像抖动和时延问题。充分利用OMAP4460功耗低、体积小的特性,双核架构的ARM核完成系统管理和控制,DSP核进行编解码发挥传输算法的网络友好性优势。实验结果表明,基于OMAP4460设备能在低带宽无线通道中,获得低时延、较小丢包率的音视频质量,实现低带宽下媒体流的流畅播放和实时性的要求。     

A Bayesian approach for user aware peer-to-peer video streaming systems

Peer-to-Peer (P2P) architectures for live video streaming has attracted a significant attention from both academia and industry. P2P design enables end-hosts to relay streams to each other overcoming the scalability issue of centralized architectures. However, these systems struggle to provide a service of comparable quality to that of traditional television. Since end-hosts are controlled by users, their behavior has a strong impact on the performance of P2P streaming systems, leading to potential service disruption and low streaming quality. Thus, considering the user behavior in these systems could bring significant performance improvements. Toward this end, we propose a Bayesian network that captures all the elements making part of the user behavior or related to it. This network is built from the information found in a cross-analysis of numerous large-scale measurement campaigns, analyzing the user behavior in video streaming systems. We validate our model through intensive simulations showing that our model can learn a user behavior and is able to predict several activities helping thus in optimizing these systems for a better performance. We also propose a method based on traces collection of the same user type that accelerates the learning process of this network. Furthermore, we evaluate the performance of this model through exploring its applications and comparison with non-contextual models.     

On the distribution of the product and ratio of products of EGK variates with applications

Video streaming over peer-to-peer (P2P) networks is a promising approach for scalable IPTV and online games. Distributing high-quality videos among users who employ numerous channels in multi-channel P2P live streaming systems, however, still suffers from many challenges arisen from the network size and dynamicity, channel resource imbalance, and bandwidth limitations. Other challenges also exist, including instability of peers, the peers’ low participation, large startup and playback delays, low quality of received video, and resource insufficiency in unpopular channels. In this paper, ReDePoly, with some levels of distributed intelligence, is proposed to reduce the bootstrapping delay and to increase the service quality. The key idea is to substitute agents with bootstrapping peers in the channels to model user behaviors and to share the aggregated knowledge among the agents to disseminate the learned models. Accordingly, the agents dynamically predict the behavior of participating peers to pre-assign them to the predicted channels and to parallelize the threads related to viewing behavior and channel switching. In case of congested channels, the new agents are distilled to mitigate the agent responsibilities. Simulation results show that the proposed approach outperforms the other existing methods regarding the channel switching delay, recovery delay, and quality of service.     

Accelerating peer-to-peer networks for video streaming using multipoint-to-point communication

Existing transport layer protocols such as TCP and UDP are designed specifically for point-to-point communication. The increased popularity of peer-to-peer networking has brought changes in the Internet that provided users with potentially multiple replicated sources for content retrieval. However, applications that leverage such parallelism have thus far been limited to non-real-time file downloads. In this article we consider the problem of multipoint-to-point video streaming over peer-to-peer networks. We present a transport layer protocol called R/sup 2/CP that effectively enables real-time multipoint-to-point video streaming. R/sup 2/CP is a receiver-driven multistate transport protocol. It requires no coordination between multiple sources, accommodates flexible application layer reliability semantics, uses TCP-friendly congestion control, and delivers to the video stream the aggregate of the bandwidths available on the individual paths. Simulation results show great performance benefits using R/sup 2/CP in peer-to-peer networks.     

车载式无线双模音视频传输监控系统设计与实现

基于CDMA2000和WCDMA的无线网络,设计并实现了车载式音视频监控系统,包括运行于后台的监控中心子系统和运行于终端的调用子系统.重点阐述了该监控系统中监控终端以及监控中心的软件设计和关键技术.系统在工程环境下进行了调用测试,测试结果表明,基于该设计的车载终端充分利用了CDMA2000和WCDMA网络的传输带宽,相对于单模的音视频传输,在传输效果上有较大的提高.