新闻 - 体育 - 娱乐 - 财经 - IT - 汽车 - 房产 - 女人 - 短信 - 彩信 - 校友录 - 邮件 - 商城 - BBS - 搜狗 
搜狐首页 >> 娱乐频道 >> 电影 Movie >> 影坛动态 >> 第二届中国国际新媒体产业论坛 >> 相关报道

工程院院士邬江兴“3Tnet与IPTV的未来发展”

YULE.SOHU.COM 2005-06-06 15:51  来源: 搜狐娱乐
页面功能 【我来说两句(0)】 【收藏本文 收藏本文】 【热点排行】【推荐】【字体: 】【打印】 【关闭
张靓颖沈阳拍写真
图:关咏荷产后家庭照首曝光
章子怡愿为"他"息影结婚生子
小S婆婆4千万豪宅慰劳媳妇
大牌明星们的卖身契曝光(图) 徐静蕾剪不断理还乱的情感历程
蒋雯丽曾落榜张国立曾当工人
林青霞首度回应婚变传闻

  新一代高速网络发展与应用- 3Tnet与IPTV的未来发展

  邬江兴教授,工程院院士

  国家八六三计划3Tnet重大专项总体组

  国家数字交换系统工程技术研究中心

  摘要:本文首先介绍了国内外网络电视(IPTV)业务的发展趋势,分析了当前互联网承载IPTV业务时所面临的主要技术问题。然后,叙述了西方发达国家在高速网络方面的重要计划,指出了我国在发展高速网络方面所进行的努力,特别是国家863计划支持的高性能宽带信息网(3Tnet)重大项目,正是我国在通信网络领域追赶西方发达国家的重要举措。最后,详细介绍了3Tnet重大项目的主要创新、所取得的研究成果等,并对新一代网络与业务的发展作了简单预测。

  一 国内外网络电视业务发展趋势

  1.1 全球通信业务发展总体趋势

  o 从服务对象上,全球通信业务越来越重视两个方面

  n 提倡以人为本,提供高质量、个性化、人性化通信服务;

  n 重视全民共享,推行无所不在的服务,缩小数字鸿沟。

  o 从业务特征上,网络业务呈现移动化、宽带化、多媒体化的发展趋势

  o 许多国家越来越重视通信网络和服务业在建设信息社会与可持续发展中的基础作用

  1.2 通信业务主体发生变化

  o 数据业务(特别是IP业务)对PSTN话音业务冲击明显

  n 过去3年骨干网流量年增长率260%,2004年第3季度省际IP带宽是话音带宽的10倍;

  n IP流量占90%数据带宽;

  n 预计未来5年骨干网带宽需求年增长约80%;

  o 移动网替代固定网趋势正日益加速

  n 2003年10月移动用户超固网用户;

  n 2003年2月移动业务收入占50.28%;

  n 移动通话次数接近,时长超过固网。

  1.3 IP业务中以视频流媒体为主

  o 简单推算

  n 若视频流媒体服务(IPTV,VoD)的用户数从0.01%增加到1%,则其流量在整个IP业务总流量中将从9%增加到90%;

  o 两点推论

  n 在IP数据业务中唯视频流媒体服务独尊;

  n 解决了网络支持流媒体服务问题,也就解决其他业务可能存在的问题。

  o IPTV是宽带市场的主要推动力!

  1.4 IPTV业务全球趋势预测

   Strategy Analytics对全球IPTV业务预测:2008年将达到2000万以上用户,全球IPTV前景光明。

  图1a 全球IPTV预测用户数增长趋势 图1b 全球区域IPTV用户数增长趋势

  1.5 影响IPTV发展的因素分析

  o 据中国电信用户调查分析,影响用户购买IPTV业务的主要因素有:内容(含更新速度)、价格、图像质量、网络质量

  o 用户对内容要求

  n 视频点播以电影、电视剧为主;

  n 信息服务以社会、体育、财经、彩票为主;

  n 互动游戏以休闲、益智、对抗类游戏为主;

  n 远程教育以时尚、烹饪、职业教育为主。

  o 用户对终端要求

  n 多数人喜欢机顶盒+电视机模式;

  n 目前市场上机顶盒的质量与外观都有不足。

  o 用户对网络要求

  n 开机连接启动速度、网络连接稳定性、频道切换速度等存在问题

  1.6 IPTV系统的一般组成

  图2 IPTV系统组成

  1.7 基于ADSL的IPTV解决方案

  图3 一种IPTV解决方案

  二 在互联网开展网络电视业务面临问题

  2.1 视频流媒体业务的特征

  o 与传统IP数据业务(FTP、HTTP、Telnet、Email等)相比,视频流媒体(IPTV、VoD等)需消耗更多网络带宽

  o “流”的本质 – 希望网络具有面向连接的特性

  n 数据包有时间顺序(时序约束);

  n 数据包必须在限定时间内到达(有界时延抖动:TCP无用);

  n 数据包丢失率尽量小(优先丢失);

  n 在流数据传送期间需持续占据网络带宽(最小带宽保证)。

  2.2 互联网的本质缺陷

  o Internet哲学是“尽力而为”;

  o IP是纯粹的分组交换体制;

  o 无法保证端到端QoS(带宽、数据包丢失、包延迟等);

  o 基于大量IP路由器分布式互联而形成的互联网是不可预测的,其行为是异常复杂的;

  o 现有QoS保障协议(例如DiffServ、IntServ、MPLS等)试图修补Internet的QoS缺陷,但是也只能在IP基础上提供尽可能好的QoS,不能从根本上解决QoS问题!

  2.3 应积极探寻新的网络体系

  o 视频流媒体业务中“流”的本质特征要求新一代互联网具有面向连接的特性

  n 要求带宽独占和流速平稳;

  n 要求大规模并发和组播;

  n 要求突发数据访问;

  o 在网络边缘用户设备接入时又必然要求IP

  n IP的开放特性(允许子网异构,全局寻址,透明);

  n 允许各类终端访问网络(普遍连接性要求);

  n 汇聚各种异构业务源的上下行流量(多路复用)。

  三 西方发达国家高速网络发展计划简介

  3.1 美国高速网络计划

  o NGI,Internet2

  o 100×100研究计划

  n 主要目标:美国NSF资助,提出到2010年100Mbps到1亿家庭用户、1Gbps到1百万中小企业,解决端到端QoS;

  n 设计理念;致力于全新网络构架,不考虑后向兼容,只考虑前向兼容;

  n 具体内容:除了考虑带宽、迟延、迟延抖动、安全等性能参数外,特别强调无处不在的接入、用户和网络运营的经济性、安全抗攻击性和易管理性等。

  3.2 欧盟高速网络计划

  o e-Europe2002的重点是宽带接入

  o e-Europe2005主要关注如何推进业务、应用和内容,致力于宽带架构和安全事务的发展,提出了现代化的在线公众服务(电子政府、e-learning和e-health)和具有推动力的电子商务环境及应用支持基础(普遍可用的宽带接入和信息安全架构)的目标

  3.3 日本高速网络计划

  o e-Japan战略计划使日本2003年实现宽带网络环境

  o 2004年6月日本提出以发展Ubiquitous社会为目标的U-Japan构想,希望在2010年在日本建设成一个“anytime, anywhere, anything, anyone”可上网环境,其四大目标:

  n 实现何时何地都可以舒适地利用网络的社会;

  n 实现可以持续创造新商业及服务的社会;

  n 实现任何人都可以安心且安全生活的社会;

  n 实现充满活力的社会。

  o 日本政府预测与U-Japan有关的市场规模达87.6万亿日元,影响日本经济120.5万亿日元

  3.4 发展新一代网络是许多国家的战略选择

  o 西方发达国家的战略选择

  n 把对新一代网络技术的掌握视为提升经济实力和国家竞争力的重要手段;

  n 高度重视通信网络和信息服务业在建设信息社会与推进可持续发展中基础性作用;

  n 投入大量人力、物力,提出战略发展计划,分阶段、有步骤实施,取得明显成效。

  四 我国863计划3Tnet重大专项介绍

  4.1 十五期间我国网络发展计划

  o 中国各级政府部门高度重视高速网络的发展

  n 科技部八六三计划:高性能宽带信息网(3Tnet)

  n 信息产业部:NGN发展战略研究(考虑运营和电信IP产业)

  n 国家发改委:中国下一代互联网示范工程(CNGI,重点解决IPv6)

  n 国信办:因特网技术现状、问题和发展趋势的研究(重点解决网络信息安全问题)

  n 自然科学基金委:网络与信息安全重大研究计划

  4.2 3Tnet的来源

  o 3Tnet是“高性能宽带信息网”的简称,是国家863计划“十五”期间信息领域重大科技专项;

  o 国务院8号文件的要求:贯彻创新性、先进性、开放性和示范性的原则,以新产品和新业务开发为中心,自主研制Tbps级路由、交换、传输设备以及应用支撑环境,建设试验示范网,促进我国区域经济跨越式发展,使我国在新一代通信网核心技术方面进入世界前列。

  4.3 3Tnet的目标

  o 自主研制Tbps网络设备,在长三角促进地方政府和运营公司建设下一代可运营、支持大规模并发流媒体和交互式多媒体业务的高性能宽带信息示范网

  n 技术目标:突破关键技术屏障,自主研制Tbps级的光传输系统、自动交换传送网络、IPv4/v6双栈路由器等核心节点设备,研究开发相应的网络支撑环境;

  n 网络目标:用Tbps级节点设备、网络支撑环境和相关业务资源促进地方政府和运营公司,建立一个实用化的、可管理、可运营的广域高性能宽带信息网;

  n 应用目标:从宽带流媒体和互动多媒体业务开始,发展多种音视频服务,面向多种增值业务,推进示范区域信息一体化进程。

  4.4 3Tnet的研制思路

  o 基于业务特征驱动网络渐进演变的一般规律,研究3Tnet整体构架(核心网和边缘网);

  o 研究核心网对流媒体业务的支持;

  o 研究接入网对端到端带宽的保证(40Mbps);

  o 开展大规模试验和示范应用,以验证3Tnet的体制、技术、设备、业务的运营支撑环境和商业模式等。

  4.5 3Tnet的主要业务

  o 支持流媒体业务:网络电视(IPTV)或视频点播(VoD)

  n 利用[机顶盒+电视机]、电脑等终端设备,通过3Tnet接入网,按频道接收电视节目(包含HDTV);

  n 或按节目表点播视频节目。

  o 支持话音业务:VoIP

  n 利用[机顶盒+电视机]、电脑等终端设备,通过3Tnet接入网,打IP电话

  o 支持上网业务:WWW,Email,FTP等

  n 浏览网页、收发邮件等

  五 3Tnet的主要创新和重要成果介绍

  5.1 3Tnet的整体构架

  o 核心网:使用电路交换ASON;

  o 边缘网:使用大规模汇聚路由器ACR;

  o 基本特征:电路和分组混合的交换体制。

  图4 3Tnet核心网与边缘网整体构架

  5.2 3Tnet 的核心网(ASON)

  o 上海—杭州:基于40Gbps的Tbps密集波分复用(DWDM)光传输系统

  n 支持到80×40Gbps能力

  o 城域网:Tbps级自动交换传送网ASTN

  n 具有Tbps交换容量、多类型业务接入、动态资源分配、自动连接控制和网络保护恢复等功能的自动交换光网络(ASON)节点设备;

  n 突发交换式连接、组播。

  图5 核心网拓扑

  5.3 3Tnet 的接入网(ACR)

  图6 接入网与ACR组成

  o 高度简化接入网络的拓扑结构(超级扁平树结构,端到端2跳),提供QoS保证和端口流量控制;

  o 支持大规模用户端口数(最多可扩展到6万个端口);

  o 支持二层隔离和三层受控互访,支持一体化网管;

  o 支持IPv4/v6;

  o 支持100个频道数字电视业务,最大可支持30路HDTV和70路SDTV的组播或总带宽≤1Gbps电视频道数;

  o 支持基于IPv4/IPv6的激活和休眠状态的受控组播树,组播树数量大于100个,用户在组播树间的切换时间:75%的情况下小于0.75s;85%小于1s;最长切换时间小于1.2s;

  o 支持基于流聚合的动态组播树,提供VOD业务,动态组播树的数量大于2000个,流聚合的最大时延小于1分钟。

  5.4 3Tnet的拓扑图

  图7 3Tnet的实际部署拓扑图

  5.5 3Tnet对IPTV的支持

  o IPTV的内容分发方式:ASON组播 + IP 组播

  o 性能指标:

  n 2万个IPTV用户

  n 70路SDTV(6Mbps)

  n 30路HDTV(20Mbps)

  o 主要瓶颈:网络带宽

  图8 3Tnet支持IPTV的框架

  5.6 3Tnet对VoD的支持

  o VoD内容分发方式

  n 单播;聚链组播;

  n CDN框架:局部化VoD业务量,降低核心网络负载

  o 性能指标:2000个并发用户;100路备选节目

  o 主要瓶颈:网络带宽;服务器能力

  图9 3Tnet支持VoD的框架

  5.7 3Tnet的运营支撑环境

  o 从媒体前端、媒体传输、运营保障、用户接入等方面入手,构建了集IPTV(含HDTV、互动)、VoD业务于一体的综合运营服务平台;

  o 实现了用户一点认证付费,业务运营商(包括视频业务运营商、话音业务运营商、各种数据业务运营商等)、网络运营商、驻地网运营商的可独立管理各自业务和可信分帐的运营机制。

  5.8 3Tnet支持IPTV的技术关键

  o ASON链路组播确保IPTV直播到边缘汇聚路由器ACR;

  o ASON突发连接确保VoD节目下载到边缘媒体服务器;

  o ACR受控组播技术实现对IPTV用户认证和授权;

  o ACR的大规模汇聚和超强交换技术确保用户40Mbps带宽;

  o 智能化内容分发提高系统的整体性能和效率;

  o 运营支撑环境保证系统可管理和可运营。

  5.9 3Tnet的主要成果列举

  o Tbps传输:全球第三个实际开通的、可扩展到80X40 DWDM传输系统;

  o Tbps交换:全球最早提出的基于ASON突发传输和组播的城域网;

  o Tbps路由:融合电路交换和分组交换优势,研制大规模汇聚路由器;

  o IPTV业务:实时快速分发的城域ASON网和大规模接入路由器,确保对IPTV业务支持,并率先探索IPTV商业运营模式;

  o 规模试验:国内规模最大的支持IPTV(含HDTV)业务的实验网 – 拥有20000用户,且用户可独享40Mbps带宽;

  o 产业推进:引领网络技术创新和国家(国际)标准的制定,为宽带网络与IPTV形成产业链奠定基础。

  5.10 3Tnet的推广应用

  o 上海市政府2004年启动eShanghai重大研究计划,按照部市合作要求,全力推动3Tnet走向实际应用

  n E-Entertainment

  o 在闸北区开展IPTV业务

  o 在3Tnet上开展网络游戏业务

  n E-Learning

  o 在3Tnet上开展网络教学

  n E-Health – 通过3Tnet为医院和社区服务

  n E-Show – 通过3Tnet展示上海经济建设成果

  六 下一代高速网络与业务的发展趋向

  6.1 未来网络的发展趋势

  o 业务特征持续影响网络构架演变

  n 纯粹由IP路由器分布式互联所构成的互联网 – 逐步消亡;

  n 混合交换体制(分组交换中考虑面向连接) – 开始兴起;

  n 彻底解决端到端QoS问题 – 奋斗目标;

  n 从核心网到边缘网,光纤通信技术与设备将带来网络巨变;

  n IPv4逐步过渡到IPv6;

  n 发展宽带移动接入,满足泛在应用需求;

  n 还需考虑安全、可控、管理、经济等问题;

  6.2 3Tnet的下一步计划

  o 3Tnet在核心网、边缘网、流媒体业务等方面所取得的成功经验将直接影响我国新一代网络与服务技术的未来走向,提出更多新的研究课题;

  o 建立面向大规模实际用户的国家级新一代网络与业务测试床将是我国十一五期间的重大战略举措,也是赶超西方发达国家网络技术发展水平的难得机遇;

  o 我们将在测试床上开展网络体制构架、重大网络设备、全新类型业务、业务运营模式等诸多方面继续开展公关,继续引领我国网络技术的发展。

  七 结论

  o 以IPTV为核心的大规模并发流媒体很快成为高速网络的主流业务;

  o IPTV等流媒体业务催生新一代高速网络的体系构架;

  o 经过四年艰苦努力,3Tnet重大项目已取得许多创新的研究成果,3Tnet网已经是支持IPTV等并发流媒体业务的综合性业务的高速网络,3Tnet计划的成功实践将对新一代高速网络发展提供许多有益提示;

  o 新一代高速网络蕴含巨大商业机会,需持续不断的技术创新!

  The Development of a New Generation of High Speed Network-

  The Future Development of 3TNet and IPTV

  Prof. Jiangxing Wu

  Academician of Chinese Academy of Engineering

  PI of 863-3TNet Project, NDSC

  Abstract: This paper first introduces development trend of IPTV with an analysis of current technology difficulties of IPTV traffic transportation. A brief description of current high-speed network projects of developed countries is given which guides our effort to development a new generation high speed network, especially the 3TNet project under the sponsorship of the 863 Plan. Finally, the innovations and achievements from 3TNet are presented with a tentative prediction of the next generation network and application development.

  1. The Development Trend of IPTV

  1.1 Overall Trend of Global Communication Traffic

  o Two aspects is stressed for network services

  n Provide high quality, personalized communication service

  n Provide ubiquitous service

  o Network traffic has trends of mobility, broadband and multimedia

  o Many developed countries see the fundamental effect of communication network on an information society and sustainable development

  1.2 The Compisition of Network Traffic is Changing

  o Data traffic (especially IP traffic) has an obvious impact on PSTN voice traffic

  n Backbone traffic has a growth of 260% in the past 3 years; IP traffic in 10 times great than voice traffic in the third quarter of 2004

  n IP traffic occupies 90% of the bandwidth

  n Hopefully, backbone bandwidth will be growing at a rate of 80% 5 years

  o Mobile network is replacing wired network

  n In Oct. 2003, mobile users began to be preponderant over PSTN’s

  n In Feb. 2003, mobile traffic occupied 50.28% of total revenue

  n The number of mobile calls is close to that of wired network and mobile call durations is longer

  1.3 Major IP traffic is video streaming media

  o Simple Estimation

  n If video streaming media( such as IPTV and VoD) users grow from 0.01% to 1%, their traffic will grow from 9% to 90%

  o Two Inferences

  n Video streaming traffic is preponderant in IP traffic

  n If the network solves IPTV problem, it solves other traffic problems

  o IPTV is the major drive behind broadband market

  1.4 The Global Trend of IPTV

   Strategy Analytics predicted that: IPTV user number will be over 20 million in 2008

  Fig. 1a Prediction of IPTV user number growth Fig. 1b Global IPTV user growth

  1.5 Factors that affect IPTV development

  o According to China Telecom, factors that affect user's decision to by IPTV: content, price, image quality, network quality

  o User's requirement on content

  n Majority content of VoD should be movie and TV

  n Information service should include sports, financial report and lottery information

  n Interactive game should be recreational and intelligent ones

  n remote education should include fashion, cooking and occupation education

  o User's requirement on terminals

  n Prefer TV + Set-top Box

  n Current Set-top Box's quality and appearance is not good

  o User's requirement on network

  n Start-up speed, network stability and channel switching time problems

  1.6 Anatomy of an IPTV System

  Figure 2 IPTV Configuration

  1.7 ADSL-based IPTV Solution

  Figure 2 One IPTV System based on ADSL

  2 ADSL-based IPTV Solution

  2.1 Characteristics of video streaming traffic

  o Compared with traditional IP traffic(FTP, HTTP, Telnet, Email), video steaming (IPTV and VoD) costumes more bandwidth

  o The nature of stream - demand a connection oriented network

  n Datagram is timely ordered

  n Datagram must arrive in time subject to constraints

  n Datagram loss must be small

  n Continuously occupy bandwidth during data transmission

  2.2 The fundamental drawbacks of the Internet

  o The philosophy of Internet is "best effort"

  o IP is a pure packet swathing system

  o No guarantee of end-to-end QoS(bandwidth, packet loss, delay)

  o Internet that is interconnected by IP routers is no predictable, and too complex

  o Current QoS protocols(DiffServ, IntServ, MPLS) try to solve the QoS problem but fail to solve this problem fundamentally

  2.3 Seeking New Network Architecture

  o Streaming media demands that new architecture is of connection-oriented virtue

  n Demand bandwidth occupy and stable flow rate

  n Demand large-scale concurrency and multicast

  n Demand burst data access

  o IP is necessary at edge network where users access

  n The openness of IP (heterogeneous sub networks, global address, transparency)

  n Allow different terminals to access network (ubiquitous access)

  n Multiplexing different traffic

  3 High Speed Network Development Plans

  3.1 U.S. High Speed Network Plans

  o NGI,Internet2

  o 100×100 Research Plan

  n Main target: Sponsored by NSF, proposes that 100 million families access internet at 100Mbps, and solving end-to-end QoS

  n Design concept: A new network architecture, no backward compatibility and only forward compatibility

  n Tasks: Stressing over ubiquitous access, economy, anti-attack and easy management besides bandwidth, delay, jitter and security

  3.2 European High Performance Network Plans

  o Main target of e-Europe2002 is broadband access

  o E-Europe2005concerns traffic, application and content. It provides broadband architecture and secure transaction, suggests contemporary online public service (e-government, e-learning, e-health), e-commence and application support framework (ubiquitous accessible bandwidth and information security)

  3.3 Japan High Performance Network Plans

  o Strategic plan aims to realize broadband environment in Japan in 2003

  o June 2004, Japan proposes U-Japan to develop an ubiquitous society, hoping to build an "anytime, anywhere, anything, anyone" accessible network with four targets

  n Realize a society in which anytime and anywhere network is accessible

  n Realize a society in which we can create continues commerce and service

  n Realize a society in which anyone can live a secure life

  n Realize a society with vitality

  o Japan government predict that U-Japan relate market will sum up to 87.6 trillion yan and have an impact of 120.5 trillion on Japan economy

  3.4 A new network architecture is a strategic choice for developed countries

  o Consider the next generation network architecture as a way to improve competitiveness and economy

  o Highly stressed over the development of communication network and service in the realm of constructing a information society

  o Funnel in staffs, devices to propose a strategic plan with several steps to realize it

  4 The Proposal of China's 3TNet

  4.1 China's Network Plan from 2000 to 2005

  o China highly regards the development of high speed network, for example, 863 3Tnet Project initialized in 2001

  4.2 The origin of 3Tnet

  o 3TNet is the abbreviation for the high performance broadband information network . It is a critical project under the sponsorship of the 863 Plan

  o The 8th file from State Council states: it must be innovative, pioneering, open and illustrative with a focus on new traffic. We must make our own Tbps level routers, switches, transportation devices and supporting environment. We must build a test bed to promote economic development and make ourselves top ones among those countries that developed new generation high performance communication network

  4.3 The target of 3Tnet

  o Independently develop Tbps network devices. Develop an operable network that supports large scale concurrent video streaming traffic and interactive multimedia traffic.

  n Independently develop Tbps network devices. Develop a operable network that supports large scale concurrent streaming traffic and interactive multimedia traffic.

  n Technology target: independently develop Tbps optical transportation system, ASTN, IPv4/IPv6 dual-stack routers and the corresponding supporting network environment

  n Network target: Promote local operation of companies and government of this network with these Tbps network devices. Build a practical, manageable, operable, wide-area high performance network

  n Application target: On the basis of broadband streaming traffic and interactive multimedia traffic, develop various streaming services and value-adding service

  4.4 Development of 3Tnet

  o Based on the principle of traffic driven network evolution, we study the overall architecture of 3Tnet(core and edge network)

  o Study core network capacity to support stream media traffic

  o Study end-to-end QoS of access network(40Mbps)

  o Begin large scale simulation and application to prove the architecture, technology, device, traffic and supporting environment of 3Tnet

  4.5 Major Traffic in 3Tnet

  o Streaming traffic: IPTV or VoD

  n Use terminals such as [Set-top box + TV], computer to access 3tnet and receive TV program using channel (including HDTV)

  n Receive video program by EPG

  o Voice traffic: VoIP

  n Use terminals such as [Set-top box + TV], computer to access 3tnet and make IP phone calls

  o Web traffic: WWW,Email,FTP. E.g.

  n Web page browsing and email

  5 The Innovations of 3TNet

  5.1 Overall Architecture of 3Tnet

  o Core network: ASON circuit switching

  o Edge network: use large-scale convergence router ACR

  o Basic feature: mixture of circuit and packet switching

  Figure 4 Overall Architecture of 3Tnet (Core and Edge)

  5.2 Core network of 3Tnet (ASON)(ASON)

  o Shanghai—Hang Zhou:40Gbps based Tbps(DWDM)optical transporting system

  n Support 80×40Gbps capacity

  o Metropolitan network:Tbps automatic switching transportation ASTN

  n Tbps switching capacity、multiple traffic access、dynamic resource allocation、automatic error recovery enabled (ASON) devices

  n Burst switching mode connection, multicast

  Figure 5 Core Network

  5.3 Access Network of 3Tnet (ACR)

  图6Access network and ACR

  o Highly simplifies topology of access network(super-flat tree structure with 2 end-to-end hops), provides QoS guarantee and port traffic control

  o Support large-scale number of user ports(extensible to 60000)

  o Support second level segregation and third level access control, support integrated network management

  o Support IPv4/IPv6

  o Support 100 channels of DTV, maximum 30 channels of HDTV and 70 channels of SDTV with total bandwidth ≤ 1Gbps

  o Support IPv4/IPv6 controlled multicast tree in activated and hibernating mode, with number of multicast trees over 100. Switching time between multicast trees: less than0.75s under 75% circumstance; less than 1s under 85% circumstance; and maximum time is 1.2s

  o Support flow multiplexing based dynamic multicast tree. provide VoD traffic with dynamic multicast tree number over 2000 and flow multiplexing time less that 1 minute

  5.4 Topology of 3Tnet

  Figure 7 Deployment of 3Tnet

  5.53TNet’s support for IPTV

  o Distribution method for IPTV contents

  n ASON multicast + IP multicast

  o Current Capability

  n 20000 IPTV users

  n 70 SDTV(6Mbps)

  n 30 HDTV(20Mbps)

  o Major bottleneck : bandwidth

  Figure 8 IPTV over 3Tnet

  5.6 3TNet’s support for VoD

  o VoD distribution method

  n Unicast and Multiplexing multicast

  n CDN framework:localized VoD traffic to reduce core network overhead

  o Performance standard:2000 concurrent users 100 programs

  o Major bottleneck bandwidth Server capacity

  Fig. 9 VoD over 3Tnet

  5.7 3TNet‘s Operational Environment

  o From media forefront, media transport, operation guarantee, user access, to construct IPTV, VoD based integrated service platform

  o To realize that user pays at one place and traffic operator, network operator, local network operator manage its own traffic independently

  5.8 Key Tech of 3TNet to Support IPTV

  o ASON link multicast ensures that IPTV is transported to ACR

  o ASON burst connection ensures that VoD program is download to ACR

  o ACR controlled multicast realizes IPTV user authentication and authorization

  o ACR's large-scale multiplexing and switching capacity ensures 40mbps per user

  o Intelligent content distribution improves system's overall performance and effectiveness

  o support operation environment ensures system's manageable and operable

  5.9 Achievements of 3TNet

  o Tbps Transport:The third open DWDM transport system extensible to 80X40

  o Tbps switching:First metropolitan network based on ASON burst transport and multicast

  o Tbps routing:Merge of circuit and packet switching, the implementation of ACR

  o IPTV traffic:Real-time distributing metropolitan ASON and ACR which support IPTV

  o Scaled Test bed:Our Country's biggest IPTV(including HDTV) traffic test network - 20000 users with 40Mbps per user

  o Manufacturing Improvement:Lead network technology innovation and standard making,forming a basis of IPTV market

  5.10 3TNet’s Promotion

  o In 2004, Shanghai Municipality started eShanghai Project, which is a practical application of 3TNet

  n E-Entertainment

  o IPTV traffic in Zhabei District

  o Network games on 3TNet

  n E-Learning

  o Network education on 3TNet

  n E-Health – provide hospital and social service through 3tnet

  n E-Show – show shanghai economic result through 3tnet

  6 The Trend of Future Network and Traffic

  6.1 The Development Trend of Future Networks

  o Traffic Characteristic has an impact on network architecture evolution

  n Internet constructed by distributed pure IP routers – dying out

  n Hybrid switching architecture (connection oriented packet switching) – main direction

  n Solve end-to-end QoS problem - final target

  n From core network to edge network, optical communication and devices will change future networks

  n Gradually from IPv4 to IPv6

  n Development of broadband mobile access, ubiquitous application requirements

  n Considering security, controllable, management and economy

  6.2 Next Step of 3Tnet

  o The success of 3TNet at core network, edge network and stream media traffic will directly affect our country's new generation network and will put forward more research topics

  o To build large-scale real user oriented new generation network and test bed is our country's next 5 five year's plan, which is an opportunity to transcend network technology of developed countries

  o We will deploy network architecture, critical network devices, new traffic and provision mode on the test bed

  7 Conclusion

  o IPTV oriented large-scale concurrent media stream will be the major traffic in high speed network

  o IPTV calls for a new generation high speed network architecture

  o New generation high speed network foretells huge commercial opportunities and continuous technology innovation

  Author Biography:

   Mr. Wu Jiangxing, 52 years old, is an academician of China Academy of Engineering. He is President of China National Digital Switching System Engineering and Technological R&D Center and Chairman of the Supervisory Group for the Major Dedicated Projects of the High-performance Broad-band Information Network in China’s “863”Hi-tech Research and Development Program. Since 1998, he has been China’s member of the APEC Business Advisory Council. From 1992 on, he served respectively as a member and co-chair of the Communications Expert Group of China’s “863” Hi-tech Research and Development Program .

  




搜狗(www.sogou.com)搜索:“IPTV”,共找到 225,079 个相关网页.
页面功能 【我来说两句】【热点排行】【推荐】【字体: 】【打印】 【收藏】 【关闭
 
-- 给编辑写信


Copyright © 2005 Sohu.com Inc. All rights reserved. 搜狐公司 版权所有
相关链接
  • 中信杨可可探讨IPTV商业新模式的报告(06/06 16:30)
  • UTSTARCOM吴鹰“IPTV的快速发展和增值实现”(06/06 18:19)
  • 娱乐天天精选
    明星的化妆间中的走光
    明星的化妆间中的走光
    靠胸吃饭的众女星全解
    关之琳成长私密照曝光
    ·明星新闻-笔笔暗指春春壮阳|梁咏琪自剖分手真相
    ·章子怡中田英寿亲密看秀|张靓颖提起黄健翔就变脸
    ·娱乐社区- 看明星牙齿揭露明星另一面 夫妻吵架
    ·八位保养得面目全非的女明星 张靓颖走秀输给周迅
    ·我音我秀- 锵锵揭露假币骗局 CrazySoccer 卢正雨
    ·网友原创视频四部曲 过年了您该休息了 九曲黄河
    请发表您的看法
    用户: 匿名发出
    您要为您所发的言论的后果负责,故请各位遵纪守法并注意语言文明。
    留言:
    *经营许可证编号:京ICP00000008号
    *遵守《互联网电子公告服务管理规定》
    *遵守《全国人大常委会关于维护互联网安全的规定》


    搜狐商城
    化妆|春季彩妆5折争艳
    家居|06年最抢眼饰品
    音像|周杰伦:霍元甲D9