基于NGOD的SDV系统会话管理服务器会话处理方案

介绍了一种基于NGOD架构的交换式数字广播电视（SDV）系统架构和其中会话管理服务器的设计实现方案。通过交换式的提供广播电视数据,可以有效的节省广播电视网HFC段带宽,同时提供用户更多可收看节目频道以及更好的用户体验。     

Hybrid fiber/coax in the public telecommunications infrastructure

The benefits of the hybrid fiber/coax (HFC) architecture for the delivery of interactive broadband services have been widely discussed in the past few years. The cable television industry began deployment of this infrastructure in 1989 to support the broadcast video business. Recently, domestic telephone companies have looked at various degrees of HFC implementation, ranging from the delivery of broadcast video only to full telephony integration. The article looks at the HFC network evolution from a broadcast, non-essential, isolated architecture to a robust, interactive, broadband element within the public telecommunications fabric. Regional networks, interface to the public network and network management systems are a few of the significant issues with respect to the viability of HFC as the access layer to the “information superhighway.” If the HFC platform proves viable, telephone companies will adapt it to meet their needs in a fully integrated system     

Design of Optical Content Distribution Networks for Video on Demand Services

This paper presents the design of optical content distribution networks for video on demand (VoD) services. The proposed Ethernet-based WDM network architecture is decentralized and consists of independent regional ring networks with locally deployed video servers. Based on an Integer Linear Programming (ILP) model, a network design tool, minimizing the total installation cost for optical network equipment on the metro and the Hybrid Fiber Coax (HFC) access network, has been developed. Unicast as well as broadcast VoD services are taken into account. The influence of different parameters in our traffic and content models on the network design is studied.     

吴江广电EPON＋EOC双向网络改造实践

吴江广电2009年进行原有HFC网络双向改造,采用EPON＋EOC方式,利用现有接入用户的有线电视同轴电缆,改造后的网络同时支持模拟电视、数字电视、互动电视、数据业务和传统TDM业务,满足全业务运营接入网的目标要求,在同一个平台上提供电视、数据、语音和视频应用,信号开通以来,用户反映情况良好,为吴江广电全业务开展打下良好基础。     

Alternative technologies and delivery systems for broadband ISDNaccess

Switched on-demand video is expected to become a major consumer of bandwidth. Two-way video offers televisting, tele-education, and telecommuting services, which together could represent a further substantial bandwidth demand. High-speed data services to provide the fiber distributed data interface (FDDI) between locations, or even operate a computer-aided design (CAD) terminal remotely from its local area network (LAN), are likely new applications for broadband integrated services digital networks (B-ISDN). The video quality evolution and digital modulation techniques that are making broadband digital delivery of TV signals possible are reviewed. Cable TV B-ISDN delivery, short twisted pair B-ISDN delivery, and TV broadcast digital delivery are discussed     

Challenges and opportunities of delivering IP-based residential television services

This article describes the main challenges of implementing an end-to-end architecture for delivery of high-quality, IP-based residential TV services to residential customers. The IP-based approach can be implemented with an IP multicast overlay network with traditional routers or use IP-multicast-aware ATM switching systems. Both approaches use IP multicast to transport MPEG-2 broadcast video and can work on any access architecture, especially on copper-based architectures (xDSL) such as ASDL and VDSL. The main challenges met while implementing the IP-based architecture are competitive positioning relative to traditional CATV architectures, overall architecture, head-end architecture and quality issues, traffic engineering for stringent QoS requirements, IP multicast requirements, and business case considerations. The IP-based approach described leverages Internet technology advancements and capitalizes on the impacts of Internet on interactive entertainment. Video channel manipulation at the head-end is dependent on access bandwidth and affects video quality. Video traffic management to meet stringent QoS requirements is challenging at the IP layer. High-capacity, responsive IP multicasting is essential to achieving high service quality. Cost-effective IP multicasting is a critical component of the business case.     

论基于HFC网络结构的演变

随着业务需求的增长,要求网络带宽越来越宽。有线电视HFC网络正在急速演变,其同轴电缆部分将逐步缩短,使其有利于语音、数据和视频信息的综合传输。交互电视、VOD、IP应用正在被人们看好,为实现用户的高比特率双向传送,HFC网络必须改造成光纤到大楼、光纤到家庭的结构。     

MLAP: a MAC level access protocol for the HFC 802.14 network

Interactive residential broadband/multimedia services are expected to be the next main event in the cyberspace experience. The large excess bandwidth (well over 300 MHz) available in today's cable TV (CATV) hybrid fiber/coaxial (HFC) plants is an ideal candidate to provide the underlying communications infrastructure for interactive digital services to the home; cable operators that have not yet upgraded their all-coaxial plants to HFC are quickly moving in this direction. MLAP is a flexible ATM-friendly MAC protocol that is capable of supporting various types of traffic with diverse quality-of-service requirements. We introduce a very versatile MAC protocol for the HFC 802.14 network. MLAP can provide integrated broadband services to the home, internetwork easily with ATM wide area networks, support QoS constraints for various types of traffic, and operate over a variety of physical layer protocols. Our presentation is only an extended summary of our medium-sharing protocol proposal to the IEEE 802.14 WG. We consider only error-free system operation. MLAP provides for the use of timers for the recovery of error situations in the network. MLAP is also supported by a management suite of protocols for management of the overall system     

The dawn of digital TV

The end of analog TV is at hand. Governments are setting firm dates and planning for the new broadcast TV. Although analog TV is being shutdown, it is observed that changing to digital TV costs much higher mainly because of its convenience in connectivity, crisp quality images and digital sounds. In the end, though, consumers are winners, with new and improved services available. They have access to HDTV's great pictures and sound. Thy have uniformly high-quality reception anywhere in a broadcast area, and additional services includes some within traditional broadcast channels but even more coming in the auctioned broadcast spectrum.     

浅谈大庆高清互动电视平台建设

从组网结构、平台构架优势和建设规模、组网需求等方面简述了大庆市基于HFC+IPQAM方式构建高清数字互动电视平台的系统设计,并分析了互动平台交互网络试点方案和互动平台交互网络与原CM网络的兼容方案,最后介绍了试点小区数字电视双向互动网络改造情况。该平台建设能够促进综合业务提供能力的提升,从而为运营商转变经营思路,实现战略转型提供了技术支持。     

基于DVB-C有线数字电视平台的应急广播系统

介绍了基于DVB-C有线数字电视平台的应急广播系统,依托现有有线数字电视播控与传输平台,应急广播指令与音频信号复用到数字电视播控平台.利用有线电视共缆传输,终端设备的技术实现与数字电视机顶盒基本一致.以全新的理念全面实现了音频/文字信息数字化、播控自动化、管理智能化、扩展自由化,与现有HFC网络完全融合,是广电运营商建设应急广播系统的理想的解决方案.     

广电网络业务发展的分析

以促进广电网络发展为纲,分析广电主要的3项增值业务:付费频道,高清互动,宽带业务。从实际出发,分析现状并为其正确定位,对其发展方向及业务增长方式题出建议,指出广电未来以电视业务宽带业务为主线的盈利格局。     

基于HFC的VOD系统设计

针对目前的HFC的频带资源被大量闲置的问题,文章设计了一套基于HFC的VOD系统,此系统通过IP/QAM设备,将千兆网络带宽划分为24个8MHz的频道,从而实现通过HFC实施支持交互式与广播式等多种多媒体通信应用。文章介绍了基于HFC网络的VOD系统设计与实现方案。     

IPTV--三网融合的开端

IPTV与目前的3个运营网（有线电视网、Internet和电信网）及其业务直接相关。但不同运营商对IPTV业务有不同定位。电信运营商认为IPTV业务体现于电视节目在IP网中的组织和传送形式，有线电视网络运营商认为IPTV业务是利用有线电视网来提供数字电视节目和电视节目以外的信息服务。由于IPTV业务分为广播业务和交互型业务两大类，支撑这两类业务的承载网也相应地分别采用单向广播网和双向交互网，因而在承载网层很难融合。融合工作将在业务层发生，即充分利用已经存在的两个承载网来经济、高效地发展业务。IPTV中既拥有广播型业务，又拥有组播型业务，还拥有交互型业务，将是三网融合的开端。     

永川双向网络建设与多业务的开展

永川市广电根据自身情况与现有网络状况,通过科学地考察与详细调研,本着安全可靠、技术先进、可扩展性的原则,进行了永川有线电视的双向HFC网络改造与建设,同时在双向网络基础上开展了多功能增值业务。重点阐述了互动电视业务的技术特点与业务功能,视频业务的双向性给广电带来了市场的竞争力与可观的经济收益。     

Fiber-to-the-home services based on wavelength-division-multiplexing passive optical network

It is anticipated that more than 75 Mb/s per subscriber is required for the convergence service such as triple-play service (TPS). Among several types of high-speed access network technologies, wavelength-division-multiplexing passive optical network (WDM-PON) is the most favorable for the required bandwidth in the near future. Furthermore, WDM technologies, such as athermal arrayed-waveguide grating (AWG) and low-cost light source, have matured enough to be applied in the access network. In this paper, the authors propose and implement a WDM-PON system as a platform for TPS. The system employs an amplified spontaneous emission (ASE)-injected Fabry-Pe/spl acute/rot laser diode scheme. It has 32 channels of 125 Mb/s and adopts Ethernet as Layer 2. Multicast and virtual local area network features are used for the integration of services such as Internet protocol high-definition broadcast, voice-over Internet protocol, video on demand, and video telephone. The services were demonstrated using the WDM-PON system.     

An on-demand TV service architecture for networked home appliances

The recent advent of networked home appliances has enabled enhanced on-demand multimedia services to be feasible. Especially, personal video recorders have made it more convenient to manage broadcast TV programs at home by storing them on their own disks. However, standalone PVRs have limitations on availability of TV programs due to limited reception channel and storage capacity. Networked PVR services can get over these limitations by storing all broadcast TV programs in remote storage systems that servers provide. Thus, these networked PVR services can have several advantages over standalone PVRs in terms of cost and availability. In this article we therefore propose an on-demand TV service architecture for networked PVRs to reduce response times to interactive operations and save network bandwidth. Finally, we show from simulation results that our proposed architecture both decreases the number of programs whose initial time-shifting operations are delayed and increases the hit ratio in cache servers significantly.     

面向高流量家宽业务的接入网演进策略研究

随着高清网络电视、3D视频等新兴业务的发展,用户对接入带宽的需求越来越高。针对高流量业务对接入网的需求变化,本文分析了现网存在的问题,测算了不同场景下接入网的承载能力,提出应对宽带提速的接入网络演进策略：OLT下行策略和OLT上联部署策略。本文所提策略能够有效指导运营商在面对用户流量高增长的形势下及时调整接入网络结构,为用户提供更好的网络体验。     

Improved priority access, bandwidth allocation and traffic scheduling for DOCSIS cable networks

The Data Over Cable Service Interface Specifications (DOCSIS) is intended to support IP flows over HFC (hybrid fiber/coax) networks with significantly higher data rates than analog modems and Integrated Service Digital Network (ISDN) links for high quality audio, video and interactive services. To support quality-of-service (QoS) for such applications, it is important for HFC networks to provide effective media access and traffic scheduling mechanisms. In this paper, we first present a multilevel priority collision resolution scheme with adaptive contention window adjustment. The proposed collision resolution scheme separates and resolves collisions for different traffic priority classes (such as delay-sensitive and best effort streams), thus achieving the capability for preemptive priorities. Second, a novel MAC (media access control) scheduling mechanism and a new bandwidth allocation scheme are proposed to support multimedia traffic over DOCSIS-compliant cable networks. It is shown through simulation results that throughput and delay performance have been improved for the transmission of real-time VBR (variable bit rate) traffic as compared to current DOCSIS specifications.     

基于HFC的宽带接入网关键技术

随着通信的发展和“信息高速公路”概念的提出,网络运营商越来越倾向集视频、话音、数据于一体的宽带综合业务,如今世界各国相继开发了基于现有铜缆的接入网技术高比特率数字用户环路(HDSL)和不对称数字用户环路(ADSL)、基于光缆接入技术的光接入网(OAN)、混合光纤同轴电缆(HFC)网络以及无线接入技术等宽带用户接入网技术,文章详细分析了HFC宽带接入网的网络结构及其关键技术。