Access to the Broadcast Media: The Legislative Precedents

Application of the Fairness Doctrine in license renewal proceedings "has been far more effective than specific access rights in opining broadcasting to the views and participation of minority groups."     

一种FPGA中BRAM36k的设计方法

BRAM以阵列的方式排布于FPGA内部,是FPGA实现各种存储功能的主要部分。FPGA通过BRAM以及可编程逻辑资源给用户提供各种不同的存储资源。介绍了FPGA其中可编程存储模块BRAM36k的具体功能以及实现方法。该模块支持多种地址和数据位宽纵横比组合、多种读接口和写接口数据带宽转换,支持奇偶校验bit写入和读出。最后对模块的功能进行了功能级仿真验证,仿真结果符合预期设计目标。     

龙口广电宽带综合信息接入网的建设

根据龙口市宽带综合接入网的拓扑结构、传输体制和接入网技术，介绍网络建设与运营经验。     

西藏县级广电网络建设

光纤入户(FTTH)是广电网络发展的必然趋势,是广电网络开展数字电视服务和双向宽带视频及数据业务的理想解决方案.根据西藏具体的地理状况、人口分布特点和广电网络发展现状,同时结合当前网络建设的新技术,从西藏广电网络建设的技术路线出发,系统地介绍了西藏广电网络特别是县级网络的发展建设情况,为FTTH接入技术在广电网络的应用提供了一个新的案例.     

广电宽带互动电视接入技术

广电发展的潜力在于增值业务的开展,而增值业务的发展方向是宽带互动电视,解析5种广电宽带互动电视接入技术,其中ITIS是值得广电推广运用的系统方案.     

广电接入网双向改造的实践与思考

应对三网融合的挑战与机遇,广电网络定当率先进行接入网的双向改造,结合在广电双向网改一线的工作经验,对EPON+LAN、CMTS以及EoC等双向网改的接入技术进行探讨。     

广电城域接入网技术选择和实施建议

目前广电接入网建设与改造中技术方案的选择应考虑的问题具体包括：同轴入户还是光纤入户（ Cable or FTTH ）、DOCSIS或C-DOCSIS的选择、EPON＋EoC或EPON＋LAN的选择、高频EoC或低频EoC的选择、接入网光纤网络技术的选择---EPON或GPON、接入网光网络拓扑结构的选择---FT-TC/FTTZ或FTTB/FTTE,针对以上几点进行研究分析,并提出一些可供参考的意见。     

Randomized Broadcast Channel Access Algorithms for Ad Hoc Networks

The problem of broadcast channel access in single-hop and multihop ad hoc networks is considered. Two novel randomized and distributed channel access algorithms are developed and analyzed for single-hop and multihop networks, respectively. These algorithms are designed based on maximizing the worst-case channel efficiency, by optimizing some key parameters, including the backoff probability distribution and the slot length. The proposed algorithm for single-hop networks offers significantly higher throughput than the CSMA methods when the traffic load is heavy, while still achieving good performance when the load is light or medium. The proposed algorithm for multihop networks can flexibly adapt to the traffic load, and offers much better throughput performance than the existing broadcast scheduling algorithms in light or medium load.     

HFC Access Network Design for Switched Broadcast TV Services

The hybrid fiber coax (HFC) is a modern broadband access network, providing advanced interactive services such as Internet access, digital interactive television and cable telephony. The edge costs dominate the cost of launching new services, at the time of deployment (CapEx) as well as for maintenance (OpEx). Therefore next-generation edge devices aim at the convergence of these services and their platforms into a single multi-service infrastructure, thus sharing resources and bandwidth. The focus of this paper is on the HFC access network design for bandwidth-intensive TV services, bringing standard as well as switched broadcast technologies into play. Standard broadcast TV service deployments, offered through the digital video broadcast (DVB) platform, require low installation costs, but the bandwidth consumption increases linearly with the number of available TV channels, even for very unpopular channels. Switched broadcast TV channels, offered on the (Euro-) DOCSIS platform together with other interactive unicast services such as video on demand, are only streamed to a node on the HFC access network if they are requested locally, thus limiting bandwidth consumption for less popular channels. We present an access network design tool, based on an analytical TV traffic model, minimizing the installation cost on the edge devices and study the influence of the most important traffic and content parameters.     

基于PON的农村宽带接入方案研究

在分析农村地区地理环境及业务特点的基础上，阐述了应用PON技术解决农村接入问题的优势，提出了基于PON的3种组网万式，并对不同组网方式的优劣势及投资估算进行了比较。     

Random Signal Levels for Channel Access in Packet Broadcast Networks

In this paper, it is proposed to employ random multiple signal levels for channel access in packet broadcast networks. We present priority-free random access protocols that possess the advantage of capture effect. The presented schemes are applied to the slotted ALOHA, and the performance is analyzed based on a conservative capture model. Closed-form expressions for the system throughput are derived for a general two-signal level system and a generalm-signallevel system. It is shown that the maximum throughput for the twolevel system increases from 0.47 to 0.52 as the separation between the two levels increases. For them-level system, the maximum throughput increases from 0.52 to 0.66 asmincreases from three to infinity. Then a rotary-priority sure-capture random access scheme is presented, which can achieve perfect channel utilization. The time-delay characteristic and the throughput-delay tradeoff are analyzed for the simplest two-level system for which the higher level is double the lower level. The results compare favorably to those of the conventional slotted ALOHA system which employs a single signal level for packet transmission. A number of open problems are addressed.     

广电网络双向接入技术综述

用户接入技术对于宽带网来说具有非常重要的意义,广电双向网络的用户接入技术从初期的DOCSIS发展到EPON+EoC,乃至终极接入方式的光纤入户(FTTH).本文从广电网络双向接入技术的演进出发,系统介绍了包括基于EoC和FTTH的双向宽带接入技术.     

广电宽带城域网接入认证技术选择

介绍了接入认证选择原则和宽带城域网接入认证技术的3种常用方式,即PPPoE、Web、802.1x,分析了各自的优缺点,对3种常用的接入网方案进行了比较和推荐。     

新世纪广播电视接入网发展思考

新世纪已经来临 ,信息化浪潮正在冲击整个地球 ,朱总理在政府工作报告中指出 ,把高速宽带信息网络作为信息化发展的重点战略目标推进。新世纪具有信息高速公路“最后 1ｋｍ”之称的广播电视接入网将如何建设 ,怎样使我们的接入网成为“十五”规划中全国广播电视传输网络的一部分 ,这是我们网络工作者必须思考的问题。我市广播电视接入网 (ＭＡＮ城域网 )同全国各地广播电视接入网一样 ,始建于2 0世纪 80年代末期 ,经 10多年来的不断发展 ,已日趋完善 ,初具规模 ,已能传输较高质量的视频信息节目 ,已有相当数量的用户 ,基本能满足一般用户日…     

广电网络用户双向接入方案技术研究

数字电视得到广泛普及,开展数字电视增值业务是广电网络公司目前的迫切任务,增值业务是建立在双向网络基础上的．其中用户双向接入网络和设备部分一直是大家关注的重点,本文通过对不同的双向接入方案做了详细的对比分析,确定理想的接入方案。     

广播电台安全播出风险分析方法研究

结合广播电台网络化制播体系的特点、现状,主要分析风险评估理论与工程实践的结合点．研究如何将风险评估理论和方法应用到广播电台网络化制播体系的安全播出风险评估中。通过研究,实现风险评估理论的转化应用工作,为广播电台建立一套便于实施的风险评估模型,使风险评估的理论和方法在广播电台网络化制播体系的安全播出管理中能够得到真正的应用,帮助提高广播电台安全播出管理水平,为广播电台安全播出提出一个评估的依据和参考。     

贯彻落实科学发展观创新广播电视户户通的“如东模式”

经过5年的努力，如东建成了江苏省广播电视户户通先进县，上级领导对如东县贯彻落实科学发展观，扎实抓好农村广播电视工作给予了充分肯定，并称其为“如东模式”。介绍如东县广播电视户户通的几点做法和经验，供广电同行借鉴。     

广电接入网双向化改造策略研究

本文对广电接入网双向化改造三种主流技术方案进行比较研究．分析双向改造过程中遇到的难点．提出广播电视网络提升至电信级网络、面向三网融合及建设下一代网络的建设策略。     

远洋船舶公共广播系统应用与改进

介绍了公共广播系统在远洋船舶中的应用，针对现代化船舶通信系统的发展与广播系统的现状，根据远洋船舶广播应用实践，提出了基于计算机控制的自动船舶公共广播系统，对其功能拓展的方案及优化改进措施进行了讨论。     

The Pulse Duration Modulator: A New Method of High-Level Modulation in Broadcast Transmitters

A new approach for obtaining the audio power required for high-level plate modulation of AM broadcast transmitters is described. The advantages of this system are lower initial cost, broader frequency response, lower distortion, transmitter output adjustable from zero to full output, lower power consumption, fewer amplifier tubes, and lower operating cost.