基于ATMux数字电视平台系统三方CA同密的实现

本文介绍盐城ATMux数字电视平台系统及基于该系统的CA建设方案,从运营的角度出发提出基于ATM交换技术实施多CA同密的概念,并获得实施成功。     

CA系统的同密及多密技术

目前,全球在数字电视的CA(Conditional Access:条件接收)技术方面,流行着两大标准,即美国的ATSC(Advanced Television Systems Ccommittee:先进电视系统委员会)标准和欧洲的DVB(Digital Video Broadcasting:数字视频广播)标准。前者由于种种原因,应用案例相对较少。后者由于其标准的开放性、公开性,适用范围较为广泛,得到了业内人士的好评,应用案例相对较多。现就当前较为流行、应用案例较多的DVB平台中CA系统的SC(Simul Crypt:同密)和MC(Multi Crypt:多密)标准,以及由SCTE(Society of Cable Telecommunication Engineers:有线电视通信工程师协会[美国])组织推荐的基于DVB标准的POD(Point of Deploy:配置点)和Open CAS(开放的条件接收系统)标准进行论述。     

浅析数字电视CA系统同密与多密技术

本文介绍了同密与多密技术的工作机制,分析了同密与多密技术的优缺点,并解释了同密CA系统在我国数字电视整体转换中被广泛应用的原因。     

同密CA系统快速清流输出一例

1引言CA(条件接收)用于数字电视广播系统的用户认证、授权和节目加扰,以便从用户处收取费用和阻止用户收看那些未经授权的付费频道。同密是前端使用两个以上的CA,每个CA使用不同的加密系统来处理CW,产生不同的ECM和EMM,但加扰器和CW是共享的。南通有线电视网络使用爱迪德Plsys系统与中视联ChinaCryptDVB条件接收系统同密,采用哈雷THESYS网管和复用器。     

利用Sniffer技术进行CAS同密接口测试原理与实现

本文首先介绍DVB同密的概念以及同密接口重要性,简单地介绍了同密的接口,从同密接口实现的机制来研究怎样实现对同密接口的测试：用Sniffer机制窃听同密接口设备之间的通讯IP包,通过IP协议、TCP／UDP协议、同密接口协议以及TLV编码协议的解析和重组,真实重现了同密接口通讯的消息,同时验证被测试设备同密接口是否符合标准和复用器是否正确地把通过同密接口接收到的EMM和ECM复用到传输流中。     

数码视讯加扰器与多家厂商CA同密成功

数码视讯CHINIC10K571型DVB独立数字加扰器采用国际最新技术,符合国际DVB3.0标准,可兼容多个条件接收系统(CA),支持同密(SimulCrypt),已经与数码视讯StreamGuardCAS、永新同方、算通、中视联CAS、法国电信VacessCAS、NDS、爱迪德成功集成,并且在中央台顺利完成与爱迪德、NDS、永新同方三家CA系统的连通,以及实现永新同方CAS与算通CAS、天柏CAS在烟台的同密。数码视讯CHINIC10K571型DVB独立数字加扰器可对多达32个service(并可根据需求任意扩展)提供不同的CW,并且可以分别对音频、视频及数据实施单独或者任意组合加…     

浅谈同密

同密是DVB标准定义的内容。国外用同密作为条件接收系统替换或升级的过渡方案,而国内多将同密作为长期的运营手段。进行多家条件接收系统的同密可能会带来系统安全性下降、集成难度增加、系统性能可能降低、维护工作量增加等问题。     

论DVB条件接收系统的同密及多密标准

目前．全球在数字电视的CA技术方面．流行着两大标准．即美国的ATSC标准和欧洲的DVB标准。前者由于种种原因，应用案例相对较少。后者由于其标准的开放性、公开性．适用范围较为广泛，得到了业内人士的好评，应用案例相对较多。现就当前较为流行、应用案例较多的DVB平台中CA系统的同密和多密标准．以及由SCTE组织推荐的基于DVB标准的POD和Open CAS标准进行论述。     

湖州市数字电视平台二级CA及多家CA同密技术的运用

本文主要是以湖州市数字电视平台搭建为例,叙述了湖州数字电视平台CA系统和央视数字电视平台CA系统在二级CA具体管理功能的实现,以及多家CA系统同密技术在湖州数字电视平台上的实际运用。     

如何实现动态网络安全

本文为提高网络的安全性做了一些探索，介绍了一个基于动态安全管理的网络安全体系结构。通过对网络的风险进行分析、量化、建立安全模型、提供总体安全解决方案，应用安全技术与产品，建立合理的安全反应机制，实现一个可实施、可控制管理、全面的动态安全体系。     

如何实现网络动态安全

网络的安全问题一直是困扰业界的一个问题。尤其对金融、证券、电信、大型ISP等信息化步伐较早、业务和网络应用较复杂的行业,网络安全与否很大程度上影响着网上业务的可行性和可靠性。银行正在开展家庭银行、手机银行、网络银行等新金融业务,证券公司也在开通网上交易、手机炒股、存折炒股等新交易方式,有些券商还在计划建立开放式营业部。网络在这些行业的新应用都极大地扩展了业务的应用范围,也方便了用户。但是,随之而来的网络系统的安全问题也越来越突出。     

可移植的TigerSHARC DSP应用设计

为了提高TigerSHARC DSP软硬件设计的灵活性,分析并应用了Visual DSP kernel(VDK)RTOS下DSP间消息通讯的软件框架结构.用统一建模语言UML描述了DSP软件应用层和硬件抽象层(HAL)的逻辑结构和相互关系.以ADSP-TS101DSP的Link口为例,详细说明了基于框架的DSP软件设计与实现方法.实例表明,分层的DSP软件架构模式使应用层的软件实现与DSP间的物理连接无关.     

Software Maintainability - What It Means and How to Achieve It

The terms reliability and maintainability are often misunderstood in the software field since software does not `break' or `wear out' in the physical sense; it either works in a given environment or it does not. This means that the program is either right or wrong in the environment. However, it does not follow that a program that is right is reliable or maintainable. For the purposes of this paper a program is maintainable if it meets the following two conditions: ? There is a high probability of determining the cause of a problem in a timely manner the first time it occurs, and ? There is a high probability of being able to modify the program without causing an error in some other part of the program. There are three important topics in developing a program which fulfills the above criteria: documentation, standards, and system architecture. This paper discusses the third topic since it is the real key to the development of maintainable software. A particular architecture of structured modular design using controlled communication between modules is presented together with its relationship to maintainability and reliability. The benefits of this approach are: ? High isolation between modules. ? Communication visibility and monitoring. ? Error location. ? Overload control. ? Simplified control program. ? Transparency to multicomputer configurations. A method is presented for calculating maintainability parameters related to this architecture, and examples of these calculations are given and interpreted.     

如何建设农村广播电视IPTV实现三网融合

介绍在三网融合的今天,如何使我国农村广播电视尽快建立一张适应农村本地需要的IPTV网络电视台,为＂统筹城乡发展＂广播电视当好先行军,并介绍建立农村IPTV网络电视台的具体技术和实施方法。     

On the Largest Possible Mobility of Molecular Semiconductors and How to Achieve It

A large database of known molecular semiconductors is used to define a plausible physical limit to the charge carrier mobility achievable within this materials class. From a detailed study of the desirable properties in a large dataset, it is possible to establish whether such properties can be optimized independently and what would be a reasonably achievable optimum for each of them. All relevant parameters are computed from a set of almost five thousand known molecular semiconductors, finding that the best known materials are not ideal with respect to all properties. These parameters in decreasing order of importance are the molecular area, the nonlocal electron–phonon coupling, the 2D nature of transport, the local electron–phonon coupling, and the highest transfer integral. It is also found that the key properties related to the charge transport are either uncorrelated or “constructively” correlated (i.e., they improve together) concluding that a tenfold increase in mobility is within reach in a statistical sense, on the basis of the available data. It is demonstrated that high throughput screenings, when coupled with physical models of transport produce both specific target materials and a more general physical understanding of the materials space.     

How to Achieve Perfect Simulation and a Complete Problem for Non-interactive Perfect Zero-Knowledge

This paper studies perfect zero-knowledge proofs. Such proofs do not allow any simulation errors, and therefore techniques from the study of statistical zero-knowledge (where a small error is allowed) do not apply to them. We introduce a new error shifting technique for building perfect simulators. Using this technique we give the first complete problem for the class of problems admitting non-interactive perfect zero-knowledge (NIPZK) proofs, a hard problem for the class of problems admitting public-coin PZK proofs, and other applications.     

广播电台融媒体编辑如何做好节目编排

随着网络技术的不断发展,融媒体作为一种新型的信息平台已经开始应用于广播电台,实现了融合发展。在这样的大背景下,广播电台编辑如何做好节目编排工作就成为一个重要的课题。就目前来看,广播电台编辑在节目编排工作中还存在着一定问题,这些问题在很大程度上阻碍了工作的开展。着重论述了融媒体时代下,广播电台编辑编排工作中存在的具体问题以及提升节目编排质量的相应措施。     

Orientation Diffusion or How to Comb a Porcupine

This paper addresses the problem of feature enhancement in noisy images, when the feature is known to be constrained to a manifold. As an example, we approach the orientation denoising problem via the geometric Beltrami framework for image processing. The feature (orientation) field is represented accordingly as the embedding of a two dimensional surface in the spatial-feature manifold. The resulted Beltrami flow is a selective smoothing process that respects the feature constraint. Orientation diffusion is treated as a canonical example where the feature (orientation in this case) space is the unit circle S¹. Applications to color analysis are discussed and numerical experiments demonstrate again the power of the Beltrami framework for nontrivial geometries in image processing.     

DVB同密、多密技术与POD技术的比较分析

条件接收系统(CAS)是数字电视的关键技术之一.介绍并比较分析目前国际上的两种实现CAS的技术标准:DVB同密、多密技术与POD技术.