有条件接收技术在数字电视终端上的实现研究
文献类型：学位论文
| 作者 | 陈君 |
| 学位类别 | 博士 |
| 答辩日期 | 2004 |
| 授予单位 | 中国科学院声学研究所 |
| 授予地点 | 中国科学院声学研究所 |
| 关键词 | 机顶盒 有条件接收 同密 多密 嵌入式多CA体系 网络直播电视 |
| 中文摘要 | 为了保证数字电视技术的正常发展，保护各方面的利益，运营商及其用户之间需建立一种经济关系，即“有偿服务体系”。有条件接收系统（Conditional AccesS System，CAS），其基本目的是通过对用户的授权控制和管理，实现数字广播系统的有偿服务，在为运营商带来经济上回报的同时，也能为用户提供更多、更高质量的服务内容，它是实现付费电视、交互电视的关键技术。现阶段，由于各有条件接收系统在加密体系和智能卡通信接口上没有一个统一的标准，使得有条件接收系统与作为数字电视终端接收设备的机顶盒之间的接口规范成为影响数字电视产业发展的关键问题。如何使一个机顶盒能够接收多路由不同CAS加密的节目，是业内探讨的一个热点。本文首先分析了目前有条件接收技术、机顶盒发展技术和国内广电系统运营结构的现状及存在的问题，之后结合DVB有条件接收技术的相关标准和规范，详细介绍了有条件接收系统的原理和工作流程。在此基础上，探讨了在一个机顶盒上同时支持多个CA系统可采取的几种解决方案。基于公共接口的DVB多密技术提供了一个非常开放的系统实现方式，实现了机顶盒软硬件与CA系统的完全分离与独立，从而使机顶盒可以支持任意的CA系统，而且对于未来发展的各种CA系统具有很强的兼容性。木文对多密技术进行了深入的研究，设计并实现了支持多密公共接口的机顶盒。本文还提出了一种新的解决方法，称作“嵌入式多CA体系”。基本思想是在一个机顶盒中集成多个CAS软件模块，并通过与其各自相关的智能卡的协同工作，来实现一个机顶盒对多个CAS功能的支持。该方法通过规划和设计统一的CAS调度机制，实现多个CAS的共存，并能根据当前节目码流的实际加扰性质和用户所具备的解扰条件来自动切换各CAS的工作状态。论文最后还简单介绍了有条件接收技术在基于IP互联网的直播电视系统中的新应用，并探讨了接收端设备的实现及其安全性能改善方法。 |
| 英文摘要 | To redound to the fast development of the digital television industry and protect the profit of all participators, the service operators and their subscribers need to set up a kind of economic relationship, i.e. pay-TV. The essential intention of Conditional Access System (CAS) is to achieve pay-TV of the digital broadcast system by means of subscriber management and authorization control. So CAS is the key technology to realize the pay-TV and interact-TV. CAS can bring profits to the service operators and thus the service operators will provide more kinds of contents with better qualities. Nowadays, because of the absence of a uniform standard for CAS on the encryption system and the communication interface with smartcard, the interface specification between CAS and the decoder, i.e. the set-top-box (STB) as the terminal receive equipment in digital television system becomes the key point that is affecting the development of digital television industry. How to receive multi-programs, each of that is controlled by deferent CAS, within one set-top-box is a hotspot problem. This thesis firstly analyses status quo and the existent problems of the conditional access system, set-top-box technology and the multi-level structure for management and operation in broadcasting and television industry. After that, the principle and mechanisms of conditional access system with the related Digital Video Broadcasting (DVB) standards and specifications are described. Base on that, we discuss several method which can support multi-CAS in one single STB. One solution is the DVB multicrypt technique that is based on the common interface. The DVB multicrypt solution allows broadcasters and subscribers to change CA system without replacing the set-top-box. It is really an open and secure technique and can compatibale with any kind of future CA system, A design and implementation of DVB common interface within our decoder based on LSI SC2005 is described in this paper. This thesis also presents a new method called "embedded multi-CA system". The main idea is to receive programs scrambled by different CAS by integrating multi-CAS modules in one decoder and cooperating with multi smartcards. This method can make multi-CAS coexist by uniform the CAS scheduler which can control the working status of each CAS according to the real encryption style of the current program and the decryption condition of the subscriber. Finally, this thesis briefly introduces a new application of the conditional access technology in the IP based intemet-TV system and discusses the method to improve the security performance of the receiver. |
| 语种 | 中文 |
| 公开日期 | 2011-05-07 |
| 页码 | 102 |
| 源URL | [http://159.226.59.140/handle/311008/840]  |
| 专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
| 推荐引用方式 GB/T 7714 | 陈君. 有条件接收技术在数字电视终端上的实现研究[D]. 中国科学院声学研究所. 中国科学院声学研究所. 2004. |
入库方式： OAI收割
来源：声学研究所
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