基于数字电视多媒体消息增值业务系统TVPP协议研究

是以TVMMS(数字电视多媒体业务增值系统)系统为基础,在分析系统业务和工作流程的基础上,较全面提出数字电视多媒体业务增值系统各种传输机制,文章的重点就是提出适合TVMMS系统的TVPP(数字电视点对点协议),最后介绍使用TVPP终端接入服务器过程和VASP接入流程。     

基于数字电视网络可视电话的设计与实现

介绍了一种基于数字电视网络可视电话的原理和实现方案.利用数字电视点对点协议和SIP协议,完成了通信双方实时的语音和视频信息的交互.具体介绍了整个系统基于数字电视点对点协议(TVPP)所采取的框架结构,最后讨论了系统实现的关键技术和设计方案.     

有线数字电视广播技术浅析

本从有线数字电视广播(DVB—C)系统的数字电视信号源的前端处理、数字电视信号在HFC宽带网中的传输以及DVB—C数字电视节目的接收等方面。对有线数字电视广播技术进行了深入浅出的分析。     

基于CF卡的数字电视接收端存储系统的硬件设计

为了符合数字电视的发展和人们对数字电视功能越来越多的要求,提出了把数字电视接收端输出的TS(传输流)存储在CF(标准闪存)卡中,利用读写控制模块控制TS在CF中的存储和读取,从而实现对数字电视节目的存储和回放功能。给出了系统框架和控制模块内部结构,着重阐述了系统结构模块功能和模块的Verilog设计,给出了系统的仿真结果,具有一定的实用价值。     

基于B／S架构的数字电视监测系统的分析与设计

随着数字电视技术的不断发展以及我们国家数字电视工程的推广,对以数字电视信号为监测目标的数字电视监测系统的研究和设计显得十分必要。数字电视监测系统的应用实现了对数字电视信号动态、实时、全方位的监控。文章介绍了数字电视技术的相关特点和优势．以及广播电视监测系统的发展过程,给出了基于B／S架构的数字电视监测系统的设计结构．介绍了架构中各个子系统的功能。在此基础上分析了对数字电视信号质量监测的具体内容。     

第二讲 有线数字电视前端播出系统（上）

一、CADTV(有线数字电视)前端播出系统概述。数字电视广播不仅是电视广播信号的数字化，而且提供一种全新的业务平台。数字电视系统是一个规模巨大的系统工程，数字电视广播不仅能提高节目传送能力，还能够传送模拟电视广播所不能传送的其他业务。CADTV(Cable Digital TeleVision：有线数字电视)只是数字电视系统的一个部分，CADTV前端包括数字电视信源、中间件、NVOD(准视频点播)、编码复用、CAS(Conditional Access System：条件接收系统)、SMS(Subscriber Management System：用户管理系统)、调制设备及网络管理设备。     

中国地面数字电视广播信道编码调制芯片介绍

根据中国地面数字电视传输标准(GB20600-2006),分析了我国地面数字电视广播(DTTB)系统的技术特点,介绍了其系统结构,并在此基础上实现了符合国标全模武的中国地面数字电视广播系统的专用集成电路.     

浅谈有线数字电视用户端故障的维修

嘉兴有线数字电视平台于2003年3月建成，并投入试运行，同年7月数字电视系统正式投入商业运行。目前我市共传送80多套数字电视节目，数字电视用户发展了4000多户。数字电视系统建成后，最薄弱的环节就是技术服务和维护工作，必须经常向用户宣传如何正确使用机顶盒。有线数字电视维护管理工作已经引起了人们的重视。通过一年多来的维修实践，使我们对有线数字电视用户端逐渐摸索到一些常见故障的维修经验。现将数字电视用户端故障实例作一简单的分析，并提出解决故障的方法，供同行们参考。     

地面数字电视广播条件接收的应用

按照国家广电总局制定的十五规划,2015年停止模拟广播电视的播出,普及数字电视。数字电视系统从传输方式上看大致分为有线数字电视、卫星数字电视和地面数字电视系统。有线数字电视系统经几年发展相对成熟,已形成相对完善的运营模式和发展思路．但整套系统的推广费用较高;卫星数字电视受技术与管理因素的限制．大范围商用有难度;     

地面数字电视发展概况

按信号传输方式分类．数字电视可以分为地面无线传输(地面数字电视)。卫星传输(卫星数字电视)、有线传输(有线数字电视)三类。与有线和卫星传输方式相比，在信道状况和应用需求等方面．地面传输方式更为复杂。在地面数字电视传输系统方案的选择上争议最大。然而．数字电视地面广播的推广和产业化将带来新的经济增长点．世界各国都非常重视其标准的制定及相关的知识产权问题。     

基于SIP和TVPP协议的短信网关的研究和实现

对短信网关的功能结构以及会话发起协议（SIP）、电视对等通信协议（TVPP）进行了研究,在实现了两协议的基础上,进一步给出了实现短信网关接口的简单模型,并对该模型的体系结构等进行了分析。     

Peer group image enhancement

Peer group image processing identifies a "peer group" for each pixel and then replaces the pixel intensity with the average over the peer group. Two parameters provide direct control over which image features are selectively enhanced: area (number of pixels in the feature) and window diameter (window size needed to enclose the feature). A discussion is given of how these parameters determine which features in the image are smoothed or preserved. We show that the Fisher discriminant can be used to automatically adjust the peer group averaging (PGA) parameters at each point in the image. This local parameter selection allows smoothing over uniform regions while preserving features like corners and edges. This adaptive procedure extends to multilevel and color forms of PGA. Comparisons are made with a variety of standard filtering techniques and an analysis is given of computational complexity and convergence issues.     

A Fuzzy Logic-Based Method for Replica Placement in the Peer to Peer Cloud Using an Optimization Algorithm

The Peer to Peer-Cloud (P2P-Cloud) is a suitable alternative to distributed cloud-based or peer-to-peer (P2P)-based content on a large scale. The P2P-Cloud is used in many applications such as IPTV, Video-On-Demand, and so on. In the P2P-Cloud network, overload is a common problem during overcrowds. If a node receives many requests simultaneously, the node may not be able to respond quickly to user requests, and this access latency in P2P-Cloud networks is a major problem for their users. The replication method in P2P-Cloud environments reduces the time to access and uses network bandwidth by making multiple data copies in diverse locations. The replication improves access to the information and increases the reliability of the system. The data replication's main problem is identifying the best possible placement of replica data nodes based on user requests for data access time and an NP-hard optimization problem. This paper proposes a new replica replacement to improve average access time and replica cost using fuzzy logic and Ant Colony Optimization algorithm. Ants can find the shortest path to discover the optimal node to place the duplicate file with the least access time latency. The fuzzy module evaluates the historical information of each node to analyze the pheromone value per iteration. The fuzzy membership function is also used to determine each node's degree based on the four characteristics. The simulation results showed that the access time and replica cost are improved compared to other replica replacement algorithms.

     

基于对等体组的Web服务发现机制

针对目前Web服务发现中存在的问题，对服务发现中服务匹配比较的方法进行改进．提出了二次检索的方法，并将P2P的网络架构引入到Web服务发现中来，提出基于Web服务和对等体组（Peer Group）的Web服务发现系统，给出了系统结构框架并通过实验证明方法的可行性和有效性。另外，对UDDI注册中心进行了一些改进．使之更便于适应改进后的Web服务发现架构。     

Using topology information for quality‐aware Peer‐to‐Peer multilayer video streaming

Due to increasing bandwidth capacities, the Internet has become a viable transport medium for a (live) video. Often, delivery of video streams relies on the client–server paradigm and therefore exhibits limited scalability. The Peer‐to‐Peer (P2P) network model is an attractive and scalable candidate to stream video content to end users. However, these P2P frameworks typically operate in a network agnostic mode. Introducing network topology information into these P2P frameworks offers opportunities to enhance the performance. In this paper, we introduce a model to include network information when streaming a (multilayered) video in P2P frameworks. An important metric for video stream providers is the content quality perceived by end users. The optimization studied here aims at maximizing the number of users receiving a high quality video. The paper addresses the optimization problem seen from the stream provider's viewpoint, having access to network topology information. An exact optimization approach is presented for benchmarking purposes and a heuristic approach to cope with realistic network sizes. In addition, we present an approach to decide the deployment location of peering functionality. The results show that our strategy significantly decreases the fraction of destinations receiving only the base layer, and by introducing extra peering functionality, network capacities are used more efficiently. Copyright © 2015 John Wiley & Sons, Ltd.     

地面数字电视广播系统的研究

本文主要介绍了地面数字电视广播（Digital Television Terrestrial Broadcasting,DTTB）系统,在介绍国外现有的DTIB传输标准的基础上说明清华大学数字电视传输技术研发中心提出的DMB—T（Terrestrial Digital Multi—media／Television Broadcasting）标准。DMB—T系统采用了时域同步正交频分复用（TDS-OFDM）的多载波调制方式,适用于具有多径干扰和多普勒频移的地面数字电视广播传输信道。通过比较,DMB—T具有新的关键技术和优越的性能。     

在广电工程中实施项目管理系统

项目管理是一套行之有效的工程管理方法。针对传统广电工程管理的不足,利用JAVA＋MYSQL技术,开发一套适合广电工程的项目管理系统,结合原有办公管理系统,有效利用互联网,实现管理系统的网络化,从而实现对工程的实时监控和有效管理。     

Using Computer-Mediated Peer Review in an Engineering Design Course

Writing, especially when accompanied by feedback and revision, is a powerful enhancer for learning, as the writing-to-learn literature attests. Yet, writing as a vehicle for learning seldom appears in engineering content courses. We relate our experiences with a pilot program in engineering design funded through the National Science Foundation. Specifically, we focus on using Calibrated Peer Review as a platform for formative and summative assessment of integrated writing assignments in targeted courses. Our results show that students improved their skills in elements of engineering design and in writing. Additionally, assessment of the learning outcomes from the targeted courses were used successfully to document Accreditation Board for Engineering and Technology's criterion EC3 (g), “ability to communicate effectively,” in our latest accreditation cycle.      

移动P2P流媒体中基于有效容量的邻居节点选择机制

For Peer-to-Peer (P2P) streaming services in mobile networks, the selection of appropriate neighbour peers from candidate peers with demanding data is an important approach to improve Quality-of-Service (QoS). This paper proposes a novel Effective Capacity Peer Se-lection (ECPS) scheme based on effective capacity. In the ECPS scheme, the neighbour peer selection problem was modeled using the Multiple Attribute Decision Making (MADM) theory, which considered multiple factors of candidate peers, including Signal to Interference and Noise Ratio (SINR), residen-cy time, power level, security, moving speed, and effective capacity. This model could increase the suitability of ECPS for wireless mobile environments. Then, the Technique for Order Preference by Similarity to Ideal Solu-tion (TOPSIS) was used to solve the MADM problem and identify the preferred neighbour peers. Simulation results show that the ECPS scheme can improve the network throughput, reduce packet delay by about 82%, and al-most double the packet delivery ratio of the mobile P2P streaming service.     

4K超高清播出系统信息安全等级保护方案设计

为确保广东广播电视台4K超高清播出系统的安全性,按照国家广电总局信息系统安全等保的要求,需要设计一套完整的安全解决方案,防止外界非法操作对业务系统进行试探和攻击。广东广播电视台4K超高清电视安全以播出需求为基础,为适应全媒体时代下的电视节目的生产、播出,需要全面整合广东广播电视台的现有超高清、高清、标清系统资源,重构电视播出业务生产流程,对系统进行安全加固,满足当前电视播出信息系统安全等级保护的要求。