In this paper , its critical techniques and development be chiefly introduced first . and then the emphases is laid on the techniques and the design related to the audio terminal 本文首先对关键技术和发展情况做简要的介绍，接着主要论述会议电视语音终端设备的有关技术及其实现。
The paper takes a groping research on the satellite videoconference network management system based on a new mechanism , and realizes its management on both service channel and terminal 本课题在业务信道和终端两个方面实现了对卫星会议电视系统的网络管理，对新体制卫星网上的会议电视网管系统进行了探索性的研究。
It features more than 1 , 000 deluxe guestrooms and 40 dinning and banquet halls in different styles , the hotel offer ample facilities for business , recreation . beauty salon , shopping and many other services 高科技的设备为您提供方便，客房接入国际互联网，商务楼层、会议厅及东方宴会厅提供远程会议电视和视像服务。
In order to realize a military videoconference network management system cnms , the paper researches into the network management of videoconference system on a satellite network based on mf - tdma 本文对mf - tdma ( timedivisionmultipleaccess )卫星网上会议电视网管系统技术进行了研究，旨在设计实现一个军用的会议电视网管系统cnms 。
In 1997 , the technical cosultation , the project design and system realization and running , which are related to optical fber meeting televiion system and product line monitoring system , had been completed in cangnan post and telecommunication of zhejiang province 1997年完成浙江苍南邮电系统光纤会议电视和生产运行监视系统的技术咨询、方案设计、工程的实施与开通。
At present , digital video compression technologies are widely used in the area of communication , digital tv broadcasting and so on , and advocated a series of applications such as video conference , media storage . people will come into the time of digital information 数字视频技术广泛应用于通信、计算机科学、广播电视等领域,带来了会议电视、可视电话及数字电视、媒体存储等一系列应用,将人们带入数字化信息时代。
The encrytion system makes full use of structure characteristic of mpeg - ii , combined with secure performance demanded in videoconference . a selective encryption scheme of video stream is proposed making compromise of computation quantity and encryption intensity , which makes main emphasis on the study of the key management and uses cipher mechanism mixed by 3des symmetrical algorithm and rsa unsymmetrical algorithm 本加密系统充分利用mpeg -视频流的结构特性，结合会议电视安全性能的要求，对运算量和加密强度这一矛盾进行合理的折衷，提出了mpeg -视频流的选择性加密方案。
In recent years , the research of image coding method has become one of the most active fields in information technology by way of the imp of communication , medium store , multimedia computer technology , etc . especially in 21st century , with the development of electronic and communicate technology , it is possible to realize the video telephone , meeting tv , signal tv , information high way and etc . on this occasion , it inevitably becomes one of the main tasks to seek after the effective image coding method 作为通信、介质存贮、数据发行、多媒体计算机等技术的关键环节，图像压缩编码算法的研究是信息技术中最活跃的研究领域之一，尤其是进入21世纪以后，电子技术和通信技术的发展使可视电话、会议电视、数字电视、高清晰度电视、多媒体计算机、信息高速公路等的生产和建立成为可能。在这一背景下，探索高效图像压缩编码算法无疑将成为主要任务之一，对其研究也将成为国际公认的热点之一。
Through researching of the pvc of fr channel connected with satellite network , the paper realizes the meeting switch function of videoconference system . by cnms communicating with the distant terminal management agent ( tma ) of videoconferencing system , the management and control of videoconference terminal dvc are realized 在对卫星网的帧中继接入信道的永久虚电路pvc的研究基础上，实现了会议电视系统的会场切换管理；通过cnms与远端会议电视终端代理tma的通信，实现了对各会场的会议电视终端dvc的控制和管理。
The result shows the stack in which this paper developes , has the merit of stability , dependability and maintainability ; has a characteristic of running on windows and unix platform , can communicated with the main h . 323 termainal products of some domestic and international videoconferencing producers , which proves that our h . 323 stack completely accords with itu - t ' s standard of h . 323 recommendation , and reaches our designing requirement 结果表明本文所开发的协议栈具有稳定性、可靠性以及可维护性的优点；具有跨平台的特性，能够实现和国内外主要会议电视厂家终端产品的互连互通；完全符合itu - th . 323建议的标准，达到了设计的要求。
