【作者】 贾宏伟；

【导师】 刘杰；

【作者基本信息】 北京邮电大学 ， 通信与信息系统， 2008， 硕士

【摘要】 目前,随着科学技术的飞速发展,人类已经全面步入信息社会,作为首选通信方式的传统电话网所提供的单纯的语音信息服务已经越来越不能满足人们对信息多样化的需求。多媒体技术的出现为人们提供了更多的选择,也为多媒体通信奠定了基础。与此同时,IP网络的发展为多媒体通信提供了良好的载体,人们可以通过互联网获取文字、图像等信息,也可进行音频、视频、数据的实时交互,从而进一步拉近了人与人之间的距离,极大的丰富了人们信息共享的方式,也进一步促进了经济和社会的发展。尤其是近年来,随着IP网络的日渐普及和带宽的不断增加,基于IP网络的多媒体应用也日渐增多,像多媒体视频会议、远程教学、远程医疗、远程呼叫中心等远程多媒体服务的应用逐渐热门起来,成为新的经济增长点。在本文中,我们采用一种将传统的电话网与IP网络相结合的方式,为用户提供远程多媒体综合服务。用户可以使用电话、电脑等多种终端通过电话网或IP网络获取音、视频及数据等多媒体信息,从而实现信息获取方式的多样化。论文首先分析了多媒体信息的特征以及多媒体信息传输的特殊要求。在此基础上针对基于IP网络的多媒体信息远程传输的相关技术进行深入研究和比较,包括多媒体通信系统中通信协议的研究,多媒体通信系统中传输方式的研究,多媒体通信系统通信服务质量的研究,多媒体数据压缩及编码技术的研究以及多媒体数据库的相关研究等。基于对以上技术的研究,本文提出了一种依赖“IP+电话网”环境实现的远程多媒体综合信息服务系统,实现以电话网为基础的音频呼叫以及基于IP的文字实时交互和视频呼叫功能(包括白版、文字聊天等),从而为用户音频、视频以及数据等多媒体信息的综合服务。文中详细说明了系统的实现过程,包括借助呼叫中心的相关技术实现的基于电话网的音频呼叫功能和利用NetMeeting实现的基于IP网络的视频、数据交互功能等,并针对多媒体信息在数据库中的存储和提取进行了探讨。更多还原

【Abstract】 Now with the development of science and teconology, we have entered into the information society and the pure voice service offered by the traditional Public Switched Telephone Network (PSTN), which is used to be the first choice for communication, now can not meet the needs of people who long for multimedia informations. The multimedia teconology gives us more choices and it also lays the foundation of multimedia communication. In the meantime, the development of IP network offers a good support for the multimedia communication while people could get information of words and images and even interactive audio and video and data though the Internet which shortens the distance between people and advances the development of the economy and society. In recent years, with the popularity of IP network, the multimedia applications have became more and more popular like multimedia video conference, distance learning, distance medical treatment, distance call center and so on.In this thesis, a method of combining the traditional PSTN with IP network is adopted to offer distance multimedia combined services which allow people to get information of audio、video and data using telephone or computer.The features of the multimedia information and the special requirements of the multimedia communication are analyzed in the first part of the thesis and then the related technologies of the multimedia communication based on IP network are researched including the multimedia communication protocols, communication modes, the Quality of Service (Qos), the data compression and coding and the mulimedia database. Based on the researches above, a distance multimedia combined services system based on the combination of PSTN and IP network will be put forward which offers the service of audio communication though PSTN and video and data communication though IP network(including white board、text chat, etc). The realization process of the system is specified in the next part of the thesis including the audio communication functions based on PSTN achieved with the benefit of call center technology and the video and data communication functions based on IP network using NetMeeting. The question of storage and withdraws of the multimedia information from the database will be discussed at last.更多还原