【作者】 黄国富；

【导师】 房胜；

【作者基本信息】 山东科技大学 ， 计算机系统结构， 2007， 硕士

【摘要】 日新月异的计算机科学和网络技术的迅速发展为未来多媒体应用技术的发展带来了无穷的活力。伴随着微电子技术、光电子技术以及无线网络技术的不断发展，计算机的发展已经进入了移动时代，以掌上电脑(PDA)、便携式电脑(Notebook PC)和穿戴设备(Wearable-Device)为代表的移动式计算系统日益普及，在移动中使用计算机、无线袖珍设备、将移动的主体通过网络与庞大的数字空间无缝地结合在一起，已经不再是梦想。本论文的研究目的是研究开发一套面向无线环境的交互式多媒体系统。本系统设计主要是通过802.11b无线网络环境来构建一个无线交互平台，使移动终端(如：PDA、Laptop)与数据服务中心，或者移动终端与移动终端之间通过上述平台来进行多媒体数据的传输以及信息的交互等。另外在系统设计和实现基础之上，对无线交互多媒体系统进行了测试，给出了系统运行的实验结果，并对系统性能加以分析。本系统主要有以下特色：第一、面向无线环境的无线交互式系统是一个移动的系统，它能够使得持有无线移动设备的用户可以在无线网络信号覆盖区域内享受移动式的服务MS(Mobile Services)，第二、持有移动终端的用户可以根据自身的需要向服务系统提出简单的交互请求(Simple Interactive Request)，从而满足用户的一些简单性的应用需求，实现简单的交互功能。论文首先分析了有线网络环境下进行多媒体音视频数据信息传输的研究现状、技术背景、流媒体数据信息的特点、在未来发展过程中用户对网络的需求，以及无线环境下交互式系统研究与设计的必要性、可行性和整个系统设计开发的技术基础。第二部分介绍了音视频编码的基本理论，对各种编码标准作了比较和分析，选择了适合无线环境下交互式多媒体系统的编码标准。第三部分在分析了无线网络传输特性之后，阐述了针对无线环境音视频数据编码及传输的设计方案。第四部分对无线环境的交互式系统进行了完整的逻辑设计，并详细阐述了各具体模块的功能。第五部分在交互式系统设计基础之上，对系统各个功能模块进行了实现，并给出了整个系统的实验结果和相关试验数据。文章末尾对无线交互多媒体设计进行了总结和展望。另外本文还对无线网络环境中，进行音视频数据传输时出现的声音延迟、动态带宽自适应以及音视频不同步等问题在相关章节中进行了一定的分析，并给出了可能的解决方案。更多还原

【Abstract】 With the rapid development of the network technologies multimedia applications based ontransmission have been motivated greatly. The fast developments of micro-electronic andphoto-electronic technologies, combining the network technology, gestate a new computing era.Mobile computing system based on personal digital assistant (PDA), laptop and wearabledevices has been used widely. It is not a dream for mobile users to operate computer whenmoving. They can connect to network to send and receive data anywhere at any time bydifferent ways. The cyberspace and physical space will be integrated into one whole space.In this context this paper intends to develop an interactive multimedia system based onwireless environment. The designed system mainly consists of a wireless interactive platformvia IEEE802.11b wireless network, which can allow the transmission of a large amount ofmultimedia data and interactive communication between mobile devices(PDA, Laptop), thecenter of data service, and mobile devices. In addition, we do some simulations to evaluate thedesigned system. According to the experiment results the system performances are analyzed.The designed system has the following characteristics. First, it is a mobile system supportinginteractive multimedia communication based on wireless environment, which can enable usersto enjoy mobile multimedia services anywhere at any time. Second, mobile users holdingwireless devices can send simple interactive requests to service system according to theirservice demands. This can gratify the interactive need of mobile users by providing thefunction of simple interactive commands.The first chapter analyses the status quo of multimedia transmission, its technologybackground, characteristics of streaming multimedia and the requirements of the possiblefuture development of the cable network. Furthermore, the feasibility and the technicalfoundation for the design of the interactive system based on wireless network are analyzed. Inthe second chapter the technological details of Audio and Video Codec are introduced.Comparing between several Audio and Video Coding Standards, we choose H.264 videocoding standard as a best choice for the interactive multimedia system working in wirelessenvironment. In the third chapter after analyzing the characteristics of wireless transmissionstandards, we present the transmission protocols RTP/RTCP and wireless standards 802.11b, which will be used in the proposed interactive multimedia system. Then we analyze thetransmission-related problems in wireless network, such as delay, self-adaptive bandwidth andsynchronization between audio and video. In the fourth chapter, we propose and design awireless interactive multimedia system, and its corresponding architecture, logical frame, andthe basic functions of each module are given in details. In the fifth chapter the functionmodules are implemented and some experiments are performed to test the efficiency of theproposed system. Finally the works are concluded and some future works are given.更多还原