【作者】 潘曦；

【导师】 刘云；

【作者基本信息】 北京交通大学 ， 通信与信息系统， 2007， 硕士

【摘要】 包括音频和视频的多媒体信息已经成为了网络上重要的传输内容，而流媒体技术凭借其自身的技术优势在网络上得到了广泛的使用。近几年，随着无线网络的飞速发展，带宽的迅速提高，为流媒体技术在无线网络中的应用提供了坚实的基础。当前，基于无线网络的流媒体是无线网络应用的一个研究热点，同时也是难点。无线流媒体是无线网络技术和流媒体技术的结合。在无线网络方面，即将要在我国商用的3G网络，根据ITU-T定义，将可以提供最高2Mkb／s的数据传输速率，而基于IEEE802.11系列的Wi-Fi网络已经能达到54Mb／s(802.11a)的速率。在流媒体技术方面，H.264已经成为新一代编码标准，在同等受限带宽的情况下，能提供比以往任何编码技术更好的质量，同时用于流媒体传输的RTP／RTCP、RTSP协议也已经成熟。在移动流媒体方面，3GPP和3GPP2已经分别提出了针对流媒体的PSS和MSS规范，为流媒体在3G网络中的应用做好了准备。本文就是在此基础上，分析研究了无线流媒体的各项关键技术，提出了一套基于无线网络的流媒体平台方案，并在Wi-Fi和Internet／Intranet的网络环境中实现和测试了这套系统。本文首先说明了研究背景和无线流媒体的现状与发展；随后详细研究了流媒体的各项关键技术，重点是流媒体传输协议和MPEG-4、H.264编码技术以及如何在本系统中应用这些技术；接着研究将流媒体技术应用于无线网络的设计方法和关键技术，主要包括了无线流媒体系统的QoS保证，3GPP规范中的流媒体服务，H.264在无线网络中的传输；最后介绍了系统的设计思路、总体框架以及具体实现，并给出了系统实际运行时的结果。更多还原

【Abstract】 Multimedia information including the audio and video has already become the most important transmission content in the network, so with unique technological advantages, streaming media is widely used. In recent years, the rapid development of wireless network and the increasing wireless bandwidth make it possible that streaming media technology is used in the wireless network. Currently, the streaming media based on wireless network is a research focus, and it is also a difficulty.Wireless Streaming Media combines the wireless network technology and streaming media technology. In wireless networks field, 3G networks soon will be launched, according to ITU-T definition, which will be available 2Mkbps maximum data transmission rate, and Wi-Fi networks can achieve maximum 54Mbps (802.11a) transmission rate now, according to the IEEE802.11 series. In the streaming media field, the new H.264 coding standard can provide better quality than any previous coding technology in the same limited bandwidth circumstances and streaming media transmission protocol, such as RTP/RTSP, are also mature. In mobile streaming media field, 3GPP and 3GPP2 have already separately proposed the PSS and the MSS standard for providing streaming media services in the 3G network.Based on the study of wireless streaming media key technologies, this paper proposes a solution for streaming media system based on wireless network. The system is implemented and tested in the Wi-Fi and Internet/Intranet environment.Firstly, this paper states the research background and the development of wireless streaming media. Secondly, the key technologies of streaming media, including transmission protocols and coding standards, are presented. This part of the paper focuses on how to implement these technologies in the system. Third, how to implement streaming media in the wireless network is detailedly studied, such as QoS of wireless streaming media, the streaming media services in the 3GPP standard and H.264 transmission in wireless network. Finally, the design, framework and implement of the streaming media system based on wireless network are introduced. The implement and the result are the emphasis.更多还原