无线网络可靠组播的研究与应用

发布时间：2018-05-25 04:00

本文选题：组播 + 数据分发　；参考：《电子科技大学》2017年硕士论文

【摘要】：随着互联网技术的不断发展,网络传输速率和质量不断提高,高清视频、音频等多媒体文件的需求也变得越来越普遍。然而由于这些文件大多都比较大,在网络中进行传输时就会占用较多的带宽资源,因此如何能够更有效地利用网络带宽资源并实现高速可靠的数据分发,已经成为了一个重要的研究课题。本文为了实现无线网络数据分发系统的多媒体文件高速分发,针对该系统的实时性、传输的高效性和可靠性需求,首先对当前主要的数据分发方式进行了分析和研究,然后结合实际需求设计提出了一种组播数据分发系统方案。该方案从组播协议和应用层编码两个方面对提升分发系统性能进行优化。组播协议方面,在现有的ALC协议的基础上引入了数据包内容与传输文件关联的思想,使得终端在接收数据包时可以知道该数据包内的信息所代表的文件内容,并使用该协议实现对应的组播系统。应用层编码方面,在对多种喷泉码技术进行研究后,提出了一种将降维快速解码方式与优化高斯消元解码方式相结合的选择解码方式,该方式根据终端接收数据包的情况选择适当的解码方式从而提高解码效率,最后通过仿真实验验证了该解码方式的高效性。本文的主要研究内容如下:(1)在研究现有喷泉码技术的基础上,针对现有RaptorQ码在解码时存在的时延和解码失败的问题,提出了选择解码方案,使得解码过程可以根据接收端对传输数据块的实际接收情况选择适当的解码算法进行解码,从而提高解码效率。(2)在组播传输协议ALC协议的基础上,引入了File Delivery Table机制,并将其改良ALC协议实现。在数据文件进行传输时,文件的相关属性信息将存放在FDT中与数据文件一起进行传输。在本设计中,由于采用了RaptorQ码进行应用层编码,FDT可以更好的帮助接收端对收集的数据包进行归类,方便下一步的解码。(3)设计了使用RaptorQ码作为应用层编码的组播分发系统的原型模型,并对其各个构成模块进行了详细设计与实现。最后,对该系统中的RaptorQ码的解码性能进行了测试。
[Abstract]:With the continuous development of Internet technology, the transmission rate and quality of the network are improving, and the demand of high-definition video, audio and other multimedia files is becoming more and more common. However, because most of these files are relatively large, they will occupy more bandwidth resources when they are transmitted in the network. Therefore, how to make more effective use of network bandwidth resources and achieve high-speed and reliable data distribution, Has become an important research topic. In order to realize the high-speed distribution of multimedia files in wireless network data distribution system, aiming at the real-time, high efficiency and reliability requirements of the system, this paper first analyzes and studies the main data distribution methods. Then, a scheme of multicast data distribution system is proposed according to the actual requirements. The scheme optimizes the performance of the distribution system from two aspects: multicast protocol and application layer coding. In multicast protocol, the idea of associating packet content with transmission file is introduced based on the existing ALC protocol, so that the terminal can know the file content represented by the information in the packet when receiving the packet. This protocol is used to implement the corresponding multicast system. In the aspect of application layer coding, after studying various fountain codes, a selective decoding method is proposed, which combines dimension reduction fast decoding method with optimized Gao Si decode mode. In order to improve the decoding efficiency, the decoding efficiency is improved by choosing the appropriate decoding method according to the data packet received by the terminal. Finally, the high efficiency of the decoding method is verified by the simulation experiment. The main research contents of this paper are as follows: (1) based on the research of the existing fountain code technology, aiming at the problems of the delay and the decoding failure of the existing RaptorQ codes, a decoding scheme is proposed. The decoding process can select appropriate decoding algorithm according to the actual reception of the transmission data block at the receiving end, so as to improve the decoding efficiency. (2) on the basis of the multicast transmission protocol ALC protocol, the File Delivery Table mechanism is introduced. And the improved ALC protocol is implemented. When the data file is transferred, the relevant attribute information of the file is stored in FDT for transmission with the data file. In this design, because the RaptorQ code is used for the application layer coding, it can better help the receiver to classify the collected data packets. A prototype model of multicast distribution system using RaptorQ code as application layer coding is designed, and each component module is designed and implemented in detail. Finally, the decoding performance of RaptorQ codes in the system is tested.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN92

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