多路径并行传输方案研究

发布时间：2018-05-20 23:01

本文选题：多路径 + 并行传输　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：未来的通信网络将是一个包含多种不同接入技术的异构网络,能针对不同的用户需求提供不同的服务。同时随着多媒体业务量的爆炸式增长,特别是高清视频业务的广泛应用,单网络带宽已无法满足高清视频业务的传输需求,这些促使如何综合利用异构网络资源实现视频业务的高效传输成为了研究热点,而多路径并行传输技术为异构网络资源的合理利用提供了可能,在提高资源利用率和数据传输速率的同时,有效增强了数据传输的可靠性。本文首先简述了异构网络中多路径并行传输技术及其关键性问题。在多路视频传输过程中,若某条路径断开使得接收端无法收到所有分组而导致解码失败,影响视频正常播放;同时由于链路间差异性较大,各链路可承载带宽不同,传统视频传输不能动态适应不同链路的特征。而SVC编解码技术可根据链路状态自适应调整视频码率,为多路径并行传输方案提供了思路。其次,提出一种基于SVC编解码技术和EDCA机制的多路径并行传输方案。利用蜂窝网支持移动性的特点,将SVC视频业务的基本层数据分配到蜂窝网进行传输,保证基本层数据的可靠传输;利用无线局域网的高链路速率,将增强层数据分配到无线局域网进行传输,在保证视频流畅性的前提下,尽可能地提高视频质量。同时采用EDCA机制来保证无线局域网路径中重要性等级较高的数据分组优先接入信道,仿真结果表明EDCA机制可以有效地降低重要性数据分组的丢包率,并提升其吞吐量。最后,依托国家科技重大专项“泛在网络下多终端协同的网络控制平台及关键技术”,重点设计了基于SVC编解码技术的流媒体业务多路径协同传输方案,并在蜂窝网和无线局域网共存的环境下实现了视频业务的多路径协同传输,在用户离开无线局域网覆盖范围时通过蜂窝网传输基本层数据保证了较低分辨率视频的流畅播放;在用户重新关联无线局域网时恢复多路径并行传输,接收端重组基本层和增强层数据,从而提高了视频质量,即观看到高清视频,验证了SVC技术的弹性性能,项目验收顺利通过。
[Abstract]:The future communication network will be a heterogeneous network with many different access technologies, which can provide different services to different users. At the same time, with the explosive growth of multimedia traffic, especially the wide application of high-definition video services, the bandwidth of single network can no longer meet the transmission needs of high-definition video services. All these make it possible to utilize heterogeneous network resources to realize the efficient transmission of video services, and the multipath parallel transmission technology provides the possibility for the rational utilization of heterogeneous network resources. At the same time, the reliability of data transmission is enhanced effectively. In this paper, the multipath parallel transmission technology and its key problems in heterogeneous networks are introduced. In the process of multi-channel video transmission, if the disconnection of a certain path makes the receiver unable to receive all the packets, the decoding fails, which affects the normal play of the video. At the same time, because of the great differences between the links, the bandwidth of each link can be different. Traditional video transmission can not dynamically adapt to the characteristics of different links. The SVC coding and decoding technology can adaptively adjust the video rate according to the link state, which provides a train of thought for the multipath parallel transmission scheme. Secondly, a multipath parallel transmission scheme based on SVC coding and decoding technology and EDCA mechanism is proposed. The basic layer data of SVC video service is distributed to the cellular network to ensure the reliable transmission of the basic layer data, and the high link rate of the wireless local area network is used to make use of the characteristics of supporting mobility in the cellular network. The enhancement layer data is assigned to the WLAN for transmission, and the video quality is improved as much as possible under the premise of ensuring the video fluency. At the same time, the EDCA mechanism is used to ensure the data packet priority access channel with higher importance level in the path of WLAN. The simulation results show that the EDCA mechanism can effectively reduce the packet loss rate of the important data packet and improve its throughput. Finally, relying on the important national science and technology project "the network control platform and key technology of multi-terminal cooperation under the universal network", the multi-path cooperative transmission scheme of streaming media service based on SVC coding and decoding technology is designed. The multi-path cooperative transmission of video service is realized in the co-existing environment of cellular network and wireless local area network (WLAN). When the user leaves the WLAN coverage, the basic layer data is transmitted through the cellular network to ensure the smooth playback of low-resolution video. When the user reconnects with WLAN, the multipath parallel transmission is restored, and the data of basic layer and enhancement layer are reorganized at the receiving end, thus the video quality is improved, that is, the high definition video is viewed, and the flexibility of SVC technology is verified. The acceptance of the project passed smoothly.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.81

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