【作者】 林潇；

【导师】 蔡坚勇；

【作者基本信息】 福建师范大学 ， 光学工程， 2007， 硕士

【摘要】 随着无线移动通信技术的迅猛发展，无线网络以其有别于有线网络的无线延伸和移动性好等优势逐渐被应用于诸多领域。目前，面向无线通信网络的视频传输技术已成为当今信息科学技术的前沿课题，主要应用于现场监控中的光学动态图像的远程采集传输。实时视频传输具有数据量庞大、延时敏感等特点。在有线网络上影响视频传输质量的主要有网络的拥塞状态，而无线移动信道存在着带宽有限、带宽波动和误码率高等特点，因此，在无线网络上进行视频传输的过程中，必须从网络拥塞和无线信道特性这两个方面来考虑信道的传输质量。本文提出了一种面向端对端的，基于无线信道传输质量的动态图像多信道选择传输策略。该策略分为3个部分：一是基于视频流编码特点的简单重传机制用于提高无线信道的可靠性；二是基于分组丢失率的流量控制，在提高无线信道带宽利用率的同时尽量避免网络拥塞，并通过视频质量调整来提高图像传输的实时性和连续性：三是该策略的核心部分是通过调度多个架构在网络层上的无线信道来提高传输．的质量与可靠性。模拟实验显示该策略用于双信道时，能够线性提高视频流的传输速率，并具有一定的稳定性。更多还原

【Abstract】 With the great development of the wireless mobile communication technology, there are more and more applications on wireless networks due to their predominant extensibility and mobility. Presently, video transmission technology over wireless network has been front edge of information science technology, and it’s mainly used in sampling and long distance transmission of optical motion picture in the area of local monitor. The characteristics of real-time video transmission are huge data quantity and sensitivity to the time delay. The main influence on the QoS of wired network is congestion, but on wireless network there are also other influences such as limited bandwidth, bandwidth variation and high error rate etc.This thesis mainly proposed an adaptive multi-channel selection mechanism for motion picture based on transmission quality of wireless channel. The mechanism included three parts: one was the simple resending algorithm depending on video stream encoding which can improve the reliability of wireless channel. The second was flow controlling mechanism based on packet loss rate so as to increase availability of wireless bandwidth during avoiding congestion, and make use of video quality self-adjustment in order to improve real-time ability and continuity of video stream. The last one was also the kernel. In this part mainly implemented a scheduling algorithm of wireless multi-channel on network layer which improved transmission quality and reliability.As the simulation experiments have shown, this mechanism applied to double-channel can increase linearly transmission rate of video stream, and enhances its stability.更多还原