流媒体技术在综合网络中的应用

【作者】 高卓；

【导师】 桑楠；

【作者基本信息】 电子科技大学 ， 计算机应用技术， 2007， 硕士

【摘要】 随着网络技术、计算机技术、通信技术的发展,企业综合信息网络逐渐形成了三层结构:最底层的是以现场总线为基础的底层工业控制网络,位于第二层的是企业内部网,最上面的是Internet。由现场总线网络、Intranet、Internet三层网络构成的企业综合信息网络简称为综合网络。工业现场总线发展的一个趋势是在现场总线中实现多媒体信息的传输。工业网络中,多媒体的应用主要包括两个方面:视频监控和工业图像处理。然而,在现场总线上传输多媒体信息,必须要考虑两个方面:一是保证多媒体信息的传输不会影响到现场总线的正常功能,即需要保证控制信息传输的实时性和可靠性;二是由于现场总线带宽的限制,必须考虑到多媒体传输可以应用的领域,同时还要考虑选择合适的多媒体压缩标准。流媒体技术是近年来兴起的一种新的媒体信息传输技术,并以其众多的优点吸引了业界的目光。利用综合网络三层结构的特点,将流媒体技术应用于综合网络中,在不同的网络层次上实现流媒体系统的不同功能,最终实现综合网络中实时流媒体传输,将企业的工业控制网络和信息网络充分融合,是本课题研究的目标。论文研究的重点包括:第一,多媒体信息在低带宽环境下的压缩和传输问题;第二,在现场总线中,多媒体信息和控制信息混合传输环境下,现场总线正常功能的实时性和可靠性保障技术;第三,将流媒体系统应用于综合网络时,流媒体系统的QoS保证策略;第四,基于系统的理论研究,以视频监控在综合网中的应用为例,提出一个具体的系统实现方案,以及部分软硬件的设计实现。相对于已有的研究,本论文的特色在于:一方面针对综合网络三层结构的特点,将流媒体的概念引入到综合网络中,并采用在不同的网络层次实现不同功能的方法,实现了在综合网络中流媒体的实时传输;另一方面提出了将控制网络和多媒体网络相融合的QoS保障方法,设计了基于带宽预留策略的自适应传输算法,以保证现场总线控制信息的实时性和可靠性,并采用多缓冲存储策略为流媒体系统提供一定的QoS保证。更多还原

【Abstract】 With the development of computer technology, network technology and communication technology, the enterprise integrated information network has gradually built up a three-tier structure: the lowest layer is the basic industrial control network based on field buses, the second layer is the factory intranet, and the topmost layer is the Internet. The enterprise integrated information network composed of the field bus networks, Intranet, and Internet is called integrated network for shot.In industrial networks, multimedia systems are playing a more important role. In this area there are two main types of application, visual monitoring and image processing. Nevertheless, special care must be taken in order to assure that the introduction of multimedia traffic does not affect the normal functioning of the field bus network. Another aspect to be considered is the range of applications where the multimedia transmission system is possible, given the available bandwidth limitations, which will require a careful selection of the compression techniques to be used.Streaming media is a new raised media information technology in recent years. With a large number of advantages, it has attracted the industry’s attention. With the three-tier network feature of integrated network, the objectives of this research is to apply the streaming media technology to integrated network, realizing different functions at different network levels, creating the real-time streaming media transmission in integrated network, and achieving the fully integration of industrial control networks and information networks.The main points of this thesis are: First, the compression and transmission of multimedia data in low bandwidth environment; Secondly, the real-time control and reliability of control data in the mixed transmission of multimedia and control information; Thirdly, the QoS gurantee strategy when appling the real-time streaming media system in integrated networks; Forth, based on the theoretical study and used the video surveillance applied in integrated network as an example, proposed a specific solution, and partly given the hardware and software design and realization.Comparing with the existing research, there are two features in the thesis. In one aspect, the concept of steaming media is introduced to the three-tier structure of integrated networks, and the real-time transmission of streaming media is finally achieved through implementing different functions in different layer of the integrated networks. In the other aspect, the QoS guarantee method is given when achieved the full integration of the industrial control networks and the information networks. The bandwidth reserved algorithm is designed to guarantee the real-time transmission and reliability of control data. The multi-buffer storage strategy is used to provide some QoS for real-time streaming media.更多还原