【作者】 黄博；

【导师】 张乃通；

【作者基本信息】 哈尔滨工业大学 ， 信息与通信工程， 2010， 硕士

【摘要】 近些年,我国航天和空间通信技术飞速发展,空间应用呈现出多样性、长期性和复杂性等特点。深空通信与传统地面通信有着巨大差别,它所特有的间歇可用链路、动态长延时、大误码率、不对称信道等特点使它无法直接采用现有的TCP/IP协议。空间数据如何在深空环境下进行可靠传输,直接影响着深空通信的发展。延迟容忍网络(Delay Tolerant Network, DTN)作为一种通用的、面向消息的、可靠的体系结构,能够集成深空环境异构网络技术,它的提出为解决深空通信面临的问题提供了有效解决途径。本文首先分析了深空通信所遇到的难题,阐述了深空通信的体系结构及其网络协议,并归纳了深空通信的体系结构特点和未来深空网络发展趋势,然后介绍了延迟容忍网络的发展状况以及深空通信DTN应用研究面临的困难,讨论了深空通信应用DTN所需要解决的关键技术问题。如何针对深空环境研究DTN应用,将是空间通信技术领域的重要研究课题。当处理具有长延迟和间歇中断连接的节点间网络时,数据传送到目的地会遇到很大困难。DTN通过使用了一种新的具有存储转发技术的包裹层协议,采用保管传递功能提供了可靠的数据传输。为了更深入地研究这个协议,有必要在不同的网络环境进行仿真。本文采用NS-2网络仿真器搭建仿真模型,描述了一个延迟容忍网络仿真模型的实现,对包裹层协议进行仿真研究。仿真模型使用DTN体系结构的各项功能及包裹层协议进行数据传输,显示了延迟容忍网络的特性和功能。本文给出了一种分析包裹层协议的方法,评估和分析了包裹层协议的信息传输特性,为进一步研究延迟容忍网络包裹层协议提供了参考,为未来深空通信DTN应用的研究提供了理论依据。更多还原

【Abstract】 In recent years, China aerospace and space communication technologies develop rapidly, the spatial application presents a series of characters: diversity, protracted and complexity etc. Deep space communication has a huge difference from traditional ground communication, the special features of which with intermittent available link, dynamic high delay, big error rate, asymmetric channel make it not applicable to current TCP/IP protocol. How the space data carry on the reliable delivery in such deep space communication environment directly influences the validity of space network information.Delay Tolerant Network is a generic, message-oriented and reliable architecture, which can assemble the various network techniques in heterogeneous deep space environment. To solve the problems that deep space communication confronts, the concept of DTN provides an effective solution. Firstly, this thesis analyzes the problems which deep space communication is facing. By studying the architecture of the deep space communication and its network protocols, this thesis summarizes the architecture features of deep space communication and the future trend in deep space network. Then, the thesis introduces the development of the DTN architecture and the problems which DTN for deep space communication is facing, and discusses the key technical issues that DTN for deep space communications needs to improve. How to study the application of DTN for deep space communication will be an important task of research in space communication field.When dealing with networks with long delay and intermittent connectivity between nodes, data can have trouble getting through to its destination. DTN provides reliable data transfer with custody transfer, using a new bundle protocol with a store-and-forward technique. For allowing in depth analysis of this protocol, there is a need to have means for running simulations in different network environments. This thesis describes the implementation of a simulation model for running simulations on bundle protocol in NS-2. The simulation model shows characteristics and functionality of DTN when using various features of the DTN architecture and the bundle protocol for transmission. This thesis presents a method of the analysis of the bundle protocol and provides a reference for a further research on the bundle protocol of DTN and theoretical support for the research of DTN applied in deep communication, with the evaluation and analysis of reliability and information delivery features on the bundle protocol.更多还原