【作者】 陈颖；

【导师】 蒋铃鸽； 陈西林；

【作者基本信息】 上海交通大学 ， 电子与通信工程， 2007， 硕士

【摘要】 随着通信新技术,新业务,新需求的飞速发展,时间成为判断通信消息是否可靠,可信的重要标志之一。精确的“时间”标志及其在现代交换网络中的作用变得越来越重要。本论文主要研究交换系统中时间同步方案软硬件设计与实现。本论文的课题直接来源于公司级研发项目。结合本人在项目研发过程中涉及到的硬件电路板IETOD的开发,软件时间同步子系统的研发工作和攻读学位期间收集的时间同步协议研究内容,设计规划适合我国交换系统使用的时间同步网实现方案,从而可以有效的解决电信运营商迫切需要解决的时间不同步造成的各种问题。本论文中所提供的硬件解决方案已经成功的应用于实际工程,为中国网通打造了国内首个时间同步网。本论文的主要研究内容为:1.时间同步网相关理论研究。研究重点集中在两个方面:通信系统对时间同步的需求及时间精度的要求和分析研究目前国际上比较通用的时间传送协议和同步协议的工作原理,协议框架。2.硬件系统设计与实现。基于本人参与设计的硬件电路IETOD及其在北京网通时间同步网建设案例,研究通过硬件系统实现时间同步的几个关键技术点。3.软件系统设计与实现。尽管硬件实现具有可靠性高,精度高等优点,但是由于硬件实现方案需要比较大的人力和物力投资用于硬件的改造,周期较长。在此基础上提出软件解决方案以弥补硬件方案在这些方面的不足。通过本文的七个章节逐步深入,理论联系实际地阐述了交换系统中时间同步网的相关内容。第一章首先引出了课题研究的背景,内容。第二章着重解释了时间同步和时间同步网的概念。同时根据现代通信系统中网络架构,业务应用的不同,业务特点阐明了建设时间同步网的必要性。具体研究不同业务对时间同步的精度要求,从而在选择实现方案时可以根据该精度要求选择合适的方式,以较小的投入实现时间同步。第三章和第四章则在理论上详细分析时间同步的原理和技术(主要包括时间同步和时间传送两部分技术),阐述了各个协议的使用场合,进行优缺点比较,为全文提供理论基础。第五章结合本人参与研发的目前交换网络中比较普遍使用的S1240交换机中最新研发成功并使用的时间服务模块(IETOD),详细介绍硬件系统设计与实现。最后通过介绍利用时间服务模块(IETOD)搭建的北京网通时间同步网案例来讨论时间同步网建设中所涉及到的其他设备如传输网,网管系统等的组网关键技术点,给出一个完整的时间同步网硬件实现方案。第六章介绍软件系统设计与实现。尽管硬件实现具有可靠性高,精度高等优点,但是由于硬件实现方案需要比较大的人力和物力投资用于硬件的改造,周期较长。在此情况下,我们提出了通过在网管统一平台上内嵌实现同步模块的软件系统方案以弥补硬件系统方案在这一方面的不足。本章将通过介绍本人主要研究的软件同步策略和交换机同步机制来介绍软件方式的系统架构和主要工作原理。第七章全文总结和技术展望。更多还原

【Abstract】 With the appearance of the new technology, new applications, new requirements, people want to have more saftive, reliable and truthly communication. Time information becomes one of identification to analyse the communication quality. So the applications of time synchronization in communication network become more and more important.“This dissertation focuses on the software and hardware implementation of the time synchronization system for the switching network.The object of this research is base on one of the company development project, which is applied on site running. Together with my hard work on the key hardware board IETOD during design project process and lots of reference documents and papers about timing protocols and formuls during this paper researching process. In this paper,the theory,character and application sample of different timing protocol was studied and discussed. Finally,time synchronization solution,which applied on the communication network,was given and key technology was analyzed. The given solution can deal with the problem,which caused by the unsynchronization time between the different telecom user or different exchange device. It also can improve the QoS and manage quality of the telecom user. Now the hardware solution is applied on the first time synchronization network in China.The object of this research is:1.Research the related theory of time synchronization. Laid a strong emphasis on the research of the communication network requirement to time synchronization; requirement of time precision; study of goble international protocols, including time transmision and time synchronization protocols. 2 . Design and implementation time synchronization by hardware application. Based on the hardware circuit IETOD and application sample on Beijing TELCOM, Research key issues in hardware application.3 . Design and implementation time synchronization by software application.There have sevens chapters of this paper.Chapter 1 gives the decription of this research background and the research object, content etc.Chapter 2 introduces the ideas of time synchronization and time synchronization network at first. And analyze the different types application,character of different telecom services to make clear the importance of building the time synchronization network.Chapter 3 and chapter 4 defines the theory and technology of time synchronization (time synchronization technology and time transmission technology),popular time synchronization international protocols. It gives us the theory base to us.Chapter 5,Using IETOD board,which is an External Time Of Day module used in S1240 exchange, to show a hardware solution. And gives a strong proof to build a time synchronization network,considering the on site running condition.Chapter 6 shows a softerware solution,which used network manger system.Chapter 7 gives a conclusion and prospect.更多还原