【作者】 杜玮；

【导师】 阙大顺；

【作者基本信息】 武汉理工大学 ， 信号与信息处理， 2008， 硕士

【摘要】 随着计算机技术和网络技术的飞速发展,嵌入式技术和网络通信的结合越来越受到关注。VoIP是一种基于IP网络的数字化语音传输技术,嵌入式VoIP终端将是未来嵌入式系统的一个重要应用,具有广阔的发展前景。SIP协议是VoIP系统中运用最广泛的信令控制协议,SIP正在迅速被电信业采用以构建下一代应用程序。SIP作为一个应用层的控制协议,可以用来建立、修改、和终止多媒体会话或会议。以SIP协议为基础的VoIP技术正成为研究的热门领域。本文正是在分析研究SIP协议和嵌入式技术的基础上,研究了一种基于SIP协议嵌入式终端的实现方法。本论文的研究工作主要包括:1.归纳总结了嵌入式体系结构和嵌入式操作系统。确定了以Samsung公司的ARM芯片S3C2410作为核心控制器,以Linux操作系统为软件平台。2.探讨了VoIP关键技术,重点研究了SIP的功能结构、实现原理、消息机制和工作流程。3.在嵌入式系统理论的基础上,结合Linux自身特点,讨论了基于Linux进行嵌入式开发的方案,并搭建了嵌入式开发环境。本文使用安装有Redhat9的PC作为开发主机,并在其上安装交叉编译工具,构建交叉编译环境。分析了vivi的目录结构、启动流程以及其移植的难点问题,成功地将其移植到系统中。分析了嵌入式Linux的内核特点、目录结构,实现了嵌入式Linux系统的移植。最后根据系统需要,以busybox为基础进行文件系统的移植。4.研究分析了oSIP协议栈的结构,研究其解析器模块、有限状态机模块、工具模块以及使用方法。以oSIP协议栈为基础,讨论了嵌入式SIP终端的系统结构,并实现了一种嵌入式SIP终端。最后对系统进行了测试与分析,测试表明本论文实现的基于SIP的嵌入式终端原型具备VoIP终端的基本功能,完全遵循RFC3261标准,并且可以和其它支持SIP协议的产品互通,在局域网内达到较好的通话质量。更多还原

【Abstract】 With the rapid development of Computer and Internet technology,the combination of embedded and network communication has been attracted more and more attentions.VoIP is a digital voice transfers technology based on IP networks, which identified by voice packet-switch.Embedded VoIP terminal will be an important application of embedded system.SIP protocol is the most widely used signaling control protocol in VoIP system, which is rapidly adopted by the telecommunications industry to build the next generation of applications.SIP is an application-layer control protocol that can establish,modify,and terminate multimedia sessions or conferences.VoIP technology which is based on SIP is becoming a hot area of research.This thesis researches a method to implement a embedded terminal which is based on SIP.The main contributions in this thesis are as follows:1.The thesis studies on the architecture of hardware and software systems,that is, taking S3C2410 ARM chip as the core controller and Linux operating system as software platform.2.This part discusses VoIP key technologies and studies the architecture, realization,message mechanism and signaling flow of SIP.3.Based on the theory of embedded system and combined with characteristics of Linux,the scheme based on Linux is proposed and development environment based on the embedded system is formed.In this thesis take a PC with Redhat9 to be the host.Cross-compile toolchains are installed on the host to construct cross-compile environment.The content structure,booting sequence and the difficulty of vivi porting are analyzed and vivi is ported successfully to the embedded system.The characteristics of Embeded Linux kernel,content structure are analyzed,and the kernel is ported successfully.According to the system requirement,based on busybox file system is constructed.4.In the third parts,the thesis researches the structure of oSIP protocol stack and Parser module,Finite State Machine module,and Facilities module.Propose the system structure of embedded SIP terminal and implement embedded SIP terminal based on oSIP protocol stack.At last,The thesis tests and analyses for the system after design on the SIP telephone terminal.The result shows that VoIP terminal, which is based on sip,achieves the requirements for all functions in this design and compliances with RFC3261 standards.更多还原