基于ASN.1的智能网编解码技术研究

【作者】 唐林；

【导师】 周亮； 王文胜；

【作者基本信息】 电子科技大学 ， 电子与通信工程， 2008， 硕士

【摘要】 本文的工作是研究基于ASN.1的智能网编解码技术的设计与实现。首先对ASN.1抽象语法记法和智能网的背景知识进行了概述性介绍,阐述了ASN.1抽象语法记法的定义、特点以及一般应用流程,并介绍了智能网的概念、体系结构、协议结构等课题背景知识。随后,研究了ASN.1抽象语法记法的规范和编码规则,描述了ASN.1定义的一些基本类型和它们对应的值,以及将它们组合成为更复杂类型和值的规则,并详细说明了可应用于对ASN.1记法定义的值编码的编码规则。接着,结合一般的编解码技术途径优缺点和课题自身的特点,提出了自己的ASN.1基本编码规则编解码设计方案。该方案中先根据ASN.1的记法规范和基本编码规则定义了一种格式串定义规则,具体应用协议的描述可以利用该规则编写为格式串。在格式串的基础上,利用二叉树数据结构,采用空值-插值-遍历编码的方法来完成基于ASN.1基本编码规则的编码功能;对于解码功能,采取的方法是解析-赋值-取值。然后,基于以上方案,使用标准C++语言实现了该ASN.1编解码模块。该模块包含编解码数据结构类、编码处理类和解码处理类三个大的组成部分,提供的外部接口简单,调用方便。最后,基于已实现的ASN.1编解码模块,编写了针对智能网INAP协议具体操作进行编解码的例程。在七号信令平台上,利用标准的INAP消息对编解码功能进行了对通实验。实验中,选取INAP的两个操作(启动DP、连接)进行了编码或解码测试。实验结果表明,所设计的编解码算法不仅能正确、快速、自动化地完成编解码功能,而且具有效率高、实现代码长度短的特点。更多还原

【Abstract】 This study presents the work of designing and implementing of the Intelligent Network(IN) encoding/decoding technology based on ASN.1.First,there are briefly guidelines for mainly background knowledges about ASN.1 and IN.We expatiate on the definition,feature and the application of ASN.1,and have guidelines for the conception,architecture and protocal of IN.Subsequently,we have studies about the standards of ASN.1 syntax and encoding rules.We describe the base data types in ASN.1 and the rules for combination these base data types to compound data types.There also is a deltailed description of encoding rules which can be used for values defined by ASN.1.Then,based on the analysis about general encoding/decoding technologies and requirements of this project,our algorithm about ASN.1 encoding/decoding is put forward.In this algorithm,based on ASN.1 syntax and base encoding rules,we define the rules of format-string.The descriptions of application protocal can be translated to format-string according to these rules.Based on format-strings and binary tree,the method of null-inserting-encoding has been used to finish INAP messages encoding. For decoding,the method to be used is parsing-assignment-getting.And then,we implement this algorithm module by using c++ language.There are three classes in the module which has been implemented,datahandle,datahandle_s and datahandle_r.The interface of this module is simple,so you can use it easily.Finally,based on the ASN.1 encoding/decoding module which has been implemented,we implement an INAP encoding/decoding example program.Depending on the INAP criterion messages,we have some experiments about functions of the encoding/decoding module.In these experiments,we choose two INAP operations, Initial DP and Connect,for decoding and encoding test.Test results show that,the designed module not only can correctly,rapidly and automatically finish its functions, but also has features of high effiency.更多还原