LTE协议栈中ASN.1模块的设计与实现

开发长期演进(LTE)协议必须实现针对无线资源控制(RRC)消息的ASN.1编解码模块,但传统的ASN.1编解码方案函数调用频繁,编码效率较低。为此,分析LTE协议栈的软件需求,提出一种ASN.1编解码模块设计与实现方案。该方案采用模块化设计,从而简化函数调用、提高编码效率。在TD-LTE无线综合测试仪的协议栈软件中实现并进行测试,结果表明,该方案可实现对RRC消息的编解码。     

H.323协议栈中ASN.1模块的设计与实现

对ASN．1及PER编码规则作了简要介绍，接着提出了一种ASN．1编解码模块在H．323协议栈中的设计与实现的方案。     

嵌入式VOIP系统中ASN.1编解码器的实现

抽象语法描述ASN.1已经被广泛地运用于协议通信。在VOIP应用中,同样也要用到ASN.1编解码。但是由于H.323协议栈本身的asn描述文件较大,使得传统的ASN.1编解码方案在资源有限的嵌入式系统中并不适用。文章在实际开发项目的基础上,提出了一个适用于嵌入式系统的解决方案。     

DSRC协议ASN.1模块的设计与实现

通过研究专用短程通信（DSRC）协议栈中的应用层部分,针对其中的ASN.1 PER编解码模块,设计并实现了一种编解码框架,框架包括ASN.1映射规则、通用编解码流程以及符合小设备应用的内存管理机制。良好的模块划分使得此框架具有较好的通用性。测试结果表明,此实现框架具有良好的性能,满足协议的实时性要求。     

网络电话中ASN.1编解码器的实现研究

简要介绍了抽象语法标记语言ASN.1,以及BER和PER编码规则,阐述了网络电话中H.323协议栈的ASN.1编解码器的设计与实现。     

基于BER的ASN．1编解码原理与设计实现

本文介绍了ASN．1和BER基本编码规则，分析了7号信令协议栈的TCAP层消息结构和ASN．1之间的关系，详细介绍了应用于信令中继系统中的ASN．1编解码模块的设计和实现。     

嵌入式SIP语音网关实时传真模块的设计和实现①

传真通信作为有一种传统的传输静态图像的手段,是现代通信技术的重要组成部分。分析了IP传真（FoIP）的现状,比较了存储转发和实时传真两种实现标准,然后在基于SIP的嵌入式语音网关基础上,给出了T.38实时传真模块的纯软件方案的设计和实现。该模块主要由T．30 Soft Modem和T.38协议栈两部分组成,分别处理PCM数据和IFP包,二者之间的数据交互通过数据泵完成,具有低耦合度和高可移植性,已投入实际应用并取得较好效果。     

IP电话中ASN.1 PER编解码模块实现机制的研究

IP电话对ASN.1编解码模块的要求,提出一种优良的ASN.1PER编解码模块的实现机制,并分析其性能。     

基于面向对象方法的ASN.1编解码的设计与实现

随着计算机和通信技术的发展，ASN．1作为多种协议在表示层的抽象语法记法，它的作用在多媒体通信，协议测试等领域都非常重要。该文采用面向对象的设计方法实现了ASN．1标准X690，同时，通过比较各种编码规则的特点，在BER编解码实现的基础上，给出CER、DER及PER编码的实现方案，据此实现的ASN．1编解码对外提供了一致的接口，具有很好的通用性。     

LwIP协议栈在SoPC系统中的实现

提出了基于μC/OS-Ⅱ的LwIP协议栈在SoPC系统中实现的方案.介绍了嵌入式TCP/IP协议栈LwIP,阐述了其移植原理;在SoPC系统上实现了LwIP协议栈的移植,并给出了在具体软、硬件平台上的移植实例.实验结果表明:移植后的协议栈实现了网络的基本功能,且运行稳定,为SoPC类型的Internet嵌入式系统应用提供了一个基于μC/OS-Ⅱ的小型网络模块.该方案可应用于信息电器和网络化的仪器、仪表方面.     

ASN.1及其PER编码在视频会议系统中的应用研究

抽象语法表符号1（ASN.1）在多媒体网络通信中起着非常重要的作用.ASN.1被用于描述基于H.323协议的视频会议系统的信令消息.介绍了ASN.1的基本概念、数据类型和数据表示方法,详细分析了ASN.1在网络传输编码中使用的分组编码规则（PER）,并结合H.323协议中所常用的数据类型举例说明了其信令消息的PER编码过程.     

Integrated Estelle and ASN.1 specification approach to automatic implementation of application protocol

Estelle currently does not support ASN.1 and encoding and decoding rules. Tools developed for Estelle and ASN.1 have been developed independently of each other. As such, ASN.1 tools do not support Estelle and vice versa. At present, due to these two separate specifications, implementation is time consuming. It is imperative to find a way for ASN.1 and Estelle specifications to be efficiently integrated to facilitate fully automatic implementation. This paper describes how Estelle and ASN.1 can be integrated to give a unified specification which can then be fed into a software environment to produce a truly automatic implementation of an application protocol, including encoding and decoding of protocol data units, when application layer protocols are specified in Estelle and in ASN.1. The integration approach is based on the powerful programming concept, Data Abstraction. The software that implements this integrated specification approach to automatic implementation of application protocol is called EASE (Estelle and ASN.1 Software Environment). To demonstrate the viability of the approach, the unified specification of the ISO ACSE and Presentation protocols are also presented.     

The design and implementation of an ASN.1-C compiler

Abstract syntax notation one (ASN.1) has been widely used in international standard specification: its transfer-syntax, the basic encoding rules (BER), is used as the external data representation. A BER implementation called the ED library is presented. The ED library includes a number of encoding and decoding routines that may be used as primitive functions to compose encoders and decoders for arbitrarily complicated ASN.1 data types. Based on the ED library an ASN.1-C compiler, called CASN1, is designed and implemented to free the protocol implementers from the arduous work of translating protocol-defined data-types and constructing their encoders and decoders. Given an ASN.1 protocol specification, CASN1 automatically translates the input ASN.1 modules into C and generates the BER encoders and decoders for the protocol defined data-types. The CASN1 design principles, user interface, and some example applications are discussed. The performance of the ED library and generated CASN1 code is also measured and discussed