优化TLV编码规则  

TLV Coding Optimization Rule

作　　者：王沁[1] 许娜[1] 张燕[1] 张晓彤[1] 

机构地区：[1]北京科技大学计算机系,北京100083

出　　处：《计算机科学》2008年第11期104-106,261,共4页Computer Science

基　　金：北京市科技重大项目"交互式数字电视信道传输核心技术开发"京科技发[2002]188号

摘　　要：抽象语法标记ASN.1是一种ISO/ITU-T标准,描述了一种对数据进行表示、编码、传输和解码的数据格式。ISO协议体系中的应用层协议使用了ASN.1来描述它们所传输的协议数据单元。ASN.1取得成功的一个主要原因是它与几个标准化编码规则(如基本编码规则BER)相关。TLV编码是指先对Tag编码,再对Length编码,最后对Value编码。BER编码确定的编码方式就是这样的。在实际的通信中,通常特定类型编码中数据的长度是已知的,在数据字典中有明确的标识。提出了一种优化TLV编码的方法,使用一个比特的标志位,将长度字段作为编码中一个可选择的项目,而不是必须存在的项目,以此来缩短TLV编码的长度。在满足需求的前提下,优化后的TLV编码可以大幅度地提高数据传输效率。ASN. 1 is one of ISO/ITU-T standards, which describes a kind of data structure used in representation, encoding, translating and decoding. Application layer of the ISO protocol sockets use ASN. 1 to describe protocol data unit used in the translatioru The main reason of the success of ASN. 1 is that it is closely related with several standard coding rules, such as BER. TLV code is composed of tag, length and value. This is the coding rule confirmed by BER. In actual communication,generally,the length of special type field is specific and unchanged, which can be definitely found out in data dictionary. Presented a method of optimized TLV coding method. By adding one：bit symbol, the method makes the length field become optional to shorten the total length of the data packet. This optimized method not only can satisfy the requirement of a variety of protocols, but also can greatly improve the translation efficiency.

关 键 词：ASN.1 BER TLV 优化编码 

分 类 号：TP393.07[自动化与计算机技术—计算机应用技术] TP393[自动化与计算机技术—计算机科学与技术]