The Design And Implementation Of Decoder And Encoder Of TAP3 Roaming Data Based On ASN.1 Specification

Previously all the telecom companies (including Satelite Mobile Company) used to exchange the roaming data in text format, including TAP1 TAP2 and TAP2+ versions. Although text format has the strongpoints of simpleness and easy-maintenance,nowadays it cannot meet the new telecommunication requirements because of its fixed format fixed record length and the fixed position, such as roaming service WAP GPRS. Owing to its high flexibility and safety, TD.57 has been widely used in telecommunication roaming system.Whereas the above questions exist, this article will summarize GSM communication theory ASN.l agreement and encoder/decoder rules and give a brief introduction about roaming billing system in telecommunication. It not only studies and analyzes TD.57 criteria based on ASN.l, but gives out the detailded design and implementation of ASN.l encoder/decoder engines. Since ASN.1 data has nothing to do with platform, this can facilitate the data exchanger.In Telecommunications Business, PRD TD.57 Version 3 (TAP3) , an ASN.1 Based data exchange Standard, provides a flexible notation for describing the abstract classes and values, and it can be easily extended according to the new inquiry of services. In this article, an introduction for ASN.1 with its encoding rules is given first. The uniqueness of TAP3 is discussed later. A pragmatic method is developed for encoding and decoding, indicating the direction for TAP3 application development.