Analyze And Research On Interface L Of GSM-R Interoperability Test

As a special railway communications technology, GSM-R is now increasingly widely used in the field of the world railway, and contributes to the development of railway industry. The development of GSM-R technology has become China railway's technical policies. Three GSM-R Railways—Qinghai-Tibet line, Datong-Qinghuangdao line and Qingdao-Jinan line which have been respectively built on the altiplano,heavy transport line and busy line prove that our country has yielded some results in GSM-R.Along with the fast construction of GSM-R network in modern railway, the network interworking problem has drawn the attention of people both domestic and overseas gradually. To solve the network interworking problem helps to promote the application of GSM-R technology in China. It is the first time that China GSM-R network introduced Intelligent Network to implement the particular services in railway transportation and it is also the first time to execute the interoperability test of L interface between SCP and SSP.This paper analyzes and summarizes the problems existing in IN of GSM-R based on the test results of GSM-R interoperability test, with emphasis on the research to call release reason and second trigger of IN. This paper presents the logical procedure in SCP which is specific to the various application on railway on the basis of GSM-R IN technical specification, analyzes the call release reasons. This paper researches the trigger methods of GSM-R IN deeply, presents a scheme that avoids the second trigger by changing the use condition of optional IE in MAP messages.