The Analysis Of Communication Reliability Of Chinese Train Control System Of Level 3

At present, China Train Control System of level 3(CTCS-3)has been determined to work as a unified technology platform for the whole railway system in the high speed railways with speed of 300km/h or above in our country. Compatible with China Train Control System-level 2(CTCS-2), it can implement the bidirectional operation for the train in the use of CTCS-3 system. In CTCS-3 system, the Radio Block Center(RBC) generates Movement Authority(MA)based on the occupation of rail circuit, interblock system and other information. Then through GSM-R network it transmits the movement authority, rail parameters and temporary speed restriction to On Board Unit (OBU)and receives the location and train data send by OBU. Therefore, the communication reliability of CTCS-3 is very important, and it can affect the safety, reliability and stability of CTCS-3.Based on the engineering experience in Wuhan-Guangzhou and Zhengzhou-Xian high speed railway, this paper proposes a method which can locate the communication failure in CTCS-3, analyzes the reasons for the communication failure, and summarizes the factors influencing communication reliability. Then it analyzes the factors with the method of Analytic Hierarchy Process(AHP), obtains the influence weigh of these factors and then elicits the aspects which need to be considerated mainly in enhancing the communication reliability of CTCS-3. Given by the hardware failure, by the system reliability block diagram method, it analyzes the communication reliability in different network coverage mode and communication node redundancy mode. Finally, this paper introduces Markov model to analyze the communication reliability of CTCS-3, and then proposes and analyzes a new method which can enhance the reliability.