Reliability Analysis of CTCS-3 Train-Ground Communication System Based on 5G-R

The reliability of Chinese Train Control System Level 3 (CTCS-3) train-ground communication system is of great importance to ensure the safe operation of trains. The fifth Generation Mobile Communication for Railway (5G-R) is prospective for train-ground communication in the future. In this paper, the train-ground communication procedure of 5G-R (e.g., connection reestablishment, handover and train-ground data transmission) is tested by a semi-physical simulation platform. The test results, including the delay of different procedures together with the handover success rate, all can satisfy the quality of service (QoS) requirements. According to the communication procedure, deterministic and stochastic Petri net (DSPN) models of communication links and train-ground communication scenarios are established. Furthermore, the parameters of models are calibrated with the test data and protocol standards. We utilize $\pi$ -tool to simulate and analyze the reliability of the train-ground communication system under the interaction of multiple fault factors. The results show that even in the worst handover scenario where the station distance is 1 km and the train speed is 400 km/h, the reliability of the train-ground communication system based on 5G-R can still reach 99.9963 $\%$ . It not only meets the requirements of the train control services for the train-ground communication system, but also is better than the reliability of the GSM-R based communication system.