Availability analysis of next generation CBTC data communication systems

Communication-based train control (CBTC) systems are automated train control systems using wireless communications. Data communication is extremely important in CBTC systems. Train ground communication system which includes too many interfaces between various subsystems and excessive ground equipment is used as traditional CBTC data communication system. In next generation CBTC systems, train-to-train communication is adopted with the advantages of higher-speed, larger-capacity per unit time and the briefer structure in comparison with traditional CBTC system. Although train-to-train communication based CBTC systems has been implemented in urban rail systems. The system availability has not been studied before. In this paper, deterministic and stochastic Petri nets(DSPN) is used for the CBTC system to characterize its normal operation probability. Several typical data communication scenarios are depicted and simulated with DSPN. The impact of different scenario parameters on CBTC system operation is discussed. The availability of the next generation CBTC system is compared with the traditional CBTC system as well.