Service availability analysis in communication-based train control (CBTC) systems using WLANs
Data communication technology is one of the key subsystem in communication-based train control (CBTC), which is an automated train control system for railways that ensures safe operation of rail vehicles using data communications. In CBTC systems, less service availability could cause train derailment, collision or even catastrophic loss of lives or assets. Therefore, the availability of data communication should be carefully considered in designing CBTC systems. In this paper, we propose two WLAN-based data communication systems with redundancy in CBTC systems. The availability is analyzed using continuous time Markov chain (CTMC) model. We also model the WLAN-based data communication system behavior with Deterministic and Stochastic Petri Net (DSPN). The DSPN solution is used to show the soundness of our proposed CTMC model. Numerical examples illustrate that the proposed systems with redundancy can significantly improve the availability of communication availability in CBTC systems.