Reliability Analyses And Evaluation Of GSM-R In High-Speed Railway

As a platform for the information transmission in high-speed railways, GSM-R takes the role of media of voice and data services for CTCS-3. The high reliability of GSM-R for safe operation is required. However, the assessment criteria for the reliability of GSM-R network are not well-formed currently. To carry out the reliability analysis and evaluation of GSM-R is essential for guaranteeing the communication quality.The reliability evaluation of GSM-R includes the network coverage, the communication quality and the quality of service, which summed up mainly in the physical characteristics and service characteristics of the network, respectively. The GSM-R channel is highly time-varying due to the complex railway environment and high speed of railways, and thus the main features of channels are deep fading and serious interference. Therefore, the channel propagation characteristics in high-speed railways are first analyzed in the study of physical characteristics. Then the interferences caused by the public GSM network and the transient spark pulse are explored. As for the service characteristics, handover is considered to study the influence on service. After analyzing the GSM-R service handoff strategy, a handover priority scheme based on the service of Enhanced Multi-Level Precedence and Preemption(eMLPP) in GSM-R is modelled and simulated by using Coloured Petri Network (CPN). Then the GSM-R service performance is analyzed. At the end of this paper, we propose a two-layer reliability evaluation index system, i.e. synthesizing indexes of the physical layer and service layer, respectively. The evaluation criteria are also given. The proposed index system covers the main aspects of the reliability evaluation.Our work can provide effective guidance for the practical application and promote the development of railway communication technology.