Impact of the Optimization the RAM of the Railway Optical Transmission Infrastructure on Reducing the Line Blockage

Document Type : Research Paper


1 consultant of railway company

2 Deen of Islamic Azad University- Yadegar-e-Imam Khomeini (RAH) Share Rey

3 Associate Professor, Department of Industrial Management, Central Tehran Branch, Islamic Azad University, Tehran, Iran


The safe movement of the rail rolling stock is not possible without train control systems. Train control systems ensure safety somehow and they play a vital role in increasing the speed and the capacity of the transport; So that, the failure of the whole or part of it can cause safety disruption, reduce productivity and increase line blockage. Due to the fact that all train control telecommunication services are based on optical transmission networks, the interruption of these networks will cause the interruption of all train control services and as a result, the line will be blocked. Therefore, evaluating and improving the sustainability of the optical transmission infrastructure is essential. In this research, in order to predict the number of the blockages due to the disruption of the transmission infrastructure, the rail transmission network is evaluated in two stages. In the first stage, the parameters of Availability, Reliability and Maintenance (RAM) of the railway transmission network are evaluated, and are simulated using the Monte Carlo method. In the second phase, the RAM mechanism is simulated again by implementing a network failure repair reduction model. In both stages, the probability of the shutdown of the railway telecommunication network, the numbers of blocked lines have been obtained. Predicting the number of network outages and rail line blockages due to the interruption of train control services has been conducted for the first time in research. The results of this study showed that a 10% reduction in network repair time led to a three-and-a-half-fold increase in RAM levels and a 70% reduction in line blockage. These results will be of great value in increasing system efficiency as well as the satisfaction of the users.


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