The railway sector is currently acting in a fragmented way and in silos, corresponding most often to physical or functional subsystems or use cases, and the different owners/managers of the overall infrastructure at regional/national level, without global extensive view or full control of the global system involved by rail operations. With the progress of digitization, analogue devices based on relays were progressively substituted by digital ones, and it is more and more evident that enabling the communication between already existing digital tools for various subsystems can be beneficial. What is missing is an efficient, automated and standardized way for these integrated and interplaying systems to act as one ecosystem: sharing, integrating, identifying, correlating and exploiting the right data at the right time. In order to meet these challenges, the objective of LinX4Rail is to develop and promote within Shift2Rail framework and beyond, a sectorial common Functional Railway System Architecture. It will be supported by a widely adopted Shift2Rail Conceptual Data Model (CDM) that will, with the commitment of the Shift2Rail members, through Shift2Rail Programme Board Change Management Process, establish the standard for interactions between legacy and new systems and thus ensure sustainable interoperability between systems. The ambition of LinX4Rail is to achieve a comprehensive approach for the CDM, global system modelling specification and a strategy for implementation of technological breakthroughs, including RCA, with the inputs from a communication system perspective and give a vision of future evolution of Functional Railway System Architecture.