Railway Network Evolution Why it is urgent to wait for 5G?

The 3GPP 5G standard is almost ready. If its first phase, completed in 2018, allows this standard to claim its 5G status, it will become totally standardized after the second round of standardization completed at the end of 2019. The 5G standard is aimed at three service areas: communication between users using their smartphones (eMBB), communication between machines (mMTC) and also critical communication requiring simultaneously reliability and reduced latency (uRLLC). Of course, these three kind of communication can be managed independently from each other. But the vehicular domain (connected cars or railway scenarios) could be the place where these three forms of communication would be strongly coupled. This paper highlights which 5G features could be deployed in the railway domain and why this unified 5G would be a more judicious choice than a 4G or any other similar standard.