Digitisation of transport is a tool for achieving the European Union’s political goals included in the Digital Single Market Strategy for Europe. For rail transport, digital innovation is required to increase its competitiveness. One of the tools of the digital transformation of railways is 5G networks, the fifth generation of wireless communication systems. The purpose of this article is to present the benefits of implementing 5G network for railway operators. Focus was placed on its innovative features, such as ultra-fast access to Internet services, very high connection reliability, and extremely low data transmission delays. Examples of new services for railway operators based on the capabilities of 5G networks were presented. This article describes the unique functions of the 5G network in which resources can be flexibly allocated depending on current traffic needs thanks to the network slicing function, e.g., for services of key importance to rail traffic and commercial services for other market segments. Roadmap proposals for transforming the current rail communication network infrastructure towards the target FRMCS system are presented. The analysis was based on source materials from Nokia Corporation, available literature, EU documents and regulations, as well as institutional studies of the railway sector.