To develop more sustainable transportation systems, societies worldwide are making efforts to increase the share of rail in transporting people and goods. Europe, for example, aims to reduce greenhouse gas emissions and become climate neutral by 2050. To this end, the European Green Deal, a set of policy initiatives by the European Commission, aims to cut emissions while improving people’s well-being [1]. Recognizing that the transport sector represents 25 percent of the world’s emissions, rolling out cleaner, cheaper, and healthier forms of private and public transportation is an important part of the European Green Deal. To mark the importance of increasing sustainability within the transport sector, 2021 was the European Year of Rail. The European Year of Rail highlighted that rail is one of the most sustainable, innovative, and safest transportation modes available today and will remain so in the foreseeable future [2]. With more than 200,000 kilometers of railway lines in the USA, 150,000 kilometers in Europe, and more than 100,000 kilometers in India, businesses and freight carriers can benefit from low-cost and increasingly competitive transportation solutions while reducing their carbon footprint [3]. For passenger traffic, traveling by rail is safe, as indicated by the extremely low fatalities per billion passengers/km, compared to those suffered by road users.
High-speed train travel is only possible using effective train control. A train driver without train control loses situational awareness and cannot react fast enough at speeds above 180 km/h. In Europe, the standard railway control-command and traffic management system is the European Train Control System (ETCS). This system is currently enabled by the Global System for Mobile Communications – Railway (GSM-R), the standardization of which has been driven mainly by the International Union of Railways (UIC). GSM-R, with its circuit- switched data communication, addresses the needs of critical voice communications and data transmissions for certain rail use cases defined in ETCS. Despite the success of GSM-R, it is becoming obsolete, due to the technological advancements of mobile communications systems, the widespread use of broadband services, and the increasing deployment of 5G cellular networks. 5G capabilities are also creating many new opportunities for railway systems, whether they concern use cases aboard a train, along railroads, or combining the operation of trains, signaling systems, operational centers, and workshops, which enable (semi-) autonomous train operations.
Recognizing the need to gradually replace GSM-R with the modern technology, the UIC has decided to lay the foundations of the Future Railway Mobile Communication System (FRMCS), of which the main goal is to fully digitalize railway operations, support an increasing level of automatic train operations (ATO), and embrace the possibilities offered by 5G without creating a railway specific cellular network technology. Besides these basic goals, FRMCS aims to be cost effective and future-proof, interoperable, and allow seamless migration of GSM-R to FRMCS. To meet these requirements, there are multiple challenges, which are being tackled with FRMCS standardization. This white paper discusses the challenges and opportunities of becoming successful in deploying 5G-enabled FRMCS for the digitalization of railway operations.