2021/11/02

Digitale Schiene Deutschland and its partners are developing an FRMCS System Design for the Digital Railway System

Key aspects of the 5G based Future Railway Mobile Communication System (FRMCS) have been investigated within four research projects by Digitale Schiene Deutschland together with the major industry partners Ericsson, Kontron Transportation, Nokia and Vodafone. The insights are paying into an FRMCS design that efficiently serves the needs of the digital railway system. 

 

Digitalisation, automation and artificial intelligence are key to a higher capacity and optimal utilisation of the rail network. Within the sector initiative Digitale Schiene Deutschland (DSD), Deutsche Bahn AG targets to take rail operations to a new level by testing and introducing innovative digital technologies for improving railway performance. The increased grade of automation comes with new use cases and more demanding data communication needs. Data rates increase due to the transmission of video and sensor information, while incident prevention and management systems require low latency and high reliability communication. 

 

Modern 5G technology will be the basis for a powerful and flexible Future Railway Mobile Communication System (FRMCS) replacing the currently running 2G based GSM-R system, which is not suitable to handle the connectivity requirements of the digital rail system and will end its lifecycle in the mid 2030s. A key design paradigm is the maximal utilisation of mainstream commercial off the shelf components serving the railway needs, without being designed explicitly for railways. In addition to 5G technology, FRMCS will utilise Mission Critical Services (MCX), a framework for providing specific functionalities to railway applications, standardised by 3GPP (3rd Generation Partnership Program).  

 

Together with major industry partners, DSD investigated various design aspects of FRMCS in four research projects. 

 

Within a collaboration between Ericsson and DSD, the general 5G end-to-end design for FRMCS has been studied. The partners discussed relevant 5G features, configurations and deployment options that serve digital railway system requirements. Low latency communication with minimized interruptions for enabling service continuity has been studied in context of cell handovers, edge deployments and border-crossing. 5G based Quality of Service (QoS) mechanisms have been investigated, resulting in recommendations on suitable configurations that reflect the targeted connectivity demands. Furthermore, a preliminary 5G reference architecture with options on network function deployments has been presented. More details on the project and its results can be found here. 

 

The support of MCX technology in FRMCS has been investigated in a collaboration between Kontron Transportation, a leading global supplier of end-to-end communications solutions for mission-critical and carrier networks. In support of the still ongoing FRMCS standardisation activities, the project focused on investigating how MCX can be maximally leveraged for FRMCS in order to serve the needs of future digital rail operations. Moreover, potential technical realizations, including MCX services, 3GPP building blocks and reference points in the FRMCS system were further elaborated. Finally, the integration of 5G and MCX in the FRMCS system has been investigated, resulting in technical recommendations for future FRMCS standardisation work. More details can be found here.

 

Railway operations are mission-critical in nature. Resiliency, therefore, plays a key role in enhancing the performance by minimizing service interruptions and ensuring safety. Within a collaborative project between Nokia and DSD, various architectural options and features available in 5G have been analysed towards their suitability for the resilience needs of future rail operation use cases. Redundancy concepts for the fiber optical trackside transport network, as well as active 5G components and the compute platform have been analysed. The applicability of various split options of the railway radio access network has been explored together with their impact on costs. Additionally, orchestration and security have been considered to achieve a resilient FRMCS network design. Further details of the collaboration and its results can be found here. 

 

Flexible and reliable data communication is key for railway digitalisation. For various regulatory and legal reasons, DB envisions to mainly rely on a DB-owned FRMCS infrastructure. However, this may have to be complemented with the usage of public networks, for instance as a fall back or capacity complement. In a joint project, Vodafone and DSD cooperatively developed and analysed benefits of hybrid FRMCS network architectures, offering redundancy in case the DB 5G network is not available. In addition, the hybrid approach offers possibilities for utilising both 5G networks in parallel to increase network capacity for non-critical rail operation applications. As a result, different feasible network architectures were concluded, for which recently specified interfaces in the 3GPP standardisation are employed. More details on the project can be found here. 

 

The four collaborative projects have been fruitful for the involved partners to align on architecture principles, to assess potential implementation options and to identify standardisation gaps, relevant for the ongoing standardisation process in the various bodies. The outcomes of the cooperations pave the way towards a future mobile communication system that not only fulfills the needs of digital railway system, but also allows to do so in a cost-efficient and future-proof way.  

 

 

In the download area you will find all four research reports as well as other publications of Digitale Schiene Deutschland.