Nokia: Overcoming barriers to FRMCS adoption

A Nokia white paper, "Overcoming the barriers to FRMCS adoption," outlines the critical transition from 2G-based GSM-R to the new 5G-based Future Railway Mobile Communication System (FRMCS).

The report positions FRMCS as the key enabler for the rail sector's digitalisation. Advanced applications like automatic train operation (ATO) and real-time video monitoring depend on its high-capacity, low-latency capabilities. The paper explores the significant market opportunity, the 5G-based technology, and the primary barriers facing the industry.

The US$58bn opportunity and market drivers

The report identifies two fundamental drivers compelling the migration. First, the 2G technology supporting the current GSM-R standard faces obsolescence. Vendors no longer plan further investment in 2G platforms, forcing an upgrade. Second, rail's digitalisation agenda demands performance that 2G networks cannot deliver.

The International Union of Railways (UIC) estimates the global investment in FRMCS could reach US$58bn, signalling a major opportunity for telecom vendors, MNOs and infrastructure partners.

Spectrum, architecture, and 5G technology

For telecommunications providers, the 5G-based architecture is central to the opportunity. A significant European win was the allocation of dedicated frequencies in both the 900 MHz and 1900 MHz bands for railway use. The allocation provides an expansion from the previous 4 MHz in the 900 MHz band used for GSM-R.

However, the European rail supplier association UNIFE offers a caution. It warns the newly available spectrum "remains relatively small and may not be sufficient on its own for all the operational and business applications envisioned by railways".

The reference architecture detailed in the report follows a standard 5G model, managing traffic through an Edge DC, Regional DC, and a Core DC. A key research focus is the 'Telecoms Onboard Architecture' (TOBA), which aims to reduce costs by standardising interfaces and incorporating mainstream 5G components for all train-to-ground communications.

Key barriers and the MNO service model challenge

The white paper highlights several critical barriers to adoption. The US$58bn estimated cost is the primary hurdle, as FRMCS must compete with other urgent rail investments. A fundamental, unanswered question for the telecoms industry is who will build, fund and operate these 5G networks. The report identifies three potential models

Despite the opportunity, the report notes that the UIC remains cautious of MNOs. The union states that current mobile operator business models, which focus predominantly on consumer services, are "nowhere near being able to offer the quality of service needed for critical railway communications".

Competing technologies and market fragmentation

While 5G forms the backbone of FRMCS, it faces competition from other technologies. The report notes that satellite technology, in particular, is emerging as a strong candidate for train location and supporting ETCS communications, especially in rural areas. Trials using satellite networks are already active in Italy, Spain, and the UK.

Furthermore, the paper highlights a significant risk of market segmentation, which UNIFE describes as a "two-speed" migration. European markets must focus on harmonisation with legacy systems like ERTMS. In contrast, markets in Australia, India, and Korea have more flexibility and a more urgent need to upgrade from analogue systems. The risk is that these non-European markets may "go for 4G rather than 5G technology" rather than wait for Europe to finalise 5G standards.

Timelines and key validation trials

The report describes the full migration as a phased process taking 10 to 15 years. However, pressure from GSM-R obsolescence means the UIC is pushing for deployment to start around 2025-26.

To meet the deadline, several key trials are validating the technology. The 5G Rail partnership, a US$15.4m European research project, aims to validate FRMCS Version 1 specifications and enable a viable time-to-market for products by the end of 2025.

The most prominent test, however, is Germany's 'Digitale Schiene Deutschland' programme. In that project, Nokia and Kontron are building a standalone 5G test network. The partners achieved a significant milestone in February 2022, completing the first Mission-Critical Push-to-Talk (MCPTT) call over the network. The report concludes that the success of these German trials is essential to demonstrate a "commercially viable roadmap" and accelerate the industry's transition to FRMCS.