The Digital Railway supported by FRMCS

As discussed in our earlier post, the long-standing 2G cellular standard for rail communication, known as the Global System for Mobile Communications–Railway (GSM–R), remains in use across Europe, China, India, Africa, and Australia. However, software and hardware vendors predict that this early digital cellular technology will start to be phased out in 2025, as a new 5G-based system specifically for railway applications is expected to be introduced.

According to the European Union Agency for Railways (ERA), GSM–R supports communication between train drivers and traffic control centres with features such as group communication, location-dependent addressing, priority levels, railway emergency calls, and shunting communication. This system enables data transmission between trains and control centres at speeds exceeding 300 mph.

Yet, GSM–R is beginning to show its age. While it is adequate for basic voice communication, its 4 MHz bandwidth, which supports multiple 200 KHz channels, limits its functionality. Downlink communications use the 876–880 MHz range, while the uplink operates at 921–925 MHz.

The maximum data transmission rate for GSM–R is just 9.6 kbit/s, making it unsuitable for real-time data communication. Its capabilities are essentially limited to sending SMS text messages, with little capacity for anything more advanced.

The Future Railway Mobile Communication System (FRMCS), a 5G-based successor to GSM–R, will provide both voice and data services for railway communications. The FRMCS project is being led by the International Union of Railways (UIC) in collaboration with major rail infrastructure companies and telecom solution providers. It is set to be based on the 5G 3GPP standard, meaning it will not require a railway-specific cellular network technology.

FRMCS, which will use the standalone 5G NR specification, is expected to be finalised by the end of 2022. This new standard will operate on harmonised frequencies at 900 MHz and 1900 MHz to ensure interoperability for rail command and control systems as they transition from GSM–R to FRMCS.

This seems questionable from @SNCFVoyageurs

Asserts that train operational comms is mostly uplink & user connectivity downlink, so OK to share FDD public networks

Hmm. Growing use of uplink data from public usage, often with low latency needs pic.twitter.com/JNxHVJvaNL

— Dean Bubley (@disruptivedean) November 14, 2023

Mobile network operators will also be able to offer 5G connectivity for train passengers, collaborating with railway companies to provide the high-bandwidth digital services needed to streamline modern train operations.

Currently, many rail operators offer Wi-Fi onboard or install repeaters to enhance mobile network coverage within carriages. However, these solutions can be costly to maintain and upgrade, and repeated signals can cause interference when train doors open. An alternative solution is for public mobile operators to provide passenger connectivity through their existing 5G networks, with additional 5G towers placed along major rail lines.

To improve 5G signal penetration, train windows can be fitted with special “5G-friendly” glass, which allows signals to pass through more easily (standard window glass is often coated to reduce solar radiation inside the carriage). This approach reduces the need for expensive Wi-Fi and repeater systems, enabling mobile operators to deliver high-speed broadband services to passengers more efficiently.

In their webinar last year, Wray Castle stated that FRMCS is not simply a replacement for GSM-R nor is it a single specific technology. In fact, UIC have stated that FRMCS is technology agnostic. The webinar discussed:

• What is FRMCS and how does it differ from GSM-R?
• How soon will railways be replacing GSM-R?
• Is there a migration strategy?
• Do we have sufficient radio spectrum?
• What is the most probable technology that will be used?

The video of that is embedded below:

Wray Castle also conducts regular courses on this topic. Details here.

Related Posts:

• The 3G4G Blog: Future Railway Mobile Communication System (FRMCS)
• Connectivity Technology Blog: Future Spectrum Demand for Rail Communications
• Connectivity Technology Blog: 'Gigabit Innovation Track' (GINT) Gets Green Light in Germany 

Future Railway Mobile Communication System (FRMCS)

I have been meaning to write on this topic for a very long time. The discussion started back in 2016 when the limitations of GSM-R were obvious and it was recognised that a successor will be needed sooner or later. The International Railway Union (UIC) published a user requirement specification in their paper “Future Railway Mobile Communication System - FRMCS”. This is available on 3GPP server as liaison statement S1-161250.

As 3GPP notes in their article, this was the trigger for them to go ahead and start the studies. Then in Release 16, 3GPP TS 22.289 "Mobile communication system for railways" outlined the requirements for railway communication, beyond the 3GPP Future Railway Mobile Communication System (FRMCS) Phase 1 specs. Details are available on this post here.

Source Tweet

The latest version of 3GPP TR 22.889, Study on Future Railway Mobile Communication System; Stage 1 is from Release 17. The introduction to the document clarifies:

The railway community is considering a successor communication system to GSM-R, as the forecasted obsolescence of the 2G-based GSM-R technology is envisaged around 2030, with first FRMCS trial implementations expected to start around 2020. 

The Future Railway Mobile Communication System (FRMCS) Functional Working Group (FWG) of the International Union of Railways (UIC) have investigated and summarised their requirements for the next generation railway communication system in the Future Railway Mobile Communication User Requirements Specification (FRMCS URS). The present document is based on this input given by the UIC/ETSI TC-RT 

Study on FRMCS Evolution (FS_eFRMCS), available as SP-201038 clarifies:

The UIC FRMCS programme was recently releasing stable version 5.0.0 of the User Requirement Specification, version 2.0.0 of the Functional Use Cases and a new specification item, version 1.0.0 of the Telecom On-Board System - Functional Requirements Specification, as a further step in the evolution of the FRMCS specifications. The UIC FRMCS Programme is developing all the technical conditions for the 5G FRMCS, with the main objective to make available a “FRMCS First Edition” ecosystem available for procurement by Q1 2025.

The UIC FRMCS 3GPP Task Force has been identifying and analyzing impact of this newly released set of FRMCS specifications on existing use cases and requirements collected in TR 22.889. The UIC FRMCS 3GPP Task Force analysis has concluded that refining existing use cases, defining new use cases such as merging railway emergency communications and real-time translation of conversation, and deriving potential new requirements, will be necessary to align FRMCS and 3GPP specifications. The potential impact on normative work is estimated to be limited and much less compared to the study work.

As approved in SA1#90-e (S1-202245), TR 22.889 has now been re-named to TR 22.989 from Rel-18 onwards (latest version is TR 22.989 v18.0.0) to make it visible to the Rail community to be able to follow the 3GPP normative work in line with their needs. It is of most importance for the Rail community that specifications from different organisations (i.e. UIC, 3GPP and ETSI) are all aligned.

Due to the expected 3GPP work overload in Release 18 (SA1 and downstream groups), it is proposed to reduce the scope of the present Rel-18 study to evolution of critical applications related use cases only already identified by UIC – what is really essential for the railways as part of the “FRMCS First Edition” and the migration phase from GSM-R to FRMCS. 

Study of non-essential use cases (e.g. evolution of performance and business use cases) shall be postponed to Rel-19.

This plan is from 2019 so quite likely that it is already outdated. It does provide an idea on different steps and trial plans. Some of this was also covered in the 5G RAN Release 18 for Industry Verticals Webinar detailed here.

Finally, as this image from Arthur D. Little highlights, there is a lot of other interest in addition to FRMCS for 5G in railway. Report here.

Related Posts:

• The 3G4G Blog: '5G RAN Release 18 for Industry Verticals' Webinar Highlights
• The 3G4G Blog: Three New Standards to Accelerate 5G Wireless Wireline Convergence (WWC)
• The 3G4G Blog: 3GPP's 5G-Advanced Workshop Summary
• The 3G4G Blog: 3GPP's 5G-Advanced Technology Evolution from a Network Perspective Whitepaper
• Telecoms Infrastructure Blog: Bringing Connectivity to Underground Rail Network
• Connectivity Technology Blog: Deutsche Bahn to get Seamless Mobile Network Along all Tracks
• Connectivity Technology Blog: China Unicom Brings 5G Connectivity to Nanjing Metro 

'5G RAN Release 18 for Industry Verticals' Webinar Highlights

5G PPP held a virtual workshop on RAN Release 18 for Industry Verticals on June 23rd, 2021. The workshop was organised by 3GPP Market Representation Partners (MRPs): 5G-IA, 5GAA, 5G-ACIA and PSCE.

It features a fireside chat with new 3GPP RAN TSG Chair, Wanshi Chen. In addition to this, the workshop then provides a deep dive on new requirements from verticals, spanning automotive (5GAA), manufacturing (5G-ACIA), critical communications and public safety (TCCA with PSCE), broadcasting and media (5G-MAG), satellite (ESOA), rail (UIC), maritime (IALA) and energy (EUTC).

5G-SOLUTIONS came on board as a 5G PPP project supporting verticals with the 5G-EVE and 5G-VINNI 5G network infrastructures alongside RAN specialists doing standardisation work applicable to multiple verticals.

The video of the webinar is embedded below. In addition, you will find timings of when a particular talk starts and a link to the slides (if shared/available)

Timings:

• 0:04:21 Fireside chat with Wanshi Chen, Qualcomm and 3GPP RAN TSG Chairman
• 0:21:00 NTN Requirements in Rel-18 by Nicolas Chuberre, Thales Alenia Space (slides)
• 0:31:40 Multiple verticals: Andrea Di Giglio, 5G SOLUTIONS (slides)
• 0:36:35 Media and Broadcasting: David Vargas, BBC and 5G-MAG Chair of CD-T WG, Proposals for 3GPP RAN Rel-18 (slides)
• 0:43:19 Maritime: Hyounhee Koo, Synctechno and IALA, Maritime Requirements on 3GPP Rel 18 RAN Studies/Works Priorities (slides)
• 0:46:12 Rail: Ingo Wendler, UIC, NR Narrowband Channel Bandwidth - Railway Use Case (slides)
• 0:50:02 Utilities: Julian Stafford, EUTC 3GPP RAN Rel-18 Requirements (slides)
• 0:58:35 Utilities: Erik Guttman, Samsung 5G Smart Energy Infrastructure (slides)
• 1:05:45 Multiple verticals: Mathew Webb, Huawei and 3GPP RAN 3GPP Release 17 and Release 18 support for industry verticals (slides)
• 1:15:19 Public Safety/Critical Communications: Tero Pesonen, TCCA Chair, joint presentation with PSCE, 3GPP MRP Mini Workshop: 3GPP Rel 18. Requirements from industry verticals (slides)
• 1:20:15 Multiple verticals: Thierry Berisot, Novamint and 3GPP RAN, Industry Verticals and Rel-18 RAN (slides)
• 1:32:56 Manufacturing/IIoT: Michael Bahr, Siemens and 5G-ACIA WG 1Chair and An Xueli, Huawei and 5G-ACIA WG1 Vice Chair 3GPP RAN Rel-18 for Industry Verticals (slides)
• 1:42:20 Automotive: 5GAA Maxime Flament, CTO Input to RAN 18 Rel-18 Workshop (slides)
• 1:53:35 Interactive Session 2
• 2:04:36 Passive IoT for 5G-Advanced, Mathew Webb, Huawei and 3GPP RAN (slides)
• 2:14:59 Template A for Interactive Session 2
• 2:20:40 Critical Communications / Public Safety requirements for Release 18 
• 2:26:00 Closing Remarks

Official page here.

The slide above nicely summarizes 3GPP RAN Verticals up to Release 17.

Related Posts: 

• The 3G4G Blog: 3GPP's 5G-Advanced Workshop Summary
• The 3G4G Blog: 3GPP's 5G-Advanced Technology Evolution from a Network Perspective Whitepaper
• Connectivity Technology Blog: Ericsson Explains Internet of Drones and 3GPP UAV Roadmap
• The 3G4G Blog: 3GPP RAN Plenary Update and Evolution towards 5G-Advanced
• The 3G4G Blog: Introduction to 5G Reduced Capability (RedCap) Devices
• The 3G4G Blog: 3GPP Standards on Edge Computing
• Connectivity Technology Blog: 5G Drone Cell Towers 

Changes in LTE pricing strategies

Its been a while since I blogged about pricing strategies (see old posts here, here and here). I recently enjoyed listening to Soichi Nakajima, Director of "Digital Telco and OTT" at IDATE DigiWorld when he presented a talk on LTE pricing strategy. The slides are embedded below

Supply-side strategies: from LTE to 5G - IDATE from techUK

I think the slides are self-explanatory but here is the summary worth highlighting:

How LTE plans have changed: shift in focus from data allowance to quality of service 

• Mobile data services are still largely structured by on data allowance, but high volume and unlimited plans are increasingly common. 
• Unlimited does not necessarily mean high-end: some target users with a small budget, providing a very slow connection. 
• Quality of service becoming central in structuring product lines – especially speed which my or may not be combined with data caps – as is content quality. 
• Certain applications being favoured through zero rating (traffic not deducted from the customer’s allowance). This can be a way to market unlimited plans and avoid fixed-mobile substitution. 
• Growing number of partnerships with OTT video services, rather than selling premium content plans, which are tending to wane.

The slides are available to download from techUK page here. There is also a bonus presentation on "How to address the challenges of providing connectivity on trains".

Report on Spectrum Usage and Demand in the UK

Last week at work, we released a report titled "UK Spectrum Usage & Demand". The only time most people hear about spectrum is when there are some auctions going on. Often a small chunk of spectrum gets sold off for billion(s) of dollars/pounds and these surely make a headline. As I recently found out, 50% of spectrum in UK is shared and 25% is license exempt.

Anyway, this first edition of the report focuses on Public Mobile, Utilities, Business Radio and Space/Satellites. Space is becoming an important area of focus here as it is a significant contributor to the UK economy.

Anyway, the report is embedded below and is available to download from here:

LTE - Service Opportunities; threats and challenges for the Rail Industry

Interesting presentation:

LTE - Service Opportunities; threats and challenges for the Rail Industry

View more documents from Zahid Ghadialy

See Also:

• Wi-Fi in Public Transport over LTE

Wi-Fi in Public Transport over LTE

Another interesting presentation from the LTE World Summit 2011 on how LTE can be used as a backhaul in the trains to provide passenger WiFi and other services.

Uses for LTE in the Transport Vertical Market

View more presentations from Zahid Ghadialy