Railway communications

FRMCS

After more than 20 years of GSM-R success story, FRMCS and the 3GPP MCx framework pave the evolution path towards the next-generation of rail mobile communication. Not only have major railway companies engaged themselves in first MCx and FRMCS pilots and field trials, but also private railway operators have also started to leverage the advantages of MCX technology within their networks.

A key design goal of FRMCS is high reliability – transporting hundreds of thousands of passengers and tons of freight every day using rail lines that crisscross countries and continents requires a system that cannot be allowed to fail, and FRMCS is designed to be as robust as it can possibly be to avoid network outages by using two independent rail mobile radio (RMR) bands.

Typically, GSM-R was implemented using dedicated base station masts close to the railway tracks, with tunnel coverage provided by directional antenna or leaky cable (a cable that it has gaps or slots in its outer conductor to allow the radio signal to leak into or out of the cable along its entire length). The base stations are deployed at regular intervals along the railway lines, creating a high degree of redundancy, availability and reliability. But despite all its obvious strengths, GSM-R can never reach the capacity required by video surveillance and autonomous train operations.

5G and FRMCS will increase the number and type of use cases and services offered, allowing for the transfer of vast amounts of data that will enable driverless trains. The better communications provided by FRMCS means that the density of trains can be increased, allowing for more engines and carriages to use the rail network at any given time without interruption or disruption.

Future Railway Mobile Communication System (FRMCS) is the future worldwide telecommunication system designed by UIC, in close cooperation with the different stakeholders from the rail sector, as the successor of GSM-R but also as a key enabler for rail transport digitalisation.

The European railways currently use the GSM-R system for operational communication, a key component of the European Railway Traffic Management System ERTMS.

Designed 20+ years ago by UIC and completely border-crossing interoperable, GSM-R, which is a 2G+ based system, is deployed on more than 130,000 kilometers of track in Europe (with 90.000 activated On Board Cab Radio’s), and some 210,000 kilometers worldwide.

The Future Radio Mobile Communication System (FRMCS) is the Railways response for two elements of strategic importance for the future of the railways:

First – the fast-coming GSM-R obsolescence, which is European level risk for Railways ERTMS continuity (2035);

Second – it is also a significant opportunity, which is to enable and support the Railways Digitalization, and therefore the need to transmit, receive and use increasing volumes of data, which is at the very heart of sustainable transport.

https://youtube.com/watch?v=R4viEXd2VzU%3Fsi%3DSMr4Je9C_u7rNaZI

The UIC FRMCS activity is governed via below working groups:

  • The FRMCS Steering Group leads the global FRMCS strategy and planning,
  • The FRMCS Functionality Working Group (FWG) ensures the adequate matching between system functionalities and railway needs,
  • The FRMCS Architecture and Technology Group Working Group (ATWG) has the mission to define the FRMCS architectures, and the system requirements,
  • The FRMCS Telecom On-Board Architecture has the mission to define the On-Board FRMCS that uses the acronym (TOBA architecture) and functional requirements.
  • The UIC Group for Frequency Aspects (UGFA) takes care of the expected needs for spectrum, particularly sensitive in the transition scenarios.
  • FRMCS FIS (Functional Interface Specifications), defining the call flows to determine any gaps or inconsistencies,
  • FRMCS FFFIS (Form-Fit-Functional Interface specification), defining the On Board and Track Side Applications interface, responsible with the definition of the FRMCS border interface specifications,

These working groups are interfaced with UNITEL, ERA, and ETSI TC RT.

The missions of these groups also encompass the following key activities:

  • Build and deliver the FRMCS specifications:
    • FRMCS FRS
    • FRMCS SRS
    • FRMCS TOBA FRS
    • FRMCS FIS
    • FRMCS FFFIS
  • Obtain dedicated frequencies for FRMCS in Europe

The build and delivery of the FRMCS Specifications follows the European Process, as they are meant to be introduced in CCS TSI.

The FRMCS specifications will be completed with ETSI Technical specifications, delivered by the ETSI Railway Telecom technical committee.

FRMCS migration
FRMCS antennas

The deployment of FRMCS will require rail operators to increase the number of antennas they need, so there is a strong desire on their part to ensure that such installations are quick and relatively simple. The compact design of Ericsson’s new antenna utilizes a 100 percent recyclable radome, resulting in a unit that weighs less than 20 kilos – one engineer can transport a unit to the site and install it.

Optimized for the new 1900-1910 MHz band used by FRMCS TDD, the antenna features four cross-polarized columns for efficient spectrum usage and an integrated calibration port to enable beamforming. The new antenna can use electrical downtilt, and it can either be adjusted locally or by adding a control unit it can be adjusted remotely.

The antenna is not the only change that Ericsson is planning for FRMCS – a new FRMCS radio is currently being designed to work together with this antenna. The planned FRMCS radio will support 8T8R (eight transmitters and eight receivers), for frequency band n101, the allocated frequency band for rail in 1900-1910 MHz. Using phase synchronization, the radio and antenna will allow horizontal beamforming. This means that the beam can follow the train along a curve and will dramatically improve throughput. Furthermore, additional antenna types with both FRMCS and GSM-R capabilities are planned, helping railway operators to have both capabilities available in one single antenna. This can be useful when upgrading existing sites to keep GSM-R capability and preparing for FRMCS.The antenna is also aligned with the new radio unit in terms of number of ports and the frequency it caters for.

FRMCS v2
MCX solutions
Kontron MCX

https://www.kontron.com/ktrdn/mcx-solutionKontron Transportation is developing the MCx and 5G based FRMCS solution for Main Lines that need to build their own infrastructure. The private 5G networks of the main lines are used as transport medium for the MCx application with GSM-R features such as single call, group call and train emergency call.For Secondary Lines, which cannot build their own infrastructure due to high investments in infrastructure,  Kontron Transportation has developed the MCx OTT (Over The Top) solution. Here, the networks of the public providers are used as transport medium for the own MCx application with GSM-R features.Both solutions are based on the future FRMCS standardization (3GPP, ETSI). The Kontron Transportation MCx solution extends obsolete analog radio communication means with modern “state of the art” train radio functionalities, without the need to develop an own infrastructure.Kontron offers the solution as a “hosted solution” in a data center or as a server solution in the railroad’s own IT departments. Private 5G IP-68 industrial-grade smartphones with an MCx client, IP-enabled dispatchers with several modern user interfaces, and private 5G capable cab radios, that follow the FRMCS standard, serve as end devices.

A unique heart-beat function was developed, which allows the client software to be in constant contact with the application. This has the advantage that, for example, the user in the railcar or on the locomotive can see at a glance whether he is connected to the MCx application on the server or whether he is in a “dead zone”.

For the MCx OTT solution for Secondary Lines the heart-beat function serves as an addition to the use of two SIM cards from different providers in the end devices. Optionally or on request, it is thus possible to switch automatically between the network providers. If no data connection is available in both networks, an emergency call via GSM is possible in case of emergency.

This functionality goes beyond the current FRMCS standard and offers further security in train-to-land communication.

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