CONNECTA-3 · Project

Wireless Train Control Systems Ready for Real Rail Operations

transportPilotedTRL 7

projects.shift2rail.org

Imagine all the wires running through a train — connecting brakes, doors, engines, and safety systems. This project worked on replacing those physical cables with wireless communication, making trains smarter and easier to connect and disconnect like USB devices. They also built safety-critical networks reliable enough to handle braking by data alone, and tested everything on real lab demonstrators and at the InnoTrans 2022 trade fair. It's the third round of development, pushing these technologies from lab-tested to nearly deployment-ready at TRL 6/7.

By the numbers

TRL 6/7

Target technology readiness level for most developments

Consortium partners across 5 countries

86%

Industry partner ratio in consortium

SIL4

Safety integrity level for communication networks

Total project deliverables

Industry partners in the consortium

The business problem

What needed solving

Train manufacturers and operators are stuck with expensive, heavy wiring harnesses that limit flexibility — trains from different makers can't easily couple together, and certifying new safety-critical communication systems takes years and costs millions. Maintenance of wired train networks is a recurring cost drain, and every cable failure risks service disruptions.

The solution

What was built

The consortium built and validated wireless train backbone and consist network systems, SIL4-rated brake-by-wire communication networks, functional open coupling technology for multi-vendor train interoperability, and a virtual certification simulation framework. A physical demonstrator was showcased at InnoTrans 2022, with 17 deliverables completed across the project.

Audience

Who needs this

Rolling stock manufacturers (Alstom, Siemens Mobility, Stadler, Hitachi Rail)Urban transit authorities and metro operators upgrading fleetsRegional rail operators seeking flexible train formationsRailway signalling and safety system suppliersRail certification bodies and testing laboratories

Business applications

Who can put this to work

Railway rolling stock manufacturing

enterprise

Target: Train manufacturers and system integrators

If you are a rolling stock manufacturer dealing with complex and costly wiring harnesses that slow down train assembly and limit flexible consist formation — this project developed wireless TCMS and functional open coupling technologies validated at TRL 6/7 with 14 industry partners. The wireless train backbone eliminates physical cabling between cars, cutting assembly time and enabling trains to dynamically couple and decouple.

Urban and regional transit operations

enterprise

Target: Metro and regional rail operators

If you are a transit operator struggling with fleet flexibility and high maintenance costs for train communication systems — this project validated wireless consist networks and brake-by-wire technology at SIL4 safety levels for both urban and regional scenarios. These technologies allow mixing train units from different manufacturers and reduce cable-related maintenance failures.

Railway signalling and safety systems

mid-size

Target: TCMS and signalling equipment suppliers

If you are a rail safety systems supplier needing to certify next-generation communication networks — this project built a virtual certification simulation framework with hardware-in-the-loop testing and remote connectivity. This can dramatically reduce the time and cost of safety certification for SIL4 communication networks, demonstrated at InnoTrans 2022.

Frequently asked

Quick answers

What would it cost to adopt these wireless TCMS technologies?

The project data does not include specific pricing or licensing costs. However, as an Innovation Action with 12 industry partners including major rail OEM CAF as coordinator, the technologies were developed with commercial deployment in mind. Contact the consortium for pricing discussions.

Can these systems work at industrial scale on full train fleets?

The project targeted TRL 6/7, meaning technologies were validated in laboratory demonstrators and field tests for both urban and regional rail scenarios. A physical demonstrator was shown at InnoTrans 2022, the world's largest rail trade fair. Full fleet deployment would require final industrialization steps beyond TRL 7.

Who owns the IP, and how can we license this technology?

With 12 industry partners and only 1 research organization in the consortium, IP is likely held primarily by commercial entities. The coordinator CAF (Construcciones y Auxiliar de Ferrocarriles) is a major Spanish train manufacturer. IP and licensing terms would need to be negotiated directly with the consortium members.

Does this meet railway safety regulations?

The project specifically developed SIL4-rated communication networks — the highest safety integrity level for railway systems. The brake-by-wire and drive-by-data concepts were designed to comply with IEC 61375-2-6 standards for train-to-ground communication. Virtual certification tools were also developed to support the approval process.

How long before this can be deployed in real operations?

The project ran from December 2020 to November 2023 and is now closed. With most developments reaching TRL 6/7 and a demonstrator shown at InnoTrans 2022, the technologies are near deployment-ready. This was Phase 3 of the CONNECTA series, indicating mature development over multiple iterations.

Can these systems integrate with existing train fleets?

The Functional Open Coupling technology was specifically designed to enable interoperability between train units from different manufacturers. The standardized wireless protocols follow IEC 61375-2-6, and the Functional Distribution Framework was implemented using two different approaches (modified AUTOSAR and custom OS), showing adaptability to different platforms.

Consortium

Who built it

This is a heavily industry-driven consortium with 12 out of 14 partners (86%) from the private sector and zero universities — unusual for EU projects and a strong signal that these technologies are close to market. The coordinator, CAF, is one of Europe's major train manufacturers headquartered in Spain. Partners span 5 countries (Germany, Spain, France, Italy, Slovenia), covering the core European rail markets. With only 1 research organization and no SMEs, this is essentially an industry alliance building production-grade rail technology, not an academic exercise.

Construcciones y Auxiliar de Ferrocarriles, S.A.Coordinator · ES
DB SYSTEMTECHNIK GMBHthirdparty · DE
DEUTSCHE BAHN AGparticipant · DE
CENTRO DE ENSAYOS Y ANALISIS CETEST SLthirdparty · ES
CAF POWER & AUTOMATION SLthirdparty · ES
SIEMENS MOBILITY GMBHparticipant · DE
SLOVENSKE ZELEZNICE DOOparticipant · SI
KNORR-BREMSE SYSTEME FUR SCHIENENFAHRZEUGE GMBHparticipant · DE
ALSTOM TRANSPORTATION GERMANY GMBHparticipant · DE
FAIVELEY TRANSPORT ITALIA SPAparticipant · IT
ALSTOM TRANSPORT SAparticipant · FR
SNCF VOYAGEURSparticipant · FR
PROMETNI INSTITUT LJUBLJANA DOOthirdparty · SI
CONSTRUCCIONES Y AUXILIAR DE FERROCARRILES INVESTIGACION Y DESARROLLO SLthirdparty · ES

How to reach the team

CAF (Construcciones y Auxiliar de Ferrocarriles, S.A.) based in Spain — reach out to their innovation or R&D department

Order a report on this consortium See Construcciones y Auxiliar de Ferrocarriles, S.A. profile →

Next steps

Talk to the team behind this work.

Want an introduction to the CONNECTA-3 consortium? SciTransfer can connect you with the right technical contact for wireless TCMS, brake-by-wire, or virtual certification technologies.

Order a report on this topic More in Transport & Mobility