Supplying high-speed TGV M trains with the optical fiber backbone for the 2024 Summer Olympic Games

Written by 

Antonio Sequeira

Vice President Market Manager Railway

In July 2018, the Board of Directors of SNCF Mobilities approved a firm order for over 100 of Alstom’s next-generation AVELIA HorizonTM very high-speed trains (called TGV M by SNCF). This order has been increased in summer 2022 by 15 additional trains destined to assure connections to Italy and Switzerland. This new generation of very high-speed trains aims to address the ambitious goals of competitiveness in the rail sector and profitability for SNCF.
The trains are due to be up and running across France in time for the 2024 Paris Olympic Games which will see over 9.7 million spectators visit 40 different competition sites across France, with a primary focus being Paris. The trains will play a key role in getting athletes, spectators, and delegates to where they need to be on time – but the service also aims to meet rising demand for high bandwidth services while on the move.
With this in mind, Alstom awarded HUBER+SUHNER a contract to design and supply the Internet Onboard System (IOB) optical fiber backbone and fiber optic assemblies to enable fast and reliable Wi-Fi and internet connections on-board trains.
The TGV M project was made up of two phases. The first phase saw the development of detailed fiber optic assembly designs that are compliant with Alstom’s specification. This was followed by the mass production of fiber optic assemblies for 115 trains, with delivery expected in the next ten years.
Following a previous experience which has shown limitations and weaknesses, Alstom needed to find a new provider who had a proven track record in this field and could supply a reliable, sustainable, and cost-effective onboard fiber optic backbone solution. It turned to HUBER+SUHNER to deliver this.
Even with the correct fiber optic solutions, fiber optic technology as a whole was still a relatively new concept for the Alstom engineering, quality and installation teams given their past experience with this technology. For this to work, HUBER+SUHNER needed to provide Alstom with high levels of support and knowledge transfer, whilst providing a solution that met a life-time expectation of 30 years, typical with solutions in the railways industry.
Drawing from past experiences in providing fiber optic cable systems for the high speed Trenitalia trains in 2016, HUBER+SUHNER supplied Alstom with a range of solutions that met the Alstom endurance program requirements. This included the well proven Q-ODC2 railway hardened connectors, Mulitimode 3 RADOX® Twinfix FO cables, and FO Inter-vehicle Jumper Systems.
The Q-ODC2 connectors supplied by HUBER+SUHNER proved to be the most important aspect of the partnership. Previously, Alstom had found that connectors from other competitors in this field had given them poor results. However, the HUBER+SUHNER Q-ODC2 connectors enabled a more cost effective, flexible, and resistant solution for higher capacity deployments of wireless infrastructure in communication applications.
Customised RADOX® inter-vehicle jumper systems were installed to connect carriages. These can not only withstand extreme weather conditions but are also unaffected by constant movements at high speeds.
SENCITY® Rail MULTI rooftop antennas and SENCITY® Rail OMNI-SR Slim 3x3 MIMO in-carriage antennas were also installed to ensure increased performance and reliable high-data-rate transmission for Wi-Fi and passenger information systems. In addition, HUBER+SUHNER has designed a customised kit of Radio Frequency filters made of Double GSM-R filter 873-925Mhz and Single High Pass band 2-13Ghz, which will prevent radio-frequency interferences between outside antenna from the various communication systems.
HUBER+SUHNER successfully designed a customisable fiber optic backbone compliant with Alstom’s requirements and passed the demanding FAI and Prototype evaluations. The fiber optic solutions installed have proven to be more efficient than copper wire solutions, with increased longevity, performance, and reliable high-date-rate transmission, whilst demonstrating excellent resistance and reliability, even in the harshest of environments. Simulations carried out by Alstom have showed that the fiber optic solutions can already handle up to 10Gbit of data bandwidth, thus the FO IOB backbone will not be a bottleneck for future improvements of IOB services.
The reliability of the fiber optic backbone products paves the way for selection of this technology on high-speed trains in the future. In addition, the jumper cables designed and produced as a result of this collaboration can now be used by other industry manufacturers to guarantee fast, stable and reliable onboard connectivity.