Partnering with ACKSYS: How SENCITY® Bridge MIMO antennas helped modernise an SNCF fleet

Written by 

Daniel Samo

Head of Product Management Wireless Connectivity


After twenty years of service operating across twelve regions across France and Luxembourg, SNCF Voyageurs launched a significant renovation program for their fleet of Regional Express Trains (TER). The project aimed to modernise the 931 sets the company had acquired between 2004 and 2011, which continued to make up 40% of their entire fleet. This included 699 High Capacity Railcars (AGC) and 232 TER 2 New Generation Level (TER 2N NG) sets.

To breathe new life into these train sets, SNCF wanted to incorporate new services such as passenger counting and enhanced Wi-Fi capabilities. The Train Digital-Market 6 tender was won by ACKSYS, a French manufacturer specialised in wireless communication solutions, enabling SNCF to supply new inter-carriage modules which would establish an inter-car Wi-Fi link. This would result in a complete on-board IP network, with each module consisting of two ACKSYS Wi-Fi access points (known as wireless couplers) installed within each of the sets.


Due to the age of the SNCF sets in use, many pieces of the equipment in operation required a major refurbishment. This included new equipment which would increase service efficiency and passenger safety. For example, the train driver’s rear-view was to be optimised with cameras connected to the onboard network. This would provide full visibility to the driver in order to check whether the train doors can be safely closed before departing a station.

For the inter-carriage coupling used on the trains, new antennas were required to best support the ACKSYS solutions made available for the project. ACKSYS needed a partner they could trust to deliver tailored technologies that would enable the development of the on-board IP network. Any antenna provider joining the project would also need to be able to meet the stringent protection requirements set out by SNCF.


After previous successful collaborations between HUBER+SUHNER and ACKSYS regarding inter-carriage solutions, we were brought on-board to the project in late 2021. HUBER+SUHNER were well-known to SNCF as an antenna supplier, making us a suitable partner for the renovation process.

The SENCITY® Bridge MIMO 3x3 antenna was developed specifically for the application of inter-carriage coupling. Designed precisely from the outset to be compatible with ACKSYS Access Points, our antenna matched the required number of Wi-Fi channels, supported the relevant frequency bands and, crucially, offered the necessary form factor for inter-carriage installation.

Operating on the 5 GHz band and supporting up to 3x3 MIMO, the antenna has built-in attenuators which ensure the radiation pattern of the system is specifically limited to the area between the carriages. This ensures a secure, reliable link between the train cars without the threat of interference from other vehicles or devices nearby.

The antenna was also developed to meet the stringent requirements for railway fire protection and relevant environmental standards. This meant it could be relied upon once the trains were ready to enter service for another 15 years minimum.


Thanks to the tailored antenna solution and support provided by HUBER+SUHNER throughout the project, the ACKSYS solutions are now being successfully utilised in the SNCF refurbishment project.

The first SNCF train sets have now been equipped with modern inter-carriage modules, underpinned by the SENCITY Bridge MIMO antennas. Though only a third of the way through the project, these optimised trains will be used across the Grand Est, Occitanie, PACA and CVDL regions once back in service.

As a result of the project, the drivers using the SNCF trains will be able to trust they can close doors securely without unnecessary risk. Operators will also have the tools to accurately track footfall and gauge the true capacity of the train, ensuring a safer service for their commuters. Following the success of the project, HUBER+SUHNER look forward to further collaborations with both SNCF and ACKSYS in the future.


SENCITY® Bridge MIMO 3x3 Antenna 85109045 Wi-Fi MIMO 3x3 antenna designed for Railway Inter-carriage communication