Description
The objective of this activity is to develop the necessary 5G New Radio (NR) ground segment prototypes for servicing the Future Railway Mobile Communication System (FRMCS) via satellite and demonstrate the capability with end-to-end in orbit testing.Targeted improvements:Ensure compliance to the FRMCS safety and performance requirements by demonstrating the feasibility of servicing via a satellite link, complementing the terrestrial network. Provide ETSI RT standardisation group with the required inputs for satellite.Description:The Future Railway Mobile Communication System (FRMCS), being a successor of the GSM-R system, is planned to be operational before GSM-R's predicted saturation in 2030. In this respect, ETSI (European Telecommunications Standards Institute) is already preparing the relevant FRMCS standard. In the frame of this work, satcom is established as a componentof the future system. More specifically, the integration of satcom to FRMCS was identified to be more straightforward when satcom is employing 5G NR, which is going to be the air interface for the terrestrial FRMCS access. Regarding the terrestrial FRMCS 5G NR access, live trials are planned by 2024, as it is targeted for the first stable version of FRMCS to be available for procurement by the beginning of 2025.To establish satellite with solid foundation in FRMCS, and to demonstrate its capability to service the terrestrial gaps of communication,it is essential that a similar activity will take place also for satellite. This activity will therefore validate with a real in-orbit demonstration the capability of satellite to service operational trains with FRMCS while using the 5G NR air interface. For this purpose, ground segment prototypes (i.e., modems on board trains and for gateways) will be designed via FPGA or SDR-based developments and validated initially in a lab environment and then on field versus the FRMCS requirements. Whenever possible, COTS RF/antenna equipment should be used for the purpose of this development. Both ForwardLink and Return Link will be considered to demonstrate the interactivity of FRMCS use cases. The best candidate satellite connectivity (in terms of orbit, frequency), as well as trains of different speeds and different local environments (e.g. rural, suburban, urban) will be considered, to exhibit the response of the satellite 5G NR link and its compliance to the FRMCS requirements over a plethora of scenarios characterised by different multipath, fading and interference conditions. In addition, switching between satellite and terrestrial 5G NR networks will be showcased to offer insight on the performance of the handover that takes place when the train transitions between coverages. Satellite switching willalso be demonstrated in case a satellite constellation is considered for the live trials.The outcome of the work will feed the ETSI FRMCS standardisation through the participation to the ETSI RT standardisation group.