Study on feasibility of SATCOM for railway communication

Final Report
Lots of manufacturers providing different types of HW solutions.
L-band user-link. It could imply omnidirectional antenna, reducing this way complexity,
maintenance and cost.
Although it is considered as narrowband system, the Inmarsat BGAN can achieve a
throughput of 492kbps. It means that it provides an extra bandwidth that could be used to offer
new future safety-critical applications, or even some non-safety critical applications with
low bandwidth requirements.
Available immediately
Programmed upgrades coming soon (Inmarsat Global Xpress I-5 satellites and ICE Inmarsat 6
satellites).
Figure 27: Inmarsat 4 (BGAN) satellites beams
Regarding the air interface, Inmarsat 4 is based on:
Signal waveform for Forward link – TDM – (to be completed)
Signal waveform for Return link – MF-TDMA – (to be completed)
Inmarsat 4 lifecycle is not aligned with the replacement of GSM-R starting at 2023. In this sense, it is
expected that next generation (i.e. Inmarsat 6) of Inmarsat systems can also offer a good solution for
providing safety communications to train communications.
Inmarsat announces recently that Airbus Defence and Space (Airbus) was awarded with he contract to
build the first two mobile communications satellites for Inmarsat‘s sixth-generation fleet. The contract
is for the construction of the two satellites, where Airbus deliver the first satellite, Inmarsat-6 F1 (I-6
F1), by 2020. Uniquely for Inmarsat, the sixth-generation fleet will feature a dual-payload with each
supporting both L-band and Ka-band services. The new satellites will represent a step change in the
capabilities and capacity of Inmarsat‘s L-band services.
This new constellation confirms its continued commitment to delivering advanced L-band services for
decades to come and to maximising the growth opportunities that they see in this spectrum. The new
satellites will provide significantly greater L-band capacity and will be capable of supporting a new
Doc.Nº: SRAIL-FNR-010-IND
Edit./Rev.: 1/1
Date: 16/02/2017
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