Study on feasibility of SATCOM for railway communication

Final Report
GEO / X-band
Criterion ID Criterion Evaluation Justification
CRT-TECH-10
CRT-TECH-11
The proposed satcom system shall support Data and Voice
services.
The proposed satcom system shall support as minimum Low
bandwidth applications
C
C
This solution is full IP and based on a DAMA scheme using DVB-S2X / RCS2
standards. Therefore, it will support all kind of IP services (voice and data).
With the correct dimensioning of the system, a GEO/X-band satcom solution is
able to provide railway critical narrowband applications.
CRT-TECH-12
The proposed satcom system for the FRMCS shall provide
“user-to-user” and “multi-user” types of communications for
both voice and data services. In addition, each communication
can be bi-directional or uni-directional with any type of
asymmetry between forward and return channels (when bidirectional).
C
Just like the previous GEO/C-band solution, this GEO/X-band solution is based on
DVB-S2X and DVB-RCS2+M standards, which allow most of the communications
types required except the multicast on the return link (i.e. the user to multi-user
from the remote terminal point of view). Therefore, an extra implementation at IP
level should be required to support this particular communication type.
CRT-TECH-13
The minimum required coverage of the satcom system shall be
Europe.
C
Just like previous solutions in S and C bands, this is a generic solution (based on
GEO/X-band satellite constellation in this case), which satellites should be
selected in order to provide full coverage to the pan-European area.
For example, GovSat-1 satellite, which launch date is expected for the third
quarter 2017, will provide coverage (among others) in X-band and also in Ka-band
(military reserved) to the pan-European area.
CRT-TECH-14
The satcom system shall provide communications for remote
terminals when stationary and when travelling at speeds up to
the maximum allowable line speed or 500 km/h, whichever is
the lower.
C
As it has been explained previously, the selection of the air interface has a
relevant impact on the error budget along with the frequency band (X-band). The
GEO satellite contribution to this error is negligible due to the use of very good
reference clocks and no movement of the satellite. Therefore, the use of
communications standards considering mobility effects and their compensations
(such as DVB-S2X and RCS2+M, for example), will enable high-speed
environments up to 500 km/h (or more).
Doc.Nº: SRAIL-FNR-010-IND
Edit./Rev.: 1/1
Date: 16/02/2017
Page 262 of 285