Study on feasibility of SATCOM for railway communication

Final Report
Satcom System
(Railway oriented)
Forward link
Comms
Standard
Return link
Space
Segment
Ground
Segment
User
Segment
Satcom
constellation
GES
User
Terminal
GNSS
constellation
NCC
Gap Fillers
WAN
Figure 14: Baseline satellite system high level breakdown
Figure 14 shows the satellite railway architecture, which is broken down in three main segments:
User Segment
Ground Segment
Space Segment
Besides, in Figure 14 a communication standard (CS) element has been included between the satellite
system and its segments, because the final selection of the CS on forward and return channels can
affect the selection and/or configuration of the different segments.
Below is presented a brief description of the understanding for each segment in a potential railway
satellite system architecture, including also the CS.
The Communication Standard defines completely the waveform to be used in both ways,
forward and return channels.
o
o
Forward Channel: defines the physical layer from hub to users
Return Channel: defines the physical layer from users to hub
The User Segment or terminal segment consists of the infrastructure to access satellite
signals. It covers the equipment on the land, at sea or in the air, used for transmitting and
receiving signals between the ground and communication satellites. These terminals access
Doc.Nº: SRAIL-FNR-010-IND
Edit./Rev.: 1/1
Date: 16/02/2017
Page 51 of 285