Study on feasibility of SATCOM for railway communication

Final Report
the payload of communication satellites, which is then translated, amplified for broadcasting,
and then fed to the antenna for transmission.
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User terminals: embarked, handheld and fixed terminals used directly by the end
users (not only trains, but also staff, operation and control centres, etc.).
Gap filler: gateway that transforms the satellite signal to a terrestrial signal (and vice
versa) in order to provide coverage to those areas where there is not direct visibility to
the satellite.
Note: GF is a particular element for railway scenarios due to railway channel features
(like are tunnels, stations, etc). It enables the SATCOM system to be integrated with
land-based communication solutions in order to provide full coverage along the trip.
The Ground Segment or control segment consists of those elements on the ground that
manage the satellite resources and interfaces with the satellites (NCC and GES respectively).
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NCC (Network Control Centre) is the network entity responsible for performing the
satellite network control and management functions: defining frequency plans,
establishing service polices, receiving reports and alarms from the network elements,
and storing them to demonstrate regulation objectives fulfilment, etc.
GES (Ground Earth Station): The GES is the network entity in charge of providing
communication between the service providers (RBC in the railway domain) and end
users (trains, ground crew…) via satellites.
The WAN (Wide Area Network) function is to interconnect all the ground segment
entities (GES, NCC) with the railway elements in charge of monitoring and controlling
the whole network (RBCs, Control Centres…). WAN can be redundant in order to
increase the service availability and integrity.
Furthermore, it is also used to monitor, control and track the satellite and the payload it is
carrying. Commercial SATCOM control is performed by the system owner or operator.
Space Segment comprises the satellite constellation as well the launch facilities that are
needed to place satellites in orbit. It is worth mentioning that it could exist more than one
satellite constellation with different functionalities, such as for example one providing
communications (mission critical and/or non-critical) and another one for positioning purposes.
SATCOM services can be further broken down into fixed versus mobile services. Fixed SATCOM
services operate from a terminal on the ground at a fixed location, whereas mobile counterparts are
transmitted from a terminal that can be in motion or temporarily stationary at the time of
communication (such as a ship, aircraft or land vehicle). Mobile SATCOM services have traditionally
provided voice and low data rate services up to about 0.5 Mb/s but, more recently, services derived
from fixed satellite systems have become available offering more than 10 Mb/s.
4.1.2 Identification of key functional and technical SATCOM parameters
Taking into account the previous baseline SATCOM system defined, the following key functional and
technical parameters are identified:
Doc.Nº: SRAIL-FNR-010-IND
Edit./Rev.: 1/1
Date: 16/02/2017
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