Study on feasibility of SATCOM for railway communication

Final Report
CRT-MULT-1 All communication networks (e.g. satcom and terrestrial) of the future railway
communications architecture shall be packet-switched (PS), since all the applications supported
shall be IP based.
RATIONALE
According to network trends, the Next Generation Network (NGN) is packet based and uses IP to
transport every traffic type (signaling, data, voice and video). It means that all services of future
communication systems are going to be accessed by IP.
In addition, NGN concept separates applications from transport networks (bearers). This way,
from the application point of view it will not be important the selected bearer. Figure 97 shows this
new concept where several bearers are available and they are used depending on the type of
terminal and availability. The core transport network is based on IP and the services and
applications are agnostic to the bearer.
Services &
Applications
SERVICES
Conversational
Voice call
Video call
Chat
...
Messaging
E-mail
SMS/MMS...
IM (Instant
Messaging)
...
Content-ondemand
Browse
Broadcast
Streaming
Download
...
Transport &
Control
IP Network
Access
Fixed UMTS / LTE / 4-
GSM(-R) Satellite Wi-Fi ...
network 3G
5G
Users
Figure 97: NGN convergence
Figure 98 shows the NGN architecture defined by the ITU-T (recommendation Y.2012) [RD-16]. It
can be seen that applications are independent from the network and they are on the top of the
architecture. (Generic) Interfaces between elements are standardized to guarantee integration
between them (ANI (Application-Network Interface), UNI (User-Network Interface) and NNI
(Network-Network Interface)).
Doc.Nº: SRAIL-FNR-010-IND
Edit./Rev.: 1/1
Date: 16/02/2017
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