Study on feasibility of SATCOM for railway communication
SRAIL-FNR-010-IND%20-%20FinalReport_v1.1_20170216
SRAIL-FNR-010-IND%20-%20FinalReport_v1.1_20170216
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Final Report<br />
Parameter<br />
Types <strong>of</strong> terminals<br />
Definiti<strong>on</strong><br />
Taking into account to the (<strong>SATCOM</strong>) communicati<strong>on</strong>s system, some different types <strong>of</strong><br />
terminals could be provided, such as:<br />
- Fixed terminals<br />
- Mobile terminals (i.e. <strong>on</strong>-board <strong>on</strong> trains - SOTM)<br />
- Portable (i.e. nomadic)<br />
- Handhelds<br />
Table 10: Satcom functi<strong>on</strong>al and technical parameters definiti<strong>on</strong><br />
4.2 MULTI-TECHNOLOGY COMMUNICATION ARCHITECTURE DESCRIPTION<br />
Previous secti<strong>on</strong> c<strong>on</strong>siders the use <strong>of</strong> a <strong>SATCOM</strong> system as the <strong>on</strong>ly <strong>on</strong>e communicati<strong>on</strong> system <strong>for</strong><br />
<strong>railway</strong>s. Due to its own nature, satellite visibility (coverage) is not always assured al<strong>on</strong>g the required<br />
area. For example, in the <strong>railway</strong> domain there are tunnels or shadowing areas due to buildings,<br />
trees… without satellite coverage. To solve this issue, gap fillers have been introduced.<br />
But there are scenarios in the <strong>railway</strong> domain where a priori seems to fit in better a terrestrial system<br />
than a satellite <strong>on</strong>e, such as <strong>for</strong> example cities, where the existence <strong>of</strong> <strong>SATCOM</strong> obstacles (buildings,<br />
stati<strong>on</strong>s, underground tunnels, etc), al<strong>on</strong>g with the high number <strong>of</strong> users and ―af<strong>for</strong>dable‖ deployments<br />
make terrestrial systems more reliable and simpler.<br />
At this point it is worth menti<strong>on</strong>ing that there are some other scenarios where a priori <strong>SATCOM</strong> system<br />
seems to be more advisable than terrestrial <strong>on</strong>es, like <strong>for</strong> example rural (remote) areas with small<br />
number <strong>of</strong> users where a terrestrial communicati<strong>on</strong> system deployment could be complex and too<br />
much expensive.<br />
For that reas<strong>on</strong>, and following the Next Generati<strong>on</strong> Network (NGN) c<strong>on</strong>cept (where several access<br />
networks can be available <strong>for</strong> different types <strong>of</strong> users), future <strong>railway</strong> mobile communicati<strong>on</strong><br />
architecture shall allow the coexistence <strong>of</strong> several access technologies, which will also be independent<br />
from the applicati<strong>on</strong>s.<br />
Figure 15 shows a complete communicati<strong>on</strong> architecture including both satellite and terrestrial<br />
systems in order to provide full coverage <strong>for</strong> the possible <strong>railway</strong> scenarios.<br />
Doc.Nº: SRAIL-FNR-010-IND<br />
Edit./Rev.: 1/1<br />
Date: 16/02/2017<br />
Page 55 <strong>of</strong> 285
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