ERA * UNISIG * EEIG ERTMS USERS GROUP
SUBSET-026-2
3.0.0
23/12/08
System Requirements Specification
Chapter 2
Basic System Description
Page 3/22
2.2 Table of Contents
2.1
Modification History........................................................................................................... 2
2.2
Table of Contents.............................................................................................................. 3
2.3
Introduction ....................................................................................................................... 4
2.3.1
Scope and purpose....................................................................................................4
2.4
System structure ............................................................................................................... 5
2.5
Sub-systems .....................................................................................................................6
2.5.1
Trackside subsystem .................................................................................................6
2.5.2
On-board sub-system ................................................................................................7
2.5.3
UNISIG ERTMS/ETCS reference architecture ...........................................................8
2.6
Levels and transitions ....................................................................................................... 9
2.6.1
Introduction ................................................................................................................9
2.6.2
Definitions ..................................................................................................................9
2.6.3
ERTMS/ETCS Application Level 0 ...........................................................................11
2.6.4
ERTMS/ETCS Application Level STM......................................................................13
2.6.5
ERTMS/ETCS Application Level 1 ...........................................................................15
2.6.6
ERTMS/ETCS Application Level 2 ...........................................................................18
2.6.7
ERTMS/ETCS Application Level 3 ...........................................................................20
2.6.8
Level transitions.......................................................................................................22
