1. Railway domain and its functional subsystems

1.1 Electromagnetic constitution of the railway domain

From an electromagnetic standpoint, the railway industry is made up of several sub-assemblies. The electrical power supply, rolling stock and signalling control form the electrical triptych of the railway system, shown in figure 1 . Straddling this triptych and the surrounding world is the field of telecommunications (both internal to the rail system, including on-board communications, and external to the system). The environment outside the railway system must also be taken into account, both in terms of potential aggressors and potential victims.