Example Applications - RFID: Fundamentals and Applications in Contactless Smart Cards and Identification - page 351

13.5 Transport Systems

13.5.1 Eurobalise S21

Although Europe is moving closer together cross-border transport still presents an
obstacle to Europe's railways. Different signals and train security systems force trains to
incur the cost of carrying multiple sets of equipment on locomotives and tractive units.
It is often necessary to expend precious time changing tractive vehicles at the border,
burdening trains with a competitive disadvantage compared to flying or travelling by
road (Lehmann, 1996).
For this reason, the European Union is backing the purchase of a unified European
train security and control system, the ETCS (European Train Control System). The
ETCS will facilitate interoperable cross-border traffic and improve the competitiveness
of railways by implementing the latest train control technology.
The ETCS comprises four main systems:

• EURO-Cab A vehicle device, in which all connected elements are linked to

the secure vehicle computer EVC (European Vital Computer) by a special ETCS
bus system.

• EURO-Radio A GSM radio link between the vehicles and a radio centre by the

track, the RBC (Radio Block Center).

• EURO-Loop A system for linear data transfer over distances up to several hundred

metres. The system is based upon so-called leakage cable, i.e. coaxial cables for
which the sheathing is designed to be partially permeable to the electromagnetic
field. The frequency ranges of this application lie between around 80MHz and
1 GHz (Ernst, 1996). EURO-Loop is primarily used to transfer information for the
evaluation of discretely transmitted data.

• EURO-Balise A system for the discrete transmission of data. Depending upon

design, local data (location marking, gradient profiles, speed limits) or signal-related
data for the route are transmitted to the vehicle (Lehmann, 1996).

The Eurobalise subsystem is particularly important, because it is a crucial prerequi-
site for the full introduction of the ETCS. In January 1995, after lengthy experiments,
the technical framework data for the EURO-Balise were determined. It is an inductively
coupled RFID system with anharmonic feedback frequency.
The power supply to the system is taken from a passing tractive unit by inductive
coupling at the ISM frequency 27.115MHz. Data is transferred to the tractive unit at
4.24MHz, and the system is designed to reliably read the data telegram at train speeds
of up to 500 km/h. See Figures 13.19 and 13.20, and Table 13.3.
Four different balise types have been developed by Siemens:

• Type 1 transmits a permanently programmed telegram.

•

Type 2 transmits a telegram that can be programmed by the user via the contactless
interface. For example, this may be line data such as gradient and speed profiles.