Introduction
Mobility is an important factor for the economic growth. Enhancing train transportation will become a key issue, as competing transportation means, like road and air, are gradually becoming saturated in capacity. The European Union tries to promote this by developing initiatives and enhancing the competitiveness of the rail grid by means of deregulation and interoperability, supporting this process with a planned upgrade to the existing rail network, the ‘Trans-European Net’ [1]. This will require the upgrade of 40,000 km of existing rail tracks for use at speeds up to 200 km/h instead of 160 km/h today and the development of 20,000 km of new rail tracks for use at speeds greater than 230 km/h. In this framework, some companies in Europe aim to develop new functionalities for trains.