Emulation of end-to-end communications systems in railway scenarios: physical layer results

The complexity of modern communication systems is remarkable, and the efforts needed to put into service a new one are substantial as well. In some industrial sectors, circumstances are even harder. For example, in railways, the tests to be done are costly due to the integration in the rolling stock plus the need to have physical access to the railway tracks. Therefore, it is worth having a suitable emulator that considers many different radio-access technologies (RAT) in several railway scenarios (viaducts, tunnels, rural, hilly, etc.). Moreover, it should be able to do an end-to-end emulation, absolutely transparent for the application layer (this is, considering not only the physical layer but the network one as well). In this paper, we highlight the physical layer aspects considered in the construction of this emulator. Integration with the network layer is briefly mentioned, as well as the whole architecture.