Validation of an LTE Backbone for Inter-Car Communications in Metro Environments

The introduction of wireless systems to replace wired communications inside trains is currently being faced by the railway industry. Guaranteeing a reliable communication link is a challenge due to the dynamic behavior of the radiofrequency (RF) propagation channel. In this paper, an experimental validation of a Long Term Evolution (LTE) communications system is presented for a metro train backbone. Wireless channels are measured and characterized in different metro scenarios, and a channel emulator is used to recreate the physical RF propagation conditions in laboratory. Two functional scenarios are validated: the train inauguration and the data exchange between consists. Obtained results indicate that Doppler spread mainly influences the LTE uplink, cutting throughput up to 40 %.