The canonical solution in train/subway/metro systems seems to be full-length antennas that span the tunnel corridor. The cool solution would be base stations b

The canonical solution in train/subway/metro systems seems to be full-length antennas that span the tunnel corridor. The cool solution would be base stations built into train carriages that then uplink through some kind of backhaul. I think (but need to properly evaluate) that some Australian trains use something like this. EDIT: Nooope nope nope, horribly misread. https://goughlui.com/2014/03/23/random-post-railcorp-gsm-r-rollout-opal-stuff-and-other-observations/ https://goughlui.com/2014/03/23/random-post-railcorp-gsm-r-r...