how do they cut the wifi connection once I move in or out of the train?

Question

Specifically how do they cut the train’s station wifi’s connectivity once I am in the train and the train’s wifi’s network offers me to connect inside the train?

In: Technology

Answer 1

The train is a metal box. Any decently programmed OS will prefer to use the stronger signal, and the one that needs to go through a metal box won’t be it.