Generally, you use the radio network from mobile phone to cell tower, and then fibre optic to the switches. Sometimes they use microwave line of sight for surface-to-surface connections where fibre doesn’t make sense, or is unviable (terrain, distance, cost, difficulty of laying fibre, etc.). It’s possible that there could be a satellite connection in the process, but unlikely unless you’re on an airplane, a ship, etc.
The GPS on the mobile phone definitely does use satellite (receive only though, no transmit).
They manufacture and sell the buses in Canada… There are BYD buses in operation in at least Toronto, Victoria, Longeuil, St. Albert and Grand Prairie (and probably more by now). https://en.byd.com/news/byd-opens-first-canadian-bus-assembly-plant/ If you’re in Montreal, there’s a decent chance you’ll see BYD E6 taxis.
There’s been rumors of the cars being prepped for general sale in Canada… but I can’t find any proof of that right now.