I've noticed that our new Trams here in Edinburgh have a much difference free wifi service to what the busses have. Firstly it's not provided by 3G/4G like the busses (Vodafone)
But by an ISP called Custodian, which I've never heard of.
There is no separate cables or antennas on the electric poles/lines, nothing at track side like masts or antennas.
So just how are they providing a service to them which has a latency of 6-7 ms with speeds up to 20 both ways over wifi. Any ideas?