Due to work traveling we have to put up with a location with quite "unstable" internet connection.
The property owner has set the charges including his own "wifi" facility providing to us.
Because the network is quite slow and unstable, we are not sure of it is a real broadband network or rather tethered from "his mobile" - you bet things like this can happen...
So how to identify the connection?
If you just want to tell if the connection goes through a tethered cell phone connection or a land (fixed) broadband connection, one way to try is to run a trace route. Once you know the path of your hops getting to the Internet, with little research and correlation you might just find out.