Seriously why the forget do phone carriers do this? These things NEVER work and they are forced upon you if you are on the bus or in a vehicle. They are practically an internet deadzone if you dare to forget to disable Wi-Fi as a whole because some demented handicap decided that you can't disconnect from the network so you won't get this loving tumour of a network leeching onto your phone and interrupting everything you do.
So yeah. forget mobile hotspots, they are actively a net negative and make everything worse