The above picture is a summary of the spectrum that was agreed to be studied for IMT-2020 (5G). You can read more about that here. I have often seen discussions around how much spectrum would be needed by each operator in total. While its a complex question, we cannot be sure unless 5G is defined completely.
There have been some discussions about the requirements which I am listing below. More informed readers please feel free to add your views as comments.
