The correct answer is:
(d) Methods of spectrum reallocation
The study conducted by Toffler Associates in 2001 primarily addressed topics related to the future of wireless communications, focusing on aspects such as spectrum management, technological impacts of cognitive radio, and long-term strategies for spectrum sharing. These areas were central to understanding how spectrum could be more efficiently used and managed as wireless technologies evolved.
However, methods of spectrum reallocation (option d) were not a primary focus of this particular study. The emphasis was more on sharing spectrum dynamically and innovatively, rather than reallocating spectrum through traditional methods, which typically involves regulatory frameworks and reassignment of frequencies by governmental bodies.
So, the correct choice is (d) Methods of spectrum reallocation.