I’ve been inveighing against the misuse of spectrum metaphors for some time, but it took this quote to make me realize that the figure of speech at issue is really metonymy, not metaphor.
Metonymy is referring to something not by its name, but by something that is intimately associated with it (Wikipedia). Some examples:
The designers come up with the ideas, but the suits (worn by executives) make the big bonuses.
The pen (associated with thoughts written down) is mightier than the sword (associated with military action).
Freedom of the press (associated with the journalists and what they write) is an important value.
The White House (associated with the President and his staff) stood above the fray.
He bought the best acres (associated with the land measured in acres).
Both metaphor and metonymy substitute one term for another: metaphor by some specific similarity, and metonymy by some association. In spectrum language both are at work, for example in “Guard bands leave too many frequencies (or spectrum) lying fallow.”
Metonymy: Frequencies are associated with radio licenses
Metaphor: Radio licenses are like title to property
Metonymy: Property title is associated with the land to which it relates
Metaphor: Fallow land stands for any underused asset