The fact that Century-bandwidth has a dash but decade bandwidth has not is weird, I didn't make the connection due to that (one sounded like a brand name, the other not)
The term "century-bandwidth" is always used in the article as a pre-noun adjective. The term "decade bandwidth" is not used that way. It's the difference between "a well-known author" and "an author who is well known".
The term "century-bandwidth" is always used in the article as a pre-noun adjective. The term "decade bandwidth" is not used that way. It's the difference between "a well-known author" and "an author who is well known".