I have one silly question

Hello , everyone !

           today when i wake up , my mind  click one question , what 

the range of band with for best energy detection based spectrum sensing

from my study of paper i came to know energy detection technique is best
for narrow band spectrum…but i could not find how much the band with
f t
…suggest me…if any buddy gone through the same problem

Thanks and regard:

MR.Maheshkumar P.
*call @ 9662784649