Determined by confirmed collocation in correct context. (See 
Comments below.)

Was looking for 電波占有率 and couldn't find it. Tried here 
and Space ALC for ideas on 占有率 by itself. Noted that JDICT 
didn't have "occupancy" as a gloss for 占有率, but that Space 
ALC did. Then Googled "channel occupancy" as a guess and got 
hits in the correct context. Returned here to add both 
"occupancy" for 占有率 and "(radio) channel occupancy" for 電
波占有率. That's how we often have to find things sometimes, 
but now the next guy/gal won't have to go to such lengths.