wifi sensitivity issue

Dear All:
         
           I have a question about wifi sensitivity caliculation.
         
           Our TIS sensitivity test result is -85dbm and I want to roughly caliculation by equation.
         SG(Pt=-30dBm)---TXANT(Gt=3dB) ---- AIR(Ploss=-50dB)----RXANT(Gr=5dB) ----DUT(Pr)
           By equation the sensitivity before RXANT is -83dbm,how is the totally sensitivity?
       ex: real sensitivity=-83dbm
             real sensitivity=-83dbm+5=-78dbm
             real sensitivity=-83dbm-5=-88dbm
       which one is correct?
       Thanks,