Cosmological observations over the decades favour our universe with a positive cosmological constant. Even a tiniest value of positive cosmological constant profoundly alters the asymptotic structure of space-time, forcing a re-look at the theory of gravitational radiation. In particular, we discuss the surprising consequences of gravitational radiation theory in Bondi-Sachs formalism. We also generalize Bondi et. al's celebrated mass-loss formula in presence of positive cosmological constant.