  We address the issue of gravitational radiation in the context of the
Bondi-Sachs space-time, and consider the expression for the gravitational
energy of the radiation obtained in the realm of the teleparallel equivalent of
general relativity (TEGR). This expression is independent of the radial
distance (i.e., of powers of $1/r$) and depends exclusively on the functions
$c(u,\theta,\phi)$ and $d(u,\theta,\phi)$, which yield the news functions ($u$
is the retarded time, $u=t-r$). We investigate the mathematical and physical
features of this energy expression in the simpler framework of axial symmetry.
Once a burst of gravitational radiation takes place in a self gravitating
system, that leads to a loss of the Bondi mass, gravitational radiation is
emitted throughout the whole space-time. The existence and presence of this
radiation in the background structure of the space-time is consistent with the
analysis developed by Papapetrou, and Hallidy and Janis, who found no proof
that a gravitational system that emits a burst of gravitational radiation is
preceded and followed by two stationary gravitational field configurations,
namely, it seems that it is impossible for a gravitational system, which is
initially stationary, to return to a stationary state after emitting a burst of
axially symmetric gravitational radiation, in which case the space-time is not
even asymptotically stationary. Therefore, it is plausible that the
gravitational energy of radiation is present in the background structure of the
space-time, and this is the energy predicted in the TEGR. This analysis lead us
to conjecture that the noise detected in the large terrestrial gravitational
wave observatories is intrinsically related to the background gravitational
radiation.
