  Given the very accurate data from the BATSE experiment and RXTE and Chandra
satellites, we use the GRB 991216 as a prototypical case to test the EMBH
theory linking the origin of the energy of GRBs to the electromagnetic energy
of black holes. The fit of the afterglow fixes the only two free parameters of
the model and leads to a new paradigm for the interpretation of the burst
structure, the IBS paradigm. It leads as well to a reconsideration of the
relative roles of the afterglow and burst in GRBs by defining two new phases in
this complex phenomenon: a) the injector phase, giving rise to the proper-GRB
(P-GRB), and b) the beam-target phase, giving rise to the extended afterglow
peak emission (E-APE) and to the afterglow. Such differentiation leads to a
natural possible explanation of the bimodal distribution of GRBs observed by
BATSE. The agreement with the observational data in regions extending from the
horizon of the EMBH all the way out to the distant observer confirms the
uniqueness of the model.
