  Physical consistency of quantum fields in anti-de Sitter space time requires
that the space must be compactified by the inclusion of a boundary where
appropriate conditions are imposed. An interpretation for the presence of this
boundary is found taking AdS as a limiting case of the space generated by a
large number of coincident branes. The compactification of AdS leads to a
discretization of the spectrum of bulk fields. As a consequence, we find a one
to one mapping between the quantum states of scalar fields in AdS bulk and
boundary. Using this mapping as an approximation for the dual relation between
string dilaton field and scalar QCD glueballs the high energy QCD scaling is
reproduced. We also use this map to estimate the ratio of scalar glueball
masses.
