  We develop two N=2 superfield formulations of free equations of motion for
the joint model of all D=4 massless higher-superspin fields in generating form.
The explicit Osp(2|4) supersymmetry is achieved without exploiting the harmonic
superspace, and with adding no auxiliary component fields to those of N=1
superfields. The formulations are developed in two different Osp(2|4)
homogeneous superspaces which have a structure of a fibre bundle over the
standard D=4 AdS superspace, with dimensions (7|4) and (7|8). The N=2 covariant
derivatives in these spaces are expressed in terms of N=1 ones which gives
simple rules for component analysis.
