  This article is concerned with time global behavior of solutions to focusing
mass-subcritical nonlinear Schr\"odinger equation of power type with data in a
critical homogeneous weighted $L^2$ space. We give a sharp sufficient condition
for scattering by proving existence of a threshold solution which does not
scatter at least for one time direction and of which initial data attains
minimum value of a norm of the weighted $L^2$ space in all initial value of
non-scattering solution. Unlike in the mass-critical or -supercritical case,
ground state is not a threshold. This is an extension of previous author's
result to the case where the exponent of nonlinearity is below so-called
Strauss number. A main new ingredient is a stability estimate in a
Lorenz-modified-Bezov type spacetime norm.
