  We extend a recent approach to Deformed Special Relativity based on deformed
dispersion laws, entailing modified Lorentz transformations and, at the same
time, noncommutative geometry and intrinsically discrete spacetime. In so doing
we obtain the explicit form of the modified Lorentz transformations for a
special class of modified momentum-energy relations often found in literature
and arising from elementary particle physics. Actually, our theory looks as a
very simple and natural extension of special relativity to include a momentum
cut-off at the Planck scale. In particular, the new Lorentz transformations do
imply that for high boost speed ($V \sim c$) the deformed Lorentz factor does
not diverge as in ordinary relativity, but results to be upperly bounded by a
large finite value of the order of the ratio between the Planck mass and the
particle mass. We also predict that a generic boost leaves unchanged Planck
energy and momentum, which result invariant with respect to any reference
frame.
