We present a perturbative method of calculating the temperature-depend
ent correction, Delta G, to the Landauer conductance which is due to t
he inelastic electron-phonon scattering. The limits of applicability o
f these methods as well as the critical interval of temperature (and o
ther relevant parameters) on which the transition from the ballistic t
ransport to the Boltzmann-Drude transport occurs are discussed.