  We establish the classical wave equation for a particle formed of a massless
oscillatory elementary charge generally also traveling, and the resulting
electromagnetic waves, of a generally Doppler-effected angular frequency $\w$,
in the vacuum in three dimensions. We obtain from the solutions the total
energy of the particle wave to be $\eng=\hbarc\w$, $2\pi \hbarc$ being a
function expressed in wave-medium parameters and identifiable as the Planck
constant. In respect to the train of the waves as a whole traveling at the
finite velocity of light $c$, $\eng=mc^2$ represents thereby the translational
kinetic energy of the wavetrain, $m=\hbarc\w/c^2$ being its inertial mass and
thereby the inertial mass of the particle. Based on the solutions we also write
down a set of semi-empirical equations for the particle's de Broglie wave
parameters. From the standpoint of overall modern experimental indications we
comment on the origin of mass implied by the solution.
