In June 2004, re-analysis of Oklo (in Gabon, West Africa) LANL nuclear reactor data finds that, the Fine Structure Constant (a) has decreased by 4.5 parts in 10⁸ in last 2 billion years (Phys. Rev. D, Vol. 69，P. 121701), that translates into a very small increase in the speed of light. This is the experimental situation against the classical special relativity (SR) recently, but there are problems of interpretation. In other-wise, for a massive photon the Maxwell equations get replaced by the Proca equations. And then, the magnetic veotor potential A becomes observable. There are old methods and recent mearements about the rest mass of photon, so we believe that, in fact the photon is massive.

The main, linear extensions of Maxwell equations are the Proca equations (1936) and the Ohmara equations (1956). The purpose of this paper is to study the EM-wave velocity in the Proca's theory frame. And it is found that there is superluminal speed of the electro-magnetic waves which propagate in the free-space (vacuum). In the paper, a comparison is made between the cut-off phenomenon of waveguide and the Proca waves, the significant results is presented.