Radio measurements of constant variation, and perspectives with ALMA
  The present constraints on fundamental constant variation (\alpha and \mu)
obtained in the radio range are reviewed, coming essentially from absorption
lines in front of quasars of intermediate to high-z galaxies, through CO, HI,
OH, HCO+, HCN .. lines up to NH3 and CII.
  With ALMA, the sensitivity to detect radio continuum sources in narrow bands
will increase by an order of magnitude, and the expected progress is
quantified. The relative advantage of the radio domain with respect to the
optical one is emphasized.
