Bottom Quark Mass Measurements at High Energies

Next-to-leading order (NLO) calculations in QCD taking mass effects into account have allowed to measure the b-quark mass at the M_z scale, assuming α_s flavour independence, and to test α_s universality, taking as an input the b-quark mass extracted at low scales, at LEP and SLC with data collected by DELPHI, ALEPH, OPAL and SLD.