  The localization problem for massive fermions in the 5D standing wave
braneworld is considered. The fermion generations on the brane are explained by
the existence of three nodes of standing waves in the bulk, where the left and
right modes of the 5D fermion are localized and Dirac-type couplings mixes
them. We show that in this model the structure of peaks of the left and right
fermion wavefunctions in extra dimension leads to the observed mass spectrum of
the up and down quark families.
