  We re-use some original ideas of de~Broglie, Schr\"odiger, Dirac and Feynman
to revise the ensemble interpretation of wave function in quantum mechanics. To
this end we introduce coherence (auto-concordance) of ensembles of quantum
trajectories in the space-time. The coherence condition accounts phases
proportional to classical action, which are in foundation of the Feynman path
integral technique. Therefore, our interpretation is entirely based on
well-known and tested concepts and methods of wave mechanics. Similarly to
other ensemble interpretations our approach allows us to avoid all problems and
paradoxes related to wave function collapse during a measurement process.
Another consequence is that no quantum computation or quantum cryptography
method will ever work if it assumes that a particular q-bit represents the
entire wave function.
