  We report new oscillations of wavepackets in quantum walks subjected to
electric fields, that decorate the usual Bloch-Zener oscillations of
insulators. The number of turning points (or sub-oscillations) within one Bloch
period of these oscillations is found to be governed by the winding of the
quasienergy spectrum. Thus, this provides a new physical manifestation of a
topological property of periodically driven systems that can be probed
experimentally. Our model, based on an oriented scattering network, is readily
implementable in photonic and cold atomic setups.
