The invention relates to a method and a device (1) for data transmission in a power supply network (power line communication). The device (1), preferably centrally located in a distribution box (6), is equipped with transceivers (3, 4, 5), each one of which is connected to a phasing line (11, 12, 13) of the power supply network, from which it can receive data, and to which it can transmit data. The transceivers are coupled via a control unit (2), wherein the control unit ensures that the data received from a phasing line can be transmitted, prepared, on at least one other phasing line. Hereby, a re-transmission on all phasing lines with the same transmission power, or a re-transmission matched to the particular signal strengths or the addressees of the data, can take place.