Abstract: Data communication between two devices (11, 12) over the public powerline network (13) uses a multi carrier technology wherein a communication channel is divided into a plurality of subchannels by frequency division multiplexing. A partial power as part of the total transmission power and a partial rate as a fraction of the total data rate are assigned to each subchannel as follows: Initially, the same partial power is assigned to each subchannel and the S/N ratio of each subchannel is obtained. Starting with the subchannel of the lowest S/N ratio and proceeding to that of the highest S/N ratio, the following steps are performed for each subchannel: Firstly, the partial rate is assigned in accordance with the respective S/N ratio such as to result in a predetermined transmission error rate. The assigned partial rate is then quantised to an integral value.