The invention relates to a first network node and a second network node. The first network node being configured to communicate with a user device over at least two radio channels and comprising: a transceiver configured to receive a first sequence of data packets of a data flow addressed to the user device from a second network node; a processor configured to split the first sequence of data packets into at least one first sub-sequence of data packets and one second sub-sequence of data packets; wherein the transceiver further is configured to transmit the first sub-sequence of data packets in a first set of frequency resources over a first radio channel and the second sub-sequence of data packets in a second set of frequency resources over a second radio channel to the user device, wherein the first set of frequency resources and the second set of frequency resources are non-overlapping.