Abstract: A method for transmitting data in a power line communication network, the method being executed in a network node device configured so as to communicate in a plurality of separate frequency bands with a second network node device, the method comprising steps for selecting a transmission mode for transmitting in a frequency band called “extended frequency band” comprising at least two separate frequency bands chosen from among the plurality of separate frequency bands; distributing data to be transmitted in the extended frequency band into a plurality of groups of data, each group being assigned to just one of the at least two separate frequency bands; and transmitting the data in each of the plurality of groups of data in the separate frequency band to which the group is assigned, the step for distributing the data being carried out by a data interleaver.