A method comprises a preprocessing step consisting, in the gateway station, in pre-segmenting the data as a function of the carrier frequency which is dedicated to them on the downlink DL, in reassembling and in encapsulating the pre-segmented data in successive basic frames DL BB-Frames, that can be transmitted over the downlink, each basic frame DL BB-Frame of the downlink being encapsulated by addition of a specific transport header DL BB-TH on the downlink and a data field, and a step consisting, in the gateway station, in incorporating the different basic frames DL BB-Frames of the downlink in the data field of the different basic frames UL BB-Frames of the uplink.