Method for very high throughput satellite data transmission

A method for transmitting data by satellite between a gateway station and user terminals, the data being transmitted to the satellite by the gateway station over an uplink (UL) in the form of a succession of frames and retransmitted by the satellite over a downlink (DL) to the user terminals, the retransmission of the data over the downlink (DL) being performed after modulation with a carrier frequency, said modulation and said carrier frequency being dedicated to the corresponding downlink (DL), the method consisting, in the gateway station:

• in segmenting, assembling and encapsulating the data in different successive basic frames, UL BB-Frames, that can be transmitted over the uplink, each basic frame, UL BB-Frame, comprising a header field UL BBHeader, dedicated to the uplink (UL), and a data field UL DATAFIELD to be sent over the uplink (UL), then
• in coding and in modulating the data of each basic frame, UL BB-Frame, to construct frames UL PL-Frames and
• in sending the UL PL-Frames over the uplink (UL),
• wherein the method further comprises:
• a first additional preprocessing step consisting, in the gateway station, in pre-segmenting the data as a function of the carrier frequency which is dedicated to the data on the downlink (DL) and in encapsulating the pre-segmented data in successive basic frames DL BB-Frames, that can be transmitted over the downlink, the encapsulation of each basic frame DL BB-Frame of the downlink consisting in adding a transport header DL BB-TH dedicated to the downlink, and
• a second additional step consisting, in the gateway station, in incorporating the different basic frames DL BB-Frames of the downlink, associated with their respective transport headers DL BB-TH, in the data field of the different basic frames, UL BB-Frames, of the uplink,
• wherein the transport header DL BB-TH of each frame DL BB-Frame of the downlink comprises instructions intended for an OBP processor mounted on board the satellite, the instructions comprising at least one identification parameter DL Id of a modulator/coder to be used on the downlink, an identifier of the carrier frequency to be used, a start parameter and an end parameter indicating the start and the end of the corresponding frame DL BB-Frame, and a length parameter of the corresponding frame DL BB-Frame,
• wherein when a frame DL BB-Frame has a length greater than the length of the data field available in the UL BB-Frame of the uplink, the first additional preprocessing step further consists, in the gateway station:
• in fragmenting the corresponding frame DL BB-Frame into several fragments, then
• in encapsulating each fragment with a corresponding transport header DL BB-TH, and
• the second additional step consists, in the gateway station, in incorporating the different fragments of the fragmented frame DL BB-Frame in different consecutive frames UL BB-Frames of the uplink,
• the transmission method further comprising, on board the satellite:
• in receiving the UL PL-Frames, in demodulating and decoding the data of the frames UL PL-Frames received to extract from them the UL BB-Frames then, from each UL BB-Frame,
• in extracting the fragments of DL BB-Frames and in reassembling the fragments to reconstruct the complete DL BB-Frames,
• in routing each DL BB-Frame to the modulator/coder corresponding to the identifier DL Id indicated in the specific header DL BB-TH of said DL BB-Frame, then
• in transmitting the modulated and coded frames over the downlink DL.