Abstract: A data transmission system in a communication network comprising a data modulator comprises: a first part at the level of the collection point part comprising: an NCR module taking account of an external absolute time reference to reconstitute a network clock, a transmitter module receiving the value of a time reference to be inserted into the data packet to be transmitted and transmitting to the NCR module an information item on an instant of synchronization for the receiver, a second part at the level of the radiofrequency part of a gateway comprising; a receiver module, a module for reconstructing a clock locally, a module for inserting a time reference into a data packet received by the receiver before transmission of the data via the satellite, the first part and the second part exchange encapsulated data.

Abstract: A ground station with P antennas for individually tracking a satellite out of an origin first moving satellite S1 and a destination second moving satellite S2 comprises, connected in series, a multi-channel reception and processing device and a combination device with configurable diversity, and comprises a device for managing diversity and seamless handover of a reception communication link from the origin first satellite S1 to the destination second satellite S2.

Abstract: A ground station with P antennas for individually tracking a satellite out of an origin first moving satellite S1 and a destination second moving satellite S2 comprises, connected in series, a multi-channel reception and processing device and a combination device with configurable diversity, and comprises a device for managing diversity and seamless handover of a reception communication link from the origin first satellite S1 to the destination second satellite S2.

Abstract: A data transmission system in a communication network comprising a data modulator comprises: a first part at the level of the collection point part comprising: an NCR module taking account of an external absolute time reference to reconstitute a network clock, a transmitter module receiving the value of a time reference to be inserted into the data packet to be transmitted and transmitting to the NCR module an information item on an instant of synchronization for the receiver, a second part at the level of the radiofrequency part of a gateway comprising; a receiver module, a module for reconstructing a clock locally, a module for inserting a time reference into a data packet received by the receiver before transmission of the data via the satellite, the first part and the second part exchange encapsulated data.

Abstract: An antenna with polarization switching comprising a plurality of waveguides fed with radiofrequency signals and perforated with apertures disposed so as to illuminate radiating elements placed on mobile support means in a plane that is distant from the said apertures, it being possible for the said support means to be configured according to at least two distinct configurations. The radiating elements illuminated according to one and the same configuration are adjacent, the support means being adapted for orienting the radiating elements illuminated in a first configuration according to a different direction from the radiating elements illuminated in a second configuration. The antenna applies notably to the switching of antennas onboard objects moving on the ground required to undertake high-speed communications with a satellite, in particular a geostationary satellite.

Abstract: An onboard directional plane antenna comprises at least one array of radiating-slot waveguides comprising an alternating succession of three superposed metallic plates and of two dielectric substrates. The two substrates each comprise at least four adjacent waveguides, corresponding and communicating with one another pairwise by way of coupling slots. Each waveguide of the upper substrate furthermore comprises a plurality of radiating slots passing through the upper metallic plate, all the radiating slots of one and the same waveguide being parallel to one another and oriented in one and the same direction, the radiating slots of two adjacent waveguides being disposed in chevrons. Each waveguide of the lower substrate comprises an internal individual feed circuit comprising an individual electronic circuit for phase shifting and amplification.

Abstract: An onboard directional plane antenna comprises at least one array of radiating-slot waveguides comprising an alternating succession of three superposed metallic plates and of two dielectric substrates. The two substrates each comprise at least four adjacent waveguides, corresponding and communicating with one another pairwise by way of coupling slots. Each waveguide of the upper substrate furthermore comprises a plurality of radiating slots passing through the upper metallic plate, all the radiating slots of one and the same waveguide being parallel to one another and oriented in one and the same direction, the radiating slots of two adjacent waveguides being disposed in chevrons. Each waveguide of the lower substrate comprises an internal individual feed circuit comprising an individual electronic circuit for phase shifting and amplification.