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 method and a system for transmitting data in a satellite system comprising at least one satellite, a gateway and a user terminal, comprises at least the following steps: transmitting a data content request Rq sent by a user to the gateway, upon receipt of the content of the request Rq, the gateway sends an order to the satellite so that the satellite transmits the content requested by the user to the user, the user acknowledges receipt of all or of at least a portion of this content to the gateway.

Abstract: A method of operating a satellite communication network is disclosed. The network includes a plurality of satellites interconnected by a plurality of satellite-to-satellite communication links. Each of the plurality of satellites is configured to communicate with at least one ground station using respective ground-satellite communication links. The method includes transmitting a routing table to each of the satellites. Each routing table has a list of destination satellites, and defines at least two possible routes leading to it. An alert message identifying a problem communication link is transmitted to a subset of the plurality of satellites. In response to receiving the alert message, subsequent data packets are routed through the communication network by the satellites using their respective routing table to avoid the problem communication link.

Abstract: A method of operating a satellite communication network is disclosed. The network includes a plurality of satellites interconnected by a plurality of satellite-to-satellite communication links. Each of the plurality of satellites is configured to communicate with at least one ground station using respective ground-satellite communication links. The method includes transmitting a routing table to each of the satellites. Each routing table has a list of destination satellites, and defines at least two possible routes leading to it. An alert message identifying a problem communication link is transmitted to a subset of the plurality of satellites. In response to receiving the alert message, subsequent data packets are routed through the communication network by the satellites using their respective routing table to avoid the problem communication link.

Abstract: 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.

Abstract: A soft handover method with gateway site diversity between a first nominal gateway to a relay satellite of a space telecommunication system and a second redundant gateway to the same satellite comprises a soft handover preparation phase, and a soft handover execution phase that are executed in succession. During the execution phase, a first switchover of the traffic at the ground segment level to the second redundant gateway, and a second switchover at the level of the segment on board the satellite between a first nominal access link of the first nominal gateway and a second redundant access link of the second redundant gateway are finely synchronized.

Abstract: A method of operating a satellite communication network is disclosed. The network includes a plurality of satellites interconnected by a plurality of satellite-to-satellite communication links. Each of the plurality of satellites is configured to communicate with at least one ground station using respective ground-satellite communication links. The method includes transmitting a routing table to each of the satellites. Each routing table has a list of destination satellites, and defines at least two possible routes leading to it. An alert message identifying a problem communication link is transmitted to a subset of the plurality of satellites. In response to receiving the alert message, subsequent data packets are routed through the communication network by the satellites using their respective routing table to avoid the problem communication link.

Abstract: An on-board method for the end-to-end transparent transport of data packets is implemented by a telecommunications system comprising a first, sending station, a second, receiving station, a first, sending satellite, connected directly to the first station, and a second, receiving satellite, connected directly to the second station, the first satellite and second satellite being interconnected via a spaceborne network. The transport method comprises steps allowing an end-to-end transparent adaptive control loop for the adaptive control of the modulation and of the coding of the access links between the first station and the first satellite and between the second station and the second satellite to be implemented.

Abstract: A method for transparent on-board routing of data packets at high bit rate is implemented by a telecommunication system comprising an origin transmitting station, a first destination receiving station, a second destination receiving station, and a plurality of at least two satellites. The origin transmitting station segments high bit rate data streams into coded or uncoded packets each having the structure of a coded or uncoded DVB-S2 baseband frame BBFRAME; and the origin transmitting station inserts, for each segmented BBFRAME packet, coded or uncoded, an on-board routing label of a single piece respectively associated with the coded or uncoded BBFRAME packet. The on-board routing label contains an identifier of the destination receiving station associated with the coded BBFRAME packet, out of the first destination receiving station and the second destination receiving station.

Abstract: A method of operating a satellite communication network is disclosed. The network includes a plurality of satellites interconnected by a plurality of satellite-to-satellite communication links. Each of the plurality of satellites is configured to communicate with at least one ground station using respective ground-satellite communication links. The method includes transmitting a routing table to each of the satellites. Each routing table has a list of destination satellites, and defines at least two possible routes leading to it. An alert message identifying a problem communication link is transmitted to a subset of the plurality of satellites. In response to receiving the alert message, subsequent data packets are routed through the communication network by the satellites using their respective routing table to avoid the problem communication link.

Abstract: A method for transmitting data between a terminal and a gateway, the data being transported by Ethernet frames comprising an Ethernet header and a payload, which are themselves encapsulated in lower level packets each comprising a header containing a medium access address, comprises the following steps: determining contexts common to frames whose Ethernet headers have identical fields, and defining an identifier of each the context; associating all or some of the frames with the corresponding context identifiers and suppressing the fields from their Ethernet headers; and introducing the context identifier of each frame for which the fields of the Ethernet header have been suppressed from the header of the lower level packet encapsulating it by replacing its medium access address. A method for receiving data transmitted by means of such a method.

Abstract: A method for transmitting data between a terminal and a gateway, the data being transported by Ethernet frames comprising an Ethernet header and a payload, which are themselves encapsulated in lower level packets each comprising a header containing a medium access address, comprises the following steps: determining contexts common to frames whose Ethernet headers have identical fields, and defining an identifier of each the context; associating all or some of the frames with the corresponding context identifiers and suppressing the fields from their Ethernet headers; and introducing the context identifier of each frame for which the fields of the Ethernet header have been suppressed from the header of the lower level packet encapsulating it by replacing its medium access address. A method for receiving data transmitted by means of such a method.

Abstract: A technique for configuring, in real time, an equipment item receiving and processing primary signals which are transmitted to it by satellite link, the technique including transmitting secondary signals with frequencies spread over a band at least partially overlapping a frequency band occupied by the primary signals, the secondary signals including signalling parameters which are used, in real time, by the equipment item to configure processing applied to the primary signals. The technique is applicable to dynamic switching of beams in a multi-beam satellite and to dynamic switching of frames, for example in a time-division multiple access system.

Abstract: The subject of the invention is a satellite comprising at least one central router, a source terminal and a destination terminal. The source terminal comprises means for transmitting, via the central router, IP packets fragmented into at least one level-2 fragment to the destination terminal to which a destination IP address is allocated. The said central router is composed of a satellite and of a ground router. The satellite comprises means for implementing a switching of the IP packets without reassembling the level-2 fragments sent by the source terminal to the destination terminal, the said fragments comprising a reference to the Destination IP address used as basis for the switching. The ground router comprises means for determining IP routing parameters, the said parameters being transmitted by the ground router to the satellite so as to configure the way in which the switching is carried out by the said satellite.

Abstract: A technique for configuring, in real time, an equipment item receiving and processing primary signals which are transmitted to it by satellite link, the technique including transmitting secondary signals with frequencies spread over a band at least partially overlapping a frequency band occupied by the primary signals, the secondary signals including signalling parameters which are used, in real time, by the equipment item to configure processing applied to the primary signals. The technique is applicable to dynamic switching of beams in a multi-beam satellite and to dynamic switching of frames, for example in a time-division multiple access system.

Abstract: A method for robustly transmitting a data flow in the form of packets Pi including at least one header Hi, said header being compressed via a first header compression step, said packets being fragmented into a succession of cells, said cells having an identical fixed size, said fragmentation resulting in the appearance of a padding section in the last of said cells, where the space occupied by said padding section is used, at least partially, to insert redundancy data, the function of said redundancy data being to increase the robustness to transmission errors of said compressed header.

Abstract: The invention relates to a method for the allocation of packets on a carrier containing timeslots, comprising the step of defining an interleaving length and an allocation window characterized in that packets are allocated within groups defined by the power needed for the transmission and that the size of groups is at most equal to the interleaving length.

Abstract: A satellite telecommunication system includes a plurality of user stations and at least one satellite. A resource manager for the satellite telecommunication system includes a congestion controller that assigns resources to uplinks, a demand assignment device that assigns resources to uplinks, and, for each satellite, a central entity that includes a subsystem of the congestion controller adapted to receive requests sent by user stations using the satellite, each request expressing the bit rate necessary for a group of connections supported by a user station and by the same downlink of the satellite, and to determine the bit rate authorized for the group of connections. It further includes, for each satellite, a subsystem of the demand assignment device adapted to allocate resources to an uplink, at each user station, as a function of the bit rates authorized by the congestion controller subsystem and globally for all connections supported by the user station.

Abstract: The invention relates to a method for the allocation of packets on a carrier containing timeslots, comprising the step of defining an interleaving length and an allocation window characterized in that packets are allocated within groups defined by the power needed for the transmission and that the size of groups is at most equal to the interleaving length.

Abstract: A satellite telecommunication system includes a plurality of user stations and at least one satellite. A resource manager for the satellite telecommunication system includes a congestion controller that assigns resources to uplinks, a demand assignment device that assigns resources to uplinks, and, for each satellite, a central entity that includes a subsystem of the congestion controller adapted to receive requests sent by user stations using the satellite, each request expressing the bit rate necessary for a group of connections supported by a user station and by the same downlink of the satellite, and to determine the bit rate authorized for the group of connections. It further includes, for each satellite, a subsystem of the demand assignment device adapted to allocate resources to an uplink, at each user station, as a function of the bit rates authorized by the congestion controller subsystem and globally for all connections supported by the user station.