Abstract:
A system for bidirectional data transmission in a telecommunication network comprises at least two distinct access networks to a mobile terminal, comprising at least one hybridation gateway that is configured to constitute an access point to each of the access networks, and to perform at least: control functions for all of the access networks, selection functions for the access network or networks selected for the data transmission, network layer functions, and data link layer functions, and wherein each of the access networks comprises at least one access gateway configured to perform at least physical layer functions.
Abstract:
A locating and communication method for a radio terminal by means of a satellite locating and communication system, which implements a first step, in the course of which the radio terminal transmits to a non-geostationary satellite a repeating sequence a predetermined number of times N for the same data packet, which is time-shifted by the same predetermined time shift Δτ each time is provided. Subsequently, a satellite access and processing ground station determines the location of the radio terminal from the data packets with access, which are extracted from a listening signal digitized and dated by the satellite and from the same detected sequence associated with said radio terminal, and from the ephemerides of the satellite by using a technique for measuring angle or angles of arrival by means of sequenced interferometry associated with a technique for measuring Doppler drift or drifts.
Abstract:
A method is provided for transmitting data between a first communication device and a second communication device, the first communication device being configured to receive from a router connected to the first communication device data in the form of packets comprising at least one intermediate level label, wherein the method comprises at least: a) an initial step of connection setup, comprising at least: a1) a sub-step of transmitting the intermediate level label; a2) a sub-step of recording the intermediate level label; b) a step of transmitting the data packet, comprising: b1) a sub-step of deleting the intermediate level label transmitted by the router connected to the first communication device in the data packet; b2) A sub-step of transmitting the de-encapsulated data packet, with a view to being reconstructed after its transmission.
Abstract:
A radiofrequency system and to a data collection method includes at least one beacon, and at least one space platform or airborne platform with an adaptable antenna beam. The method comprises: a step wherein the platform emits an activation signal with a low directional antenna beam, each beacon responding with an access request, a step of generating a table comprising, for each item of equipment, a duration of visibility, a frequency band and a transmission duration, a step of defining a control plan scheduling the sequencing of the transmissions associated with directional antenna beam configurations of the platform, a step comprising: transmitting the times at which they are able to transmit to the items of equipment that emitted an access request, orienting the antenna beam of the platform according to the control plan, sending and storing the data.
Abstract:
A data communication method between a mobile radio communications equipment and a gateway connected to a network, the data being organized in the form of packets comprising at least one first internal header and a second external header, comprises: an initial information exchange phase comprising: transmission by the radio communications equipment to the gateway of at least one predictable field out of the fields of the external and internal headers, reception by the radio communications equipment from the gateway of at least one predictable field of the external header, a phase of transmission of at least one data packet comprising: the deletion of the external and internal headers of at least one data packet, the generation, in at least one data packet, of a header of level lower than a network layer comprising at least one non-predictable field of the internal header, the transmission of at least one data packet.
Abstract:
An improved decoding method is provided making it possible to solve the problem of the error floor of a turbo-code or of an LDPC code, or more generally of a correcting code from the family of “turbo-like codes”, while preserving the same spectral efficiency, without any decrease in the useful throughput of the encoded stream. This result is obtained by an identification, on input to the decoder, of the bits on which an error has a strong impact, and a modification of the likelihoods corresponding to these bits so as to improve the convergence of the decoder.
Abstract:
A method of detecting and filtering illegitimate communication streams in a satellite communication network is provided, the method being executed by a gateway satellite station able to establish a communication link between a satellite and an access network and comprising the steps of: receiving a communication stream originating from the satellite, determining a set of characteristics of the communication stream forming a signature of the stream, applying at least one classification algorithm so as to class the signature into a set of legitimate signatures or into a set of illegitimate signatures, if the signature is classed into the set of illegitimate signatures, filtering the communication stream, otherwise transmitting the communication stream to the access network.
Abstract:
A method for synchronizing the transmission of messages in a communication system comprises a user terminal, a main communication network comprising a first station, and a secondary communication network comprising a second station, the method consisting of an exchange of synchronization signals to calculate an offset to be applied to the instant of emission of the messages transmitted by the second station so that the messages transmitted by the first station and the second station are received by the user terminal in a synchronous manner. A communication system implementing the invention is provided.
Abstract:
A method for transmitting data in a telecommunication network having a satellite component and a terrestrial component, the data being organized into a set of packets having an identifier, the telecommunication network comprising at least one bearer, at least one satellite and at least one terrestrial station, the method comprises the steps of: transmission of a data packet having an identifier from said satellite, reception of the data packet by the bearer, transmission of a data packet having an identifier in response to a transmitted negative acknowledgement message by the terrestrial station. A method for receiving data to be implemented on a bearer, a method for transmitting data to be implemented on a terrestrial station, and an associated data transmission system are also provided.
Abstract:
A method for optimizing the resources of a data transmission, based on a set of pairs of modulation and first correcting code, includes: determining, for each pair, maximum rate of a second correcting code applied to data transmitted before application of the first correcting code and of modulation wherein the error rate in data received is maximum a target error rate; the second correcting code applied at the medium access layer, to generate packets of redundancy bits based on packets of data bits received supplemented with padding sections, all having the same size; evaluating an item of information representative of the ratio between bits at input of the medium access layer and bits actually transmitted or of transmission bitrate required for solutions associating modulation, first and second correcting codes; selecting, from among solutions associating modulation, first and second correcting codes, to maximize the ratio or to minimize the transmission bitrate.