Abstract: A system and a method for communication between at least one user in a high-frequency HF communication system comprising at least one transmission site and at least one reception site, the two sites being remote from one another by a distance D, comprises at least the following steps: scanning the signals or frequencies by using a wide band receiver, detecting whether there is a request to establish a communication link contained in the signals received on the receiver, if yes, then transmitting this link establishment request to the transmitting equipment item which will check whether it is possible to establish a link and, if it is, which will determine a possible configuration and establish a communication mode for the mobile user, if not, then returning to the step in which the signals received on the reception site of the system are scanned.

Abstract: A method and system is provided for transmitting data in a communication system operating in the HF band comprising a link layer and a physical layer. The system comprises a transmitter and a receiver. The transmitter comprises at least one scheduler. The method comprises a step of segmenting at least two data streams F1,F2 each of the streams having a service constraint, each being segmented into a plurality of data sub-blocks FjBi, a step in which the data sub-blocks are transformed into a frame then a step of coding and interleaving the first frame TF1, and of the second frame TF2, producing sub-frames STF1c, STF2c, then generating a frame to be transmitted by mixing n sub-frames STF1c of the data stream F1 with m sub-frames STF2c of the data stream F2.

Abstract: A method for managing the HF frequencies in a broadband communication network, comprises the following steps: determining the range of passing frequencies for a user for a given link and SLA service; establishing the set of authorized frequencies S? in the transmission range of the user with the different power and modulation configurations for each frequency; analyzing the received spectrum in order to determine the frequency or frequencies already used and deciding, on the basis of their associated usage type, whether they must be excluded; for each possible frequency fl of the set S??, determining the necessary power , i=1 . . . N, j=1 . . . m for each of the m possible rate/waveform configurations, taking into account the power limit on each frequency fl; allocating the frequencies fl of the set S?? to the different users, their modulation and their power, by taking account of multi-carrier constraints.

Abstract: A system and method for communication resource allocation, a resource including a time slot and at least one associated channel, said channel including at least one transmit and/or receive frequency usable during said time slot, in a mobile meshed network including a first set of radio transceivers communicating with one another via radio links, at least one group, comprising a second set of at least one radio transceiver of said first set, said second set including a master transceiver in a master/subordinate relationship with all the radio transceivers of the second set, a central radio transceiver of the network belonging to said first set.

Abstract: A method for improving the HF band link establishment in a communication system including one or more transmit terminals and one or more receive terminals, at least one of the terminals having a broadband capability, comprises the following steps: creating call bands and listening bands according to the broadband transmit and/or receive capabilities, the minimum number of bands being suitable for covering the entire frequency plan; minimizing the number of bands and then maximizing the number of frequencies in each of these bands of size B; distributing the bands Bi in time by arranging the bands in descending cardinal-value order, and allocating a frequency fj to each band Bi; transmitting/receiving in broadband mode, by checking that the selected transmit frequencies are not already in use.

Abstract: A system for establishing and sustaining a broadband communication is provided wherein: the first master post is suitable for transmitting a known test sequence on a sub-band Bk to the second called post as soon as the said second called post acknowledges the receipt of a communication setup message on a frequency fi; the said second controller being suitable for determining quality scores on the Mk frequencies of the sub-band Bk and for transmitting the said values of quality to the first master post. The first master post is suitable for determining and for evaluating the capability of the sub-band Bk to respond to the SLA target service a sub-channel on the basis of the scores of qualities received, and for selecting the sub-band Bk which exhibits the required capability and thereafter for triggering the communication with the said second post. Application to HF broadband systems.

Abstract: A method and system of communication in a wide band high frequency HF communication system is disclosed. The system includes at least n communication channels, an interleaver common to the n communication channels, a means for determining the quality of communication of each of the n communication channels. At least the following information is introduced into the structure of the frame of the data at the level of an autobaud: an item of information about the modulation employed on each of the n communication channels chn, an item of information about the interlever common to the n communication channels, the corrector code FEC employed, the number of communication channels employed (n) as well as for each one its identifier idn. The modulation is chosen on channel n, a common coding and interleaving are operated on the n channels, and the information introduced in the shared autobaud is transmitted.

Abstract: A method and system is provided for dynamic allocation of power required on a number n with n greater than 1 of an HF communication system, comprising an amplifier of maximum total power and at least one step in which the power and/or the modulation is managed on all the n pathways of said system so as to optimize a given probability of error termed the operating point for a maximum bitrate under the constraint of the total power imposed by the operation of said system.

Abstract: A method and system are provided for reducing the peak factor in a multi-carrier communication system, the data being transmitted on m channels comprising, in the transmission of data in the form of a frame, a step in which a number d of desynchronization symbols are introduced at the start of each of the frames, the number d being chosen as a function of the transmission channel number concerned.

Abstract: A method of determining the coding parameters of a variable-resolution video stream by a video coder, said video stream including multiple resolution layers and being compressed so as to be transmitted at a given rate or a given quality through a heterogeneous network to multiple users, said method including a classification step to associate each resolution level with a group of users and to determine the optimal coding parameters for each resolution level as a function of the requirements of each group of users.

Abstract: A method and system is provided for transmitting data in a communication system operating in the HF band comprising a link layer and a physical layer. The system comprises a transmitter and a receiver. The transmitter comprises at least one scheduler. The method comprises a step of segmenting at least two data streams F1,F2 each of the streams having a service constraint, each being segmented into a plurality of data sub-blocks FjBi, a step in which the data sub-blocks are transformed into a frame then a step of coding and interleaving the first frame TF1, and of the second frame TF2, producing sub-frames STF1c, STF2c, then generating a frame to be transmitted by mixing n sub-frames STF1C of the data stream F1 with m sub-frames STF2C of the data stream F2.

Abstract: A method for adaptive communication in an HF frequency band includes at least one of the following steps: the determination of a payload subband S that is available for a transmission in the HF band, the selection in the payload subband S of a set of n frequency channels of identical width according to a frequency allocation plan and the quality of the link of each of said channels, or the simultaneous transmission on the n frequency channels of a signal complying with an HF waveform.

Abstract: A method for managing the HF frequencies in a broadband communication network, comprises the following steps: determining the range of passing frequencies for a user for a given link and SLA service; establishing the set of authorised frequencies S? in the transmission range of the user with the different power and modulation configurations for each frequency; analysing the received spectrum in order to determine the frequency or frequencies already used and deciding, on the basis of their associated usage type, whether they must be excluded; for each possible frequency fl of the set S??, determining the necessary power {tilde over (P)}ij, i=1 . . . N, j=1 . . . m for each of the m possible rate/waveform configurations, taking into account the power limit on each frequency fl; allocating the frequencies fl of the set S?? to the different users, their modulation and their power, by taking account of multi-carrier constraints.

Abstract: A method for improving the HF band link establishment in a communication system including one or more transmit terminals and one or more receive terminals, at least one of the terminals having a broadband capability, comprises the following steps: creating call bands and listening bands according to the broadband transmit and/or receive capabilities, the minimum number of bands being suitable for covering the entire frequency plan; minimising the number of bands and then maximising the number of frequencies in each of these bands of size B; distributing the bands Bi in time by arranging the bands in descending cardinal-value order, and allocating a frequency fj to each band Bi; transmitting/receiving in broadband mode, by checking that the selected transmit frequencies are not already in use.

Abstract: A system and method for communication resource allocation, a resource including a time slot and at least one associated channel, said channel including at least one transmit and/or receive frequency usable during said time slot, in a mobile meshed network including a first set of radio transceivers communicating with one another via radio links, at least one group, comprising a second set of at least one radio transceiver of said first set, said second set including a master transceiver in a master/subordinate relationship with all the radio transceivers of the second set, a central radio transceiver of the network belonging to said first set.

Abstract: A method and system of communication in a wide band high frequency HF communication system is disclosed. The system includes at least n communication channels, an interleaver common to the n communication channels, a means for determining the quality of communication of each of the n communication channels. At least the following information is introduced into the structure of the frame of the data at the level of an autobaud: an item of information about the modulation employed on each of the n communication channels chn, an item of information about the interlever common to the n communication channels, the corrector code FEC employed, the number of communication channels employed (n) as well as for each one its identifier idn. The modulation is chosen on channel n, a common coding and interleaving are operated on the n channels, and the information introduced in the shared autobaud is transmitted.

Abstract: A method and system is provided for dynamic allocation of power required on a number n with n greater than 1 of an HF communication system, comprising an amplifier of maximum total power and at least one step in which the power and/or the modulation is managed on all the n pathways of said system so as to optimize a given probability of error termed the operating point for a maximum bitrate under the constraint of the total power imposed by the operation of said system.

Abstract: A method for optimizing a video transmission, in a constrained environment using a video coder adapted for coding the video data to be transmitted, includes determining one or more compression parameters for the video coder considered to transmit the video data at a given throughput or for a given quality. The method defines and uses reference charts for the coder considered, and predicts for the part of the video sequence undergoing compression, using the reference charts, compression parameters to be used, such as the quantization interval, by selecting a chart for which the targeted range of throughput or of quality is the closest in distance to the part of the sequence to be compressed, while complying with a given margin, and updates with an iterative method the prediction step to converge on the best choice of parameterization. The iteration includes at least one compression step followed by a verification step, to compress the video data to be transmitted with the parameters.

Abstract: A method for protecting multimedia data encoded by the H.264 standard, the data being encapsulated in a structure of the network abstraction layer or NAL type, characterized in that the user inserts at least one redundancy NAL containing the error-correcting code used for transmitting the data.

Abstract: A system for establishing and sustaining a broadband communication is provided wherein: the first master post is suitable for transmitting a known test sequence on a sub-band Bk to the second called post as soon as the said second called post acknowledges the receipt of a communication setup message on a frequency fi; the said second controller being suitable for determining quality scores on the Mk frequencies of the sub-band Bk and for transmitting the said values of quality to the first master post. The first master post is suitable for determining and for evaluating the capability of the sub-band Bk to respond to the SLA target service a sub-channel on the basis of the scores of qualities received, and for selecting the sub-band Bk which exhibits the required capability and thereafter for triggering the communication with the said second post. Application to HF broadband systems.