Abstract: The invention relates to a method of estimating symbols carried by a digital signal that is received by a receiver over a communication channel (5), said symbols being multiplexed or orthogonal frequency sub-carriers. The inventive method comprises the following steps in relation to each symbol carried by the digital signal, consisting in: performing at least two transforms towards the frequency domain (8,9) on a portion of the received signal essentially corresponding to the symbol, said transforms being performed with a determined time lag (10) therebetween: estimating the parameters (r0, r1, . . . , rn, r?0, r?1, . . . , r?n) of the communication channel from pre-determined binary information contained in the digital signal; and estimating the symbol from a combination of the result of each of the transforms performed and the estimated communication channel parameters.

Abstract: An onboard device for receiving a signal coming from an aircraft at a distance d from the device, said signal resulting from the combination of multiple propagation paths, one of the paths corresponding to the main echo of the transmitted signal, said device including an equalizer of processing depth T. The device includes means for estimating the distance covered by the second path, means for deducing therefrom a delay value ? associated with it, means for estimating when ? is greater than or equal to T the interfering signal associated with the main echo and for reducing the contribution of said signal to the total level of interference received. Also a system of communication between aircraft using the onboard device.

Abstract: The invention relates to transmission from a base station to a receiver, the base station comprising first radiating means arranged for transmitting according to an antenna pattern with respect to the receiver and further comprising second radiating means arranged for transmitting according to the same antenna pattern as the first radiating means with respect to the receiver, the transmissions of the first and second radiating means being time shifted by a determined duration.

Abstract: An antenna system includes at least one antenna and one X-Y mount, said mount being composed of at least three mechanical elements, the first element being a base, the second element being a lower box, the third element being a upper box, the antenna of the system being fixed to the upper box. The components of the antenna downlead are distributed in the various elements composing the X-Y mount, an OMT type junction included in the upper box enabling separation of the components of the downlead into two separate paths, a first path called the ascending path comprising components for amplifying and processing signals to be transmitted by the antenna, a second path called the descending path comprising components for processing and amplifying signals received by the antenna, the components associated with these paths being placed on either side of the various elements of the X-Y mount.

Abstract: The invention relates to a method of estimating symbols carried by a digital signal that is received by a receiver over a communication channel (5), said symbols being multiplexed or orthogonal frequency sub-carriers. The inventive method comprises the following steps in relation to each symbol carried by the digital signal, consisting in: performing at least two transforms towards the frequency domain (8,9) on a portion of the received signal essentially corresponding to the symbol, said transforms being performed with a determined time lag (10) therebetween: estimating the parameters (r0, r1, . . . , rn, r?0, r?1, . . . , r?n) of the communication channel from pre-determined binary information contained in the digital signal; and estimating the symbol from a combination of the result of each of the transforms performed and the estimated communication channel parameters.

Abstract: The present invention relates to a method for establishing a secured communication session in a communication system between a user using an untrusted device and a server. According to the present invention the user first obtains an authentication algorithm and an encryption algorithm and then creates a session key. Next the user obtains a public key of the server and sends a personal identity number to the server for authentication by using the authentication algorithm, the personal identity number being encrypted by using the encryption algorithm and the public key of the server. The user also sends the session key to the server for encrypting purpose between the user and the server, the session key being encrypted by using the encryption algorithm and the public key of the server.

Abstract: A method for configuring a node, said node holding a public key depending on an identifier relating to said node, a related secret key and an address of a configuration server storing sets of configuration parameters for respective nodes, the method comprising the following steps carried out at the configuration server: identifying said node by use of an identity based identification algorithm taking account of said public and secret keys; and when said node has been successfully identified, retrieving the set of configuration parameters stored for said node and transmitting said set of configuration parameters to said node.

Abstract: A system is provided for communications between at least two telecommunications devices, at least one being onboard an aircraft, said devices comprising means for sending and/or receiving digital data, said data being classed in at least two categories, the first category corresponding to critical data, the second category corresponding to non-critical data. The data are sent on M antennas and received on N antennas. A matrix H of dimension M×N representative of the multi-antenna propagation channel is estimated and the data are sent according to a mode of transmission selected from among at least two multi-antenna modes. A first robust mode uses a scheme of Alamouti type, a second high-speed mode uses a scheme of BLAST type. The critical data are transmitted using the robust mode, the non-critical data being transmitted using one of the two multi-antenna modes. The high-speed mode is selected when the rank RH of the matrix H exceeds a previously chosen threshold value SR.

Abstract: A method for configuring a node using a configuration server, as well as the node and the configuration server, are disclosed. The node holds a public key, a related secret key and an address of a configuration server. The node transmits the public and secret keys to the configuration server, which identifies the node by use of an identity based identification algorithm taking account of the public and secret keys. When the node has been successfully identified, the configuration server retrieves a set of configuration parameters stored for the node and transmits this set to the node. Accordingly, the node does not have to store much information. The use of identity-based identification algorithms to identify the node is advantageous regarding nodes that may have very low power/memory which might prevent them from embedding a heavy X.509 certificate traditionally used for identification or authentication purposes.

Abstract: To evaluate an energy level of a signal received through a radio interface between radiocommunication stations, successive measurement samples depending on the energy of the signal are obtained, and an average of said samples is calculated, to evaluate the energy level. The calculation of the average of the samples is performed with an averaging duration depending on a service to which the received signal pertains.

Abstract: In a system comprising a broadcasting subsystem and a radiocommunication subsystem each connected to a mediation platform, said transmission being ciphered and arranged for being deciphered by using a key, the following steps are performed at the mediation platform, relatively to a user or group of users having terminals: determining one first and at least one second sets of values from said key, so that the knowledge of all the determined sets of values is required to retrieve the key; and controlling the broadcasting subsystem so that it transmits the first set of values to the user or group of users and the radiocommunication subsystem so that it transmits the at least one second set of values to the user or group of users.

Abstract: Parameters for the propagation channels between each mobile terminal (14, 14A, 14B) and several fixed transceivers (13) are measured and a report message transmitted to a radio network controller (12), indicating at least one part of the measured parameters. The radio network controller processes the report messages. The parameters measured for each fixed transceiver are a propagation profile, including at least one propagation path associated with a reception energy and the parameters given in the report messages for at least one transceiver, comprise data on the energetic distribution in the propagation profile, taken into account by the radio network controller in processing.

Abstract: The invention relates to a method of estimating symbols carried by a digital signal that is received by a receiver over a communication channel (5), said symbols being multiplexed or orthogonal frequency sub-carriers. The inventive method comprises the following steps in relation to each symbol carried by the digital signal, consisting in: performing at least two transforms towards the frequency domain (8,9) on a portion of the received signal essentially corresponding to the symbol, said transforms being performed with a determined time lag (10) therebetween: estimating the parameters (r0, r1, . . . , rn, r?0, r?1, . . . , r?n) of the communication channel from pre-determined binary information contained in the digital signal; and estimating the symbol from a combination of the result of each of the transforms performed and the estimated communication channel parameters.

Abstract: The invention relates to transmission from a base station to a receiver, the base station comprising first radiating means arranged for transmitting according to an antenna pattern with respect to the receiver and further comprising second radiating means arranged for transmitting according to the same antenna pattern as the first radiating means with respect to the receiver, the transmissions of the first and second radiating means being time shifted by a determined duration.

Abstract: In a system comprising a broadcasting subsystem and a radiocommunication subsystem each connected to a mediation platform, said transmission being ciphered and arranged for being deciphered by using a key, the following steps are performed at the mediation platform, relatively to a user or group of users having terminals: determining one first and at least one second sets of values from said key, so that the knowledge of all the determined sets of values is required to retrieve the key; and controlling the broadcasting subsystem so that it transmits the first set of values to the user or group of users and the radiocommunication subsystem so that it transmits the at least one second set of values to the user or group of users.

Abstract: The invention relates to a method of estimating symbols carried by a digital signal that is received by a receiver over a communication channel (5), said symbols being multiplexed on orthogonal frequency sub-carriers. The inventive method comprises the following steps in relation to each symbol carried by the digital signal, consisting in: performing at least two transforms towards the frequency domain (8,9) on a portion of the received signal essentially corresponding to the symbol, said transforms being performed with a determined time lag (10) therebetween; estimating the parameters (r0, r1, . . . , rn, r?0, r?1, . . . , r?n) of the communication channel from pre-determined binary information contained in the digital signal; and estimating the symbol from a combination of the result of each of the transforms performed and the estimated communication channel parameters.

Abstract: The invention relates to transmission from a base station to a receiver, the base station comprising first radiating means arranged for transmitting according to an antenna pattern with respect to the receiver and further comprising second radiating means arranged for transmitting according to the same antenna pattern as the first radiating means with respect to the receiver, the transmissions of the first and second radiating means being time shifted by a determined duration.

Abstract: Parameters for the propagation channels between each mobile terminal (14, 14A, 14B) and several fixed transceivers (13) are measured and a report message transmitted to a radio network controller (12), indicating at least one part of the measured parameters. The ratio network controller processes the report messages. The parameters measured for each fixed transceiver are a propagation profile, including at least one propagation path associated with a reception energy and the parameters given in the report messages for at least one transceiver, comprise data on the energetic distribution in the propagation profile, taken into account by the radio network controller in processing.

Abstract: To perform security control for data flows exchanged between a communication module and a communication network in communication sessions organized in accordance with communication session contexts, a communication session is established with a remote unit, a corresponding communication session context is activated, and the data flows exchanged in accordance with the activated communication session context are controlled, within the established session, with respect to at least one parameter related to said context.

Abstract: A position-finding method in a radiocommunication system comprising at least one first and one second sub-system and means (34, 35, 36, 39) for finding the position of a mobile terminal (30), wherein the mobile system can communicate and carry out measurements relating to position-finding on each of the first and second sub-systems, and the position finding means for locating the mobile terminal are embodied in such a way that they can take into account certain measurements carried out by the mobile terminal. The inventive method comprises the following steps when the mobile terminal is connected to the first sub-system: measurements relating to position finding on the second sub-system are carried out in the mobile terminal; the measurements thus carried out are transmitted to the first sub-system; and carrying out the measurements in order to find the position of the mobile terminal by taking into account certain measurements, at least those transmitted to the first sub-system.