Abstract: A method and apparatus are provided for locating the positions of sensors of a network of sensors suitable for communicating with one another by radio connection. The method is suitable for receiving, from sensors of the network of sensors, measurements of relative distances between sensors of the network; for calculating a topology for the network of sensors from the received distance measurements, the topology comprising nodes representative of sensors of the network of sensors; and for determining absolute positions for the sensors by anchoring the calculated topology in an absolute frame of reference on the basis of constraints associated with an environment plan of the network of sensors. The invention also provides a locating device implementing the management method.

Abstract: A method and apparatus are provided for sending pulses from a sender device to a receiver device in a transmission channel. The pulses represent information symbols, with each of these pulses being associated with a time slot in a symbol time. The method includes a training step that is carried out before sending payload information and that includes sending a training sequence made up of two parts. A first part of the training sequence includes at least one pulse of energy that is greater than the energy of a pulse carrying payload information. There are a large number of time slots between the sending of the pulse and the sending of the next pulse. A second part of the training sequence includes a set of pulses known in advance and similar to the pulses used for carrying payload information, the energy of each of these pulses being equivalent to the energy of a pulse carrying payload information.

Abstract: A method is provided for encoding an image signal that includes motion information, by selecting a motion vector from among a set of at least three candidate vectors for at least one actual block of an actual image to be encoded. The method includes: determining an optimal-selection subset containing some of the candidate vectors; selecting the motion vector from among the vectors of the optimal-selection subset; and inserting into the signal a piece of information designating the motion vector selected from among the vectors of the optimal-selection subset.

Abstract: A method of assisting with the construction of a tree of clusters of electronic documents, the documents being defined by predetermined attributes. The method includes, for a given cluster of documents and a given level of the tree, the following steps: a) obtaining (E300) constraints defined between at least two documents of said cluster and storing those constraints; b) constructing (E310) subclusters as a function of the constraints obtained and the attributes of the documents of said cluster; c) creating (E320) a tree level corresponding to the subclusters created; and d) selecting (E340) a created subcluster and iterating the steps a), b), c) and d) for the selected subcluster until said tree is obtained. A device for implementing the method is also disclosed.

Abstract: A method is provided for handing off flows. The flow, having a flow identifier, is established between a terminal and a correspondent. The terminal has as many terminal identifiers as access interfaces to access networks of mutually different data technologies. A first execution entity converts a handoff execution order emanating from a decision entity into execution messages by taking into account a hierarchy of execution entities of a current network. After a handoff decision has been taken for a given pair of flow and terminal identifiers, the decision entity sends an execution order to the first execution entity. The first execution entity: selects a mobility protocol from the mobility protocols supported by the execution entities of the hierarchy associated with the current network; selects in the hierarchy at least one execution entity responsible for executing the mobility protocol; and sends to the selected execution entities respective execution messages.

Abstract: A method and device are provided for the objective evaluation of voice quality of a speech signal. The device includes: a module for extracting a background noise signal, referred to as a noise signal, from the speech signal; a module for calculating the audio parameters of the noise signal; a module for classifying the background noise contained in the noise signal on the basis of the calculated audio parameters, according to a predefined set of background noise classes; and a module for evaluating the voice quality of the speech signal on the basis of at least the resulting classification relative to the background noise in the speech signal.

Abstract: A method is provided of obtaining information representative of an availability of a communications network, which includes a plurality of equipment exchanging routing data in accordance with a routing protocol. The method includes a stage of storing in chronological order at least some of the routing data exchanged between at least one first equipment and at least one second equipment; a stage of totaling unavailability times as a function of the routing data stored in chronological order for a predetermined time period; a stage of obtaining the information representative of an availability for the time period as a function of the totaled unavailability times.

Abstract: A method of regulating traffic in a telecommunications network, including a first step of detecting a fault affecting a node or a link of the network. The second step below is then executed: the nodes located immediately upstream of said node/link that experienced the fault forward to the latter the registration requests sent by users of the network, to the extent that the throughput of said registration requests is below a predetermined clipping threshold associated with the registration requests; if the throughput of registration requests exceeds said clipping threshold, the excess requests are not forwarded to the node/link that experienced the fault, and the network sends to each user that sent a request refused in this way, a response prompting that user to observe a time-out period, said response specifying the recommended duration of said time-out period. Application in particular to IP networks using SIP signaling protocols.

Abstract: A method and device are provided for selecting a transmission mode, for a first telecommunications entity having a plurality of different modes for transmitting a communications signal to a second telecommunications entity. The various transmission modes provide the same data rate D. The method includes: for a given transmission mode, determining the value of a first metric ? that measures degradation relating to a given distance d stemming from the transmission medium of the communications signal for a given environment compared with a reference model for the transmission medium, as a result of a multi-path effect and/or of an attenuation effect of the transmission medium; and comparing values of the metric ? for different modes in order to select at least one transmission mode.

Abstract: A method of pre-equalizing a data signal transmitted in frequency division duplex includes receiving via an originating reference antenna a first pilot sequence transmitted by a destination antenna through a first channel, and estimating a first impulse response of the first channel; receiving via a destination antenna a second pilot sequence transmitted by an originating antenna through a second channel, and estimating a second impulse response of the second channel; receiving, via the reference antenna, a third pilot sequence modulated by the second impulse response and transmitted by the destination antenna, and estimating a combined impulse response of the first and second channels in succession; time reversing the combined impulse response; combining the time-reversed combined impulse response and the first impulse response; re-iterating the steps for a portion of the destination and originating antennas; and determining pre-equalization coefficients for the data signal from a set of the impulse response

Abstract: A method and apparatus are provided for coding a sequence of images. The method includes a step of coding at least one block of a current image of the sequence, implementing a prediction associating the block with at least one corresponding block in a reference image. The prediction includes the following steps, for at least one given block of the current image or of the reference image: determination of a plurality of control vectors for the block; at least one splitting of the block into sub-blocks; determination of a plurality of control vectors for the sub-blocks; and determination of a prediction value for at least one point of the current image. Moreover, the method includes a step of inserting, into a signal representative of the sequence, information regarding reconstruction of the control vectors for the given block.

Abstract: A method and apparatus are provided for determining a descriptor for a region of interest in an image. The method includes defining a grid of points for the region of interest. A respective zone of influence is associated with each point of the grid of points. A representative value is determined for each point of the grid of points as a function of its respective zone of influence. The representative value obtained for each point of the grid of points is compared with at least one reference value. The result of the comparison serves to define a descriptor for the region of interest.

Abstract: A method is provided for sending a communications signal in a communications network having a plurality of nodes assuming alternating sleeping and waking states and in which a sender node executes a step of sending an initial preamble, prior to sending data to a destination node. The method includes at least one operation of a neighbor node of the sender node relaying the initial preamble, where a relaying operation corresponds to sending a preamble formed from the preamble sent during the preceding relaying operation, the preamble sent during the first relaying operation being formed from the initial preamble, and the at least one relaying operation continuing until the destination node for the data detects the sent preamble.

Abstract: A method and apparatus are provided for coding an image or a sequence of images, generating a data stream including data representative of pixel groups, referred to as blocks, in one of the images. The method includes: grouping blocks in a cluster of blocks according to the proximity of their respective values corresponding to at least one block parameter to be coded; determining a value of the parameter, the value being characteristic of said group of blocks; coding blocks of the cluster, where the values of the blocks for the parameter are coded implicitly by inheritance of the characteristic value or are coded as refinements relative to the characteristic value, and coding a data structure associated with the cluster of blocks, the data structure including data associated with the characteristic value.

Abstract: A method and apparatus are provided for coding an image or a sequence of images, generating a data stream including data representative of pixel groups, referred to as blocks, in one of the images. The method includes: grouping blocks in a cluster of blocks according to the proximity of their respective values corresponding to at least one block parameter to be coded; determining a value of the parameter, the value being characteristic of said group of blocks; coding blocks of the cluster, where the values of the blocks for the parameter are coded implicitly by inheritance of the characteristic value or are coded as refinements relative to the characteristic value, and coding a data structure associated with the cluster of blocks, the data structure including data associated with the characteristic value.

Abstract: Telecommunications system including a network selection manager and a mobile node. The network selection manager is operable to determine a list of preferred mobile access networks to which the mobile node may be attached during an inactive state and to communicate the list of preferred mobile access networks to the mobile node. The list of preferred mobile access networks for selection is determined in accordance with operator determined conditions (e.g. load, congestion in the access networks, subscription info, location of the mobile, changes in the list since last communication to the Mobile Station, etc.). The mobile node is operable in the inactive state to select one of the plurality of mobile access networks which is available for attachment in dependence on the list of preferred mobile access networks communicated to the mobile node from the network selection manager.

Abstract: The present invention relates in a general manner to the generation of unavailability messages (MESS.TXT, MESS.VOC) upon a failure to establish a communication. Thus, in a method of communication comprising, on the sending of a call from a calling user (B) to a called user (A), there are provided the following steps: determining (E406), in an address book (100) of the called user, a group of contacts (110) comprising a contact corresponding to the calling user; determining the availability of the called user for the calling user as a function of an availability cue (142) associated, in the address book, with said determined group; in the event of determined unavailability of the called user, generating (E410, E320), for the attention of the calling user, a personalized unavailability message (MESS.TXT, MESS.VOC) on the basis of at least one information cue supplied (130, 142, 144, 146), in the address book, at the level of the group determined.

Abstract: A method is provided for supervising a plurality of units in a communications network. The method includes a step of a first supervisor device receiving from a plurality of units information notifications having a plurality of information fields. For each information notification received, at least one imprint is generated, which includes codes extracted from predetermined fields of the notification. The method further includes counting the number of occurrences of at least one imprint, and notifying at least one master supervisor device of at least one imprint and the number of occurrences counted for that imprint.

Abstract: A method of filtering packets coming from a communication network (1) comprising, after successful registration of a terminal (20) with a service platform (32): a step of associating a registration context with the terminal, the context comprising registration information transmitted between the terminal and the service platform during registration; a step of creating at least one filtering rule on the basis of the registration context, said rule aiming to block packets that do not conform to at least a portion of the registration information; and a step of filtering the packets as a function of the rule created.

Abstract: A method of pre-authentication of a first entity (10) by a second entity (1) communicating with each other via a wireless connection. The second entity (1) sends (23?) a challenge value (c). If the first entity (10) receives (23) a challenge value (c?), it applies to the received challenge value a predefined transformation (g) known to the second entity to obtain a first transformed value (r) and then sends (24) the first transformed value (r) obtained. If the second entity receives (24?) a transformed value (r?), it compares (25?) the received transformed value to a second transformed value (r?) obtained by applying the predefined transformation (g) to the challenge value sent and considers the pre-authentication to have succeeded if the result of comparing the second transformed value obtained and the transformed value received is below a predefined threshold (m).