Multiple access method and system with frequency multiplexing of several request to send messages per source node

The invention relates to a multiple access method to a frequency band of a communication channel of a communication network with carrier sensing and collision avoidance, said frequency band being broken down into a set of sub-bands (SB0, SB1, . . . , SBi, . . . , SBn) of the communication channel, characterized in that it comprises at a source node, after it has been detected that the communication channel is available, the transmission to a destination node of several request to send messages on the communication channel (RTS NS0, RTS NS1), each of said messages being sent on a sub-band of the communication channel.

Method of transmitting a communications signal

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.

METHOD OF TRANSMITTING A COMMUNICATIONS SIGNAL

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.

MULTIPLE ACCESS METHOD AND SYSTEM WITH FREQUENCY MULTIPLEXING OF SEVERAL REQUEST TO SEND MESSAGES PER SOURCE NODE

The invention relates to a multiple access method to a frequency band of a communication channel of a communication network with carrier sensing and collision avoidance, said frequency band being broken down into a set of sub-bands (SB0, SB1, . . . , SBi, . . . , SBn) of the communication channel, characterised in that it comprises at a source node, after it has been detected that the communication channel is available, the transmission to a destination node of several request to send messages on the communication channel (RTS NS0, RTS NS1), each of said messages being sent on a sub-band of the communication channel. 115-. (canceled)16. A multiple access method to a frequency band of a communication channel of a communication network with carrier sensing and collision avoidance , said frequency band being broken down into a set of sub-bands of the communication channel , the method comprising at a destination node , after it has been detected that the communication channel is available , a step of transmitting to a destination node several request to send on the communication channel messages , each of said messages being sent on a sub-band of the communication channel.17. The method according to claim 16 , in which the number of request to send on the communication channel messages transmitted by the source node depends on a level of priority associated with the source node.18. The method according claim 16 , comprising a selection by the source node of the sub-bands on which the request to send on the communication channel messages are to be sent.19. The method according to claim 16 , in which the set of sub-bands includes several groups of sub-bands claim 16 , and in which the source node is associated with a group of sub-bands and performs the transmission of each request to send on the communication channel message on one sub-band of the group of associated sub-bands.20. The method according to claim 16 , comprising an evaluation of a communication channel load ...

METHOD AND SYSTEM FOR MULTIPLE ACCESS WITH FREQUENTIAL MULTIPLEXING OF MULTIPLE SOURCE NODE DATA SENDING AUTHORIZATION REQUESTS

METHOD AND SYSTEM FOR MULTIPLE ACCESS WITH FREQUENTIAL MULTIPLEXING OF MULTIPLE SOURCE NODE DATA SENDING AUTHORIZATION REQUEST

L'invention concerne un procédé d'accès multiple à une bande de fréquence d'un canal de communication d'un réseau de communication avec écoute de porteuse et évitement de collision, ladite bande de fréquence étant découpée en un ensemble de sous-bandes (SBO, SB1, SBi, SBn) du canal de communication, caractérisé en ce qu'il comprend à un nœud source, suite à la détection de la disponibilité du canal de communication, la transmission à un nœud destinataire de plusieurs messages de requête d'autorisation d'envoi de données sur le canal de communication (RTS NSO, RTS NS1), chacun desdits messages étant transmis sur une sous-bande du canal de communication. The invention relates to a method for multiple access to a frequency band of a communication channel of a communication network with carrier listening and collision avoidance, said frequency band being divided into a set of sub-bands ( SBO, SB1, SBi, SBn) of the communication channel, characterized in that it comprises at a source node, following the detection of the availability of the communication channel, the transmission to a destination node of several request messages of authorization to send data over the communication channel (RTS NSO, RTS NS1), each of said messages being transmitted on a sub-band of the communication channel.

Communication signal transmission method

The invention relates to a method for transmitting a communication signal in a communication network including a plurality of nodes alternately corresponding to sleep periods and wake periods, a transmitting node ensuring that the transmission of data to a destination node is preceded by a step comprising the transmission of an initial preamble. According to the invention, the method includes at least one initial preamble transmission relay through a node adjacent to the transmitting node, whereby a relay corresponds to the transmission of a preamble formed from the preamble transmitted during the previous relay, the preamble transmitted at the time of the first relay is formed from the initial preamble and said at least one relay is ensured until the data destination node detects the transmitted preamble.

Ultrasound contrast imaging with multiple-pulse excitation waveforms

The method of imaging the nonlinear components of ultrasound echo signals returned from scatterers comprises the steps of constructing a multi-pulse excitation waveform, the pulses composing this waveform having spectra with known relative frequency dependencies, differing in amplitude and phase so that the multi-pulse waveform can be considered as a convolution of any single of said pulses with a known coding function, transmitting said multiple-pulse waveform within a single transmission of an ultrasound beam in the direction of said scatterers, decoding the received rf-waveform by a first appropriate decoding function to obtain a new rf-waveform, decoding said received rf-waveform by a second and different appropriate decoding function to obtain another rf-waveform realigning in time, as required, both decoded rf-waveforms obtained from the same returned echo signal by a time delay as determined by the transmit-coding function, normalizing amplitudes and combining both rf-waveforms to enhance echo components caused by nonlinear scatterers and essentially suppress echo components caused by linear scatterers.

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