• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
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    • 专利摘要:
    The invention relates to a method of multiple access to a frequency band of a communication channel of a communication network with carrier listening and collision avoidance, comprising a division of the frequency band into a set of sub-links. transmission request bands (SB0, SB1, SBi, SBn) dedicated to the transmission, by source nodes to a destination node, of messages (RST NS0, RTS NS1) requesting authorization to send data on the frequency band, characterized in that it comprises: - an evaluation of a load of the communication channel, and - according to the result of said evaluation, a redrawing of the frequency band to modify the number of sub-bands of said set of send request subbands.
    公开号:FR3039031A1
    申请号:FR1556794
    申请日:2015-07-17
    公开日:2017-01-20
    发明作者:Baher Mawlawi；Jean-Baptiste Dore
    申请人:Commissariat a lEnergie Atomique CEA；Commissariat a lEnergie Atomique et aux Energies Alternatives CEA；
    IPC主号:
    专利说明:

    METHOD AND SYSTEM FOR MULTIPLE ACCESS WITH ADAPTIVE FREQUENCY MULTIPLEXING OF DATA SENDING AUTHORIZATION REQUESTS
    DESCRIPTION
    TECHNICAL AREA
    The field of the invention is that of multiple access to a frequency band of a communication network with carrier listening and collision avoidance.
    STATE OF THE PRIOR ART Carrier listening and collision avoidance known by the acronym CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) is a multiple access protocol that can be used in communication systems. radiocommunications to manage the allocation of the radio resource.
    This protocol is used to avoid collisions between multiple users (source nodes) wishing to access a common access point (destination node) on the uplink at the same time.
    In an implementation of this protocol, a source node wishing to transmit data listens to the communication channel. If the channel is busy, a duration (expressed in number of time slots) of a wait counter (known as the "backoff counter") is randomly selected in a range [0, CW-1], where CW represents a contention window. The wait counter is decremented by 1 each time the channel is detected to be available over a DIFS ("Distributed Inter-Frame Space") time. The standby counter is stopped when the channel is busy, and resumes when the channel is available again for at least DIFS time.
    When the wait counter reaches zero, the source node transmits a Request To Send (RTS) request request message to the destination node, and waits to receive an authorization message for sending the request. CTS ("Clear To Send") data of the destination node before transmitting the data. On receipt of all the transmitted data, and immediately after expiration of a SIFS ("Short Inter-Frame Space"), the destination node sends an acknowledgment message ACK (for "ACKnowledgment").
    The contention window CW is an integer within an interval [CWmin, CWmax]. This window CW is initially set to the minimum value CWmin. Each time a source node is involved in a collision, it increases its waiting time by doubling the CW window, up to the maximum value CWmax. On the other hand, if a transmission succeeds, the source node reduces the window CW to its minimum value CWmin.
    A CSMA / CA system in conventional single-channel operation has the advantage of requiring neither signaling for the bandwidth request nor allocation according to a planned access. On the other hand, its efficiency is rather weak insofar as its performances deteriorate rapidly when the number of source nodes increases.
    This limitation can be overcome by using a multiple divisional access on different sub-bands according to which several source nodes can transmit simultaneously on different sub-bands, the source nodes knowing the state of availability of each of the sub-bands at each moment. This multiple divisional access on different sub-bands exploits for example the OFDMA (Orthogonal Frequency Division Multiple Access) access method according to which the spectral resource (frequency band) is divided into a set of orthogonal subcarriers. This set of sub-carriers is itself divided into subsets, each subset of sub-carriers constituting a sub-band. The source nodes thus compete for access to the resource both in time and in frequency.
    It has thus been proposed to divide a frequency band of a communication channel into a set of send request subbands dedicated to the transmission, by source nodes to a destination node, of request RTS messages from authorization to send data on the frequency band. The receiving node listens independently to each of the subbands, and if it detects one or more RTS messages, it sends a CTS authorization message to send data to a selected source node, randomly or not, among the node (s). sources that have transmitted the RTS message (s) detected by the destination node. The selected source node transmits its data and waits to receive the acknowledgment message ACK. The CTS message, the data and the ACK message are transmitted over the entire communication channel, namely on all the sub-bands.
    For example, reference can be made to patent application EP 2 822 231 A1, which proposes that each source node comes to transmit an RTS message on one or more of the send request sub-bands forming a subset of said set of sub-sets. sending request tapes.
    Reference may also be made to patent application EP 2871 903 A1, which proposes that each source node comes to transmit several RTS messages, each on one of the sending request subbands, so as to increase the probability that an RTS message reaches the destination node and is correctly decoded. Indeed, a collision only occurs if each of the RTS messages transmitted by a source node is involved in a collision on the sending request subband on which it is transmitted. It is also expected that the number of RTS messages transmitted by a source node can be dynamically changed depending on the load of the communication channel, resulting in better overall performance.
    DISCLOSURE OF THE INVENTION The object of the invention is to provide a technique for improving the transmission capabilities of a CSMA / CA system operating multiple sending request subbands. To this end, it proposes a method of multiple access to a frequency band of a communication channel of a communication network with carrier listening and collision avoidance, in which the frequency band is divided into a set of subsets. -submission request bands dedicated to the transmission, by source nodes to a destination node, of authorization request messages for sending data on the frequency band, the method being characterized in that it comprises the following steps: - implementation of the multiple access to the frequency band divided into a first number of sub-bands during a first time window, and evaluation of the bit rate of the data sent on the frequency band during the first time window - modification of the division of the frequency band, implementation of the multiple access to the frequency band cut into a second number of sub-bands during a period second time window, and evaluation of the bit rate of the data sent on the frequency band during the second time window, - comparison of the bit rate of the data sent on the frequency band during the first time window at the bit rate of the data sent on the band of frequency during the second time window, - modification of the frequency band division of increasing or decreasing the number of sub-bands according to the result of the comparison of the bit rates.
    Some preferred but nonlimiting aspects of this method are as follows: if the bit rate during the first time window is greater than the bit rate during the second time window, the modification of the frequency band division consists of modifying the number of sub-bits. send request bands of the second number to said first number, and the method further comprises the steps of expanding the first time slot and implementing the multiple access to the frequency band cut into said first number of sub -Submission request bands during the first extended time window; it comprises at the end of the first extended time window: an evaluation of the bit rate of the data sent on the frequency band during the first enlarged time window; o a modification of the division of the frequency band, the implementation of the multiple access to the frequency band cut into said second number of sending request sub-bands during a new second time window, and an evaluation of the bit rate of the data sent on the frequency band during the second second time window; o a comparison of the bit rate during the first widened time window to the bit rate during the new second time window. if the bit rate during the first enlarged time window is greater than the bit rate during the new second time window, the frequency band is redrawn at said first number of send request subbands, and the method further comprises the steps expanding the first expanded time window again and implementing the multiple access to the frequency band cut into said first number of send request subbands during the first expanded time window; if the bit rate during the first time window is less than the bit rate during the second time window, the modification of the frequency band division consists of modifying the number of sending request subbands from the second number to a third number and the method further comprises performing multiple access to the frequency band cut into said third number of send request subbands during a third time slot; it comprises at the end of the third time window: an evaluation of the bit rate of the data sent on the frequency band during the third time window; o a comparison of the bit rate during the third time window at the bit rate during the second time window, if the bit rate during the second time window is greater than the bit rate during the third time window, the frequency band is redrawn into said second time slot; send request subbands, and the method further includes the steps of expanding the second time window and implementing the multiple access to the frequency band cut into said second number of request subbands during the second extended time window. The invention also relates to a destination node of a frequency band multiple access communication network of a carrier listening and collision avoidance communication channel, comprising: - a detection unit configured to detect messages simultaneous request for authorization to send data on the communication channel from a plurality of source nodes to a plurality of sub-bands resulting from the division of the frequency band into a set of request sub-bands of sending; a transmission unit configured to transmit an authorization message for sending data on the communication channel by at least one source node from among said plurality of source nodes (CTS NSO), said message comprising a field indicative of the number of subnets; -bands in said set of send request subbands.
    BRIEF DESCRIPTION OF THE DRAWINGS Other aspects, objects, advantages and characteristics of the invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made in reference to the accompanying drawings, in which: FIG. 1 is a diagram illustrating the variation of the number of source nodes over time, and the dynamic modification of the number of sub-bands of the sending request proposed by the invention; FIG. 2 is a diagram illustrating the data transiting on the different subbands in a possible embodiment of the invention; FIGS. 3 and 4 are schemas of state machines representative of algorithms that can be implemented in the context of the invention for modifying the number of sending request subbands.
    DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS In general, the invention is based on the observation that the number of sending request subbands, dedicated to the transmission of RTS messages by the source nodes, plays an important role. overall performance, particularly in terms of throughput.
    This observation is primarily based on the fact that it is not desirable for the number of send request sub-bands to be systematically low. Indeed, in a charged communication network, with for example many source nodes competing for access to the uplink, the collision probability increases and it is preferable to increase the number of request subbands of sending to reduce this probability. On the other hand, it is also not desirable that the number of send request subbands be systematically high. Indeed, the division of the frequency band into multiple send request subbands increases the time required to transmit an RTS message to the destination node, which degrades the performance.
    In this context, the invention proposes to dynamically adapt the number of sending request sub-bands as a function of the load of the communication channel. In this way, if the number of collisions increases, the number of sending request subbands is increased, and conversely, if the number of collisions decreases, the number of sending request subbands is reduced.
    FIG. 1 is a diagram illustrating this principle on which is represented the variation of the number S of source nodes (in full line, left scale) during the time t, and the dynamic modification of the number N of request sub-bands d sending (dashed line, left scale) proposed by the invention to take into account the number S of source nodes and adapt to the load of the communication channel. According to a first aspect, the invention relates to a method of multiple access to a frequency band of a communication channel of a communication network, for example a wireless network, with carrier listening and collision avoidance.
    With reference to FIG. 2, the frequency band is divided into a set of send request subbands SBO, SB1,..., SBi,..., SBn, said sending request subbands. being dedicated to the transmission, by source nodes NSO, NSI to a destination node, authorization request messages for sending data on the frequency band of the communication channel "RTS NSO", "RTS NSI".
    Frequency multiplexing for the transmission of RTS messages is thus allowed, several source nodes being able to simultaneously transmit such RTS messages on different sending request subbands. This frequency multiplexing exploits, for example, the OFDMA (Orthogonal Frequency Division Multiple Access) access method in which the spectral resource (frequency band) is divided into a set of orthogonal subcarriers. This set of sub-carriers is itself divided into subsets, each subset of sub-carriers constituting a sub-band. This frequency multiplexing can also exploit other types of multi-carrier modulation, such as for example a multi-carrier system based filter banks based FBMC ("Filter Bank based Multi-Carrier").
    In the context of the invention, each source node has a wait counter whose value is modified (typically decremented by 1) when the communication channel in its entirety is detected as being available for a given duration (duration DIFS under the CSMA / CA protocol). The communication channel is available when no transmission takes place on all the subbands SBO, SBI, ..., SBi, ..., SBn of the communication channel.
    When the standby counter of a source node reaches a predetermined value (typically zero), the source node transmits its data after implementation of a modified RTS / CTS mechanism.
    According to this modified RTS / CTS mechanism, the method comprises the transmission by a source node, following the detection of the availability of the communication channel, of one or more authorization request messages for sending data on the data band. frequency, each of said messages being transmitted on one or more send request subbands forming a subset of said set of send request subbands.
    This mechanism may be that described in the application EP 2 822 231 A1 according to which the source node transmits an authorization request message for sending data on the communication channel (RTS type message) on one or more sub-bands. forming a subset of said set of sub-bands of the communication channel (in other words, the message is not transmitted on all subbands).
    It may also be the mechanism described in the application EP 2 871 903 A1 according to which the source node transmits a plurality of data transfer authorization request messages on the communication channel, each of said messages being transmitted over the transmission channel. one of the send request subbands. In this context, the number of RTS messages transmitted by a source node is advantageously dynamically modified as a function of the load of the communication channel.
    An example of this second mechanism is illustrated in FIG. 2. In this example, following the detection of the availability of the communication channel, the source node NSO transmits a plurality (N = 2) of "RTS NSO" messages, namely a message on the SBO sub-band and a message on the sub-band SBi, and the source node NSI also transmits a plurality (N = 2) of "RTS NSI" messages, namely a message on the SBI sub-band and a message on the SBn sub-band.
    This number N of RTS type messages that a source node can transmit each on one of the sending request subbands can advantageously be modified over time. In this way, the invention extends not only to the case where a source node always transmits several RTS type messages whose quantity can be modified, but also to the case where under certain conditions the source node only transmits a single message type RTS and where under other conditions the source node transmits a plurality of RTS type messages.
    In this second mechanism, the authorization request to send data on the communication channel sent by a source node can be incorrectly received by the destination node only if all the N corresponding messages have collided with other messages. .
    FIG. 2 represents in this respect an example of a collision in a sub-band which does not affect the correct reception by the destination node of a request for authorization to send data on the communication channel sent by a source node . In this example, the "RTS NSO" and "RTS NSI" messages collide on the SBi sub-band. However, because of the diversity offered by the transmission of several RTS-type messages on several sub-bands, no collision is observed on the Sbn sub-band, nor is there any collision on the SBO sub-band. The "RTS NSO" and "RTS NSI" messages, respectively transmitted on the SBO sub-band and on the SBn sub-band, are therefore correctly received by the destination node.
    In one embodiment, subbands for transmission by a source node of the RTS messages are imposed, for example via a list of subbands which the source node can view.
    In another embodiment, the source node selects the sub-band (s) for transmitting the RTS message (s). The selection can take place according to a distribution probability law on each of the sub-bands or on each of the sub-bands of a subset of the set of subbands imposed on the source node. The law of probability is for example a random law. It can, however, take a more elaborate form.
    In one embodiment, the number of RTS messages transmitted by a source node is a function of a priority level associated with the source node. Thus a source node of higher priority than another source node then transmits more RTS messages than said other node. It is understood that the source node of high priority then has higher chances of a correct reception of at least one of its RTS type messages and therefore a more likely access to the communication channel.
    The destination node includes a detection unit configured to detect RTS messages simultaneously transmitted by a plurality of source nodes to a plurality of non-colliding and sending request subbands (in FIG. simultaneous messages "RTS NSO" and "RTS NSI" respectively transmitted on the subbands SBO and SBn).
    The destination node further comprises a transmission unit configured to transmit a CTS type message for authorization to send data on the communication channel by at least one source node from among said plurality of source nodes "CTS NSO". The source node or nodes authorized to transmit on the communication channel then proceed to send their data "DATA NSO" on the communication channel, that is to say on all the sub-bands of the communication channel. Once a data transmission is completed, and if successful, the destination node sends an acknowledgment message ACK.
    The CTS type message for authorization to send data on the communication channel by at least one source node from among said plurality of source nodes "CTS NSO" is also transmitted on the communication channel, on all the sub-bands.
    According to the invention, the destination node's detection unit is configured to listen to each of the sub-bands and to detect simultaneous requests for permission to send data from a plurality of source nodes. Simultaneous messages are messages sent by source nodes in the same time slot when the source nodes and the destination node are synchronized, or messages sent by source nodes in the same time window starting with the availability of the channel. communication and taking into consideration the time necessary to maintain the availability before transmission (DIFS type) as well as the delay of propagation of the different source nodes.
    With reference to FIG. 2, the destination node can thus detect two simultaneous messages "RTS NSO", "RTS NSI" requesting authorization to send data on the communication channel coming from two source nodes NSO, NSI and not collided. In the context of a conventional CSMA / CA protocol, the two messages would have been simultaneously transmitted on the communication channel where they would have collided, so that neither of the two source nodes could have transmitted. In the context of the invention, the risk of collision is greatly reduced since the messages are each transmitted on a sub-band sending request. And this risk is of course the lower the number of sub-bands is important. Since the probability of collision of simultaneous RTS messages is reduced, the overall performance of the system is improved.
    In one embodiment, the destination node randomly selects one or more source nodes from among the plurality of source nodes that have simultaneously transmitted a request message for authorization to send data over the communication channel.
    In another embodiment, the destination node selects, based on a priority level associated with each source node, one or more source nodes among the plurality of source nodes that have simultaneously transmitted an authorization request message. sending data on the communication channel (for example by selecting the source node or nodes of highest priority, so as to ensure a certain level of quality of service).
    With reference to FIG. 2, only one NSO source node is selected (randomly or because of its priority level) and an authorization message for sending data on the communication channel by the selected source node "CTS NSO" is transmitted over the entire communication channel. After reception of the data sending authorization message "CTS NSO", the selected source node NSO transmits its data "DATA NSO" over the entire communication channel and then waits for an acknowledgment message "ACK" transmitted by the destination node also over the entire communication channel.
    According to another embodiment of the invention, sending the data of a set of source nodes that can include up to m source nodes is planned. In this case, the destination node can order up to m source nodes that will be able to transmit their data without having to retry the transmission with one or more new RTS messages. If the number n of properly decoded RTS messages at the destination node is smaller than the number m, then the n source nodes are selected. If, on the contrary, the number n of simultaneous RTS messages is greater than m, the destination node then selects m source nodes from n, either randomly or according to their priority level.
    The destination node transmits an authorization message for sending data on the communication channel by a set of source nodes (said set comprising all, when n <m, or part, when n> m, nodes of said plurality of nodes). source nodes) including an indication field, for each source node of said set, of a transmission on the immediate or deferred communication channel after listening of one or more reception acknowledgment messages transmitted by the destination node on the communication channel . For example, two source nodes NSO and NSI can be selected, and the authorization message for sending data on the communication channel by the selected source nodes "CTS NS0 & NS1" includes a field indicating immediate transmission the first NSO source node and a delayed transmission of the second NSI source node after listening to a data receiving ACK acknowledgment message transmitted by the destination node. Thus, after receiving the data sending authorization message "CTS NS0 & NS1", the source node NSO transmits its data "DATA NSO" over the entire communication channel and then waits for a reception acknowledgment message " ACK "transmitted by the destination node, for example over the entire communication channel. After listening to the acknowledgment message, the source node NSI transmits its data "DATA NSI" and waits for an acknowledgment message "ACK".
    The method according to the invention is characterized in that the division of the frequency band into a plurality of send request sub-bands is not fixed, but is instead dynamically modified as a function of the load of the transmission channel. communication.
    Thus, the number of send request subbands changes over time to increase when the load is high to reduce the probability of collision, and conversely to decrease when the load is low so as not to slow down unnecessarily. the transmission of RTS messages. The invention generally extends to multiple changes in the number of send request subbands, with at least one pass through a multi-subband strategy (number of subbands at least equal to 2) without excluding a passage by a strategy where the number of sub-bands is equal to 1.
    The method according to the invention thus comprises the evaluation of a load of the communication channel, and, depending on the result of said evaluation, a redrawing of the frequency band to modify the number of sub-bands of said set of sub-links. send request tapes. The evaluation of the load of the communication channel, and the decision of redrawing of the frequency band to modify the number of send request sub-bands, are more precisely carried out by means of a learning algorithm exploiting a estimation of the bit rate estimated by the destination node as a metric representative of the load of the communication channel.
    The bit rate can be estimated by the destination node as being the ratio between the time spent in data reception mode (corresponding to the receipt of the "DATA NSO" message in the example of FIG. 2) and a time interval considered. for multiple access to the frequency band.
    For starters, a number of send request subbands are set to a first number and multiple access is made with that number of send request subbands during a first time window. At the end of the first time window, the bit rate during the first time window is calculated, and the frequency band is redrawn to change the number of send request subbands from the first number to a second number. Frequency band multiple access is then implemented with said second number of send request subbands during a second time window, which is preferably of duration at most equal to that of the first time window. At the end of the second time window, the destination node determines the bit rate during the second time window, and the number of subbands is modified or not according to the result of a comparison of the bit rate during the first time window. with the bit rate during the second time window. The exact number of send request subbands for multiple access following the outcome of the second time window is broadcast to the source nodes through the CTS message.
    An example of a decision to change the number of send request subbands is as follows.
    If the bit rate during the time window is greater than the bit rate during the second time window, the frequency band is redrawn to modify the number of send request subbands of the second number to said first number, the first time slot is widened and the multiple access to the frequency band is implemented with said first number of bands during the first enlarged time window. In other words, we re-adopt the first division since it allows to ensure a better rate, and this for a longer period (the first time window is expanded) which offers in particular a more reliable estimate of the bit rate . On the other hand, if the bit rate during the first time window is less than the bit rate during the second time window, the frequency band is redrawn to modify the number of send request subbands of the second number to a third number, and the multiple access to the frequency band is implemented with said third number during a third time window. In other words, there is a new modification of the number of sub-bands because the second cutting provides a better flow than the first cutting and then we seek to find the best cutting.
    These steps are then repeated at the end of the third time window, by comparing the bit rate obtained with the third number of subbands to that obtained with the second number of subbands. If it is less good, we re-adopt the second number on a second extended time window. If it is better, the number of subbands is changed to a fourth number to implement the multiple access during a fourth time window. Note that by providing second, third and fourth time windows of duration at most equal to that of the first time window (before enlargement), the method makes it possible to be responsive to a possible change in the load of the communication channel.
    This algorithm is illustrated by the state machines shown in FIGS. 3 and 4. In FIG. 3, the initial number of sub-bands is set to a maximum number (3 in the example) and the number of sub-bands is modified. -bands from the first number to the second number and from the second number to the third number consists in reducing the number of subbands (decrement of one unit in the example). In FIG. 4, the initial number of sub-bands is set to a minimum number (1 in the example) and the modification of the number of bands from the first number to the second number and from the second number to the third number consists in increasing the number of subbands (increment of one unit in the example). In each of these figures, two time window widenings are possible to adopt one of three possible durations T1, T2 and T3 with T3> T2> T1. The invention is however not limited by this number of three, but extends to any number n of possible durations. In each of these figures, a circle represents the implementation of a multiple access exploiting a division into a number of subbands indicated by the number at the top in the circle over a period represented by T1, T2 or T3 at the bottom in The circle. Finally, in these figures, the starting and ending points correspond to the maximum and minimum numbers of subbands. But the invention is not limited to such a case, the starting and finishing points may correspond to any value between a minimum number and a maximum number of subbands.
    With reference to FIG. 3, the method starts with a four-band division operated during a first time window of duration T1. At the end of T1, the bit rate D4 is estimated. Then we operate a division into three bands during a second time window of duration T1 and evaluate the rate D3 then obtained.
    If the rate D4 is better than the bit rate D3, a four-band redistribution is carried out which is exploited during a first time window of extended duration T2 to observe a new bit rate D4. At the end of this extended duration T2, a three-band division is used during a second time window of duration T1 and the rate D3 is evaluated again. If the flow D4 remains better than the flow D3, a redrawing is carried out in four bands that is operated during a first time window again enlarged time T3, etc.
    If the bit rate D4 is less good than the bit rate D3, a two-band redistribution is carried out which is exploited during a third time window of duration T1. The bit rate D2 is evaluated. If D3 is better than D2, we return to exploit a division into three bands, this time on a second time window of extended duration T2. If D2 is better than D1, multi-band access is exploited during a fourth time window of duration T1 and then D1 is compared with D2 to decide whether or not to exploit a two-band division.
    With reference to FIG. 4, the method starts with a division into a band operated during a first time window of duration T1. At the end of T1, the rate D1 is estimated. Then we operate a split in two bands during a second time window of duration T1 and evaluate the rate D2 then obtained.
    If the rate D1 is better than the rate D2, a redrawing is carried out in a strip which is operated during a first extended time window of duration T2 to observe a new rate D1. At the end of this extended period of time, a two-band division is used during a second time slot T1 and the rate D2 is evaluated again. If the flow D1 remains better than the flow D2, a redrawing is carried out in a band which is operated during a first time window again enlarged duration T3, etc.
    If the flow D1 is less good than the flow D2, a redrawing is carried out in three bands that is operated during a third time window T1. The flow rate D3 is evaluated. If D2 is better than D3, we return to exploit a division into two bands, this time on a second extended time window of duration T2. If D3 is better than D2, a four-band multiple access is exploited during a fourth time window of duration T1 and then D3 is compared to D4 to decide whether or not to exploit a three-band division.
    The state machines of FIGS. 3 and 4 can be implemented together, that of FIG. 4 being implemented once that of FIG. 3 has led to consider the minimum number of sub-bands and that of FIG. implementation once that of Figure 4 led to consider the maximum number of subbands. The invention is not limited to the method as described above, but also extends to a destination node of a frequency band multiple access communication network of a communication channel with carrier listening and avoidance collision system, comprising: - a detection unit configured to detect simultaneous requests for authorization to send data on the communication channel from a plurality of source nodes to a plurality of sub-bands resulting from the division of the frequency band into a set of send request subbands; a transmission unit configured to transmit an authorization message for sending data on the communication channel by at least one source node from among said plurality of source nodes, said message comprising a field indicative of the number of sub-bands in said set of send request subbands.
    The CTS authorization message for sending data on the communication channel thus makes it possible to inform each of the source nodes as to the number of sub-bands of sending request for the transmission of the RTS type messages, this information being able to be completed by information relating to the selection of sub-bands (type of distribution probability law, limitation to a group of sub-bands, etc.) and the number of RTS messages to be transmitted.
    The destination node may further comprise an evaluation unit configured to estimate a load of the communication channel, and a redrawing unit configured to determine the number of send request subbands to result from a division of the band. frequency as a function of the load estimated by the evaluation unit. The invention also relates to a frequency band multiple access communication network of a carrier listening and collision avoidance communication channel, comprising source nodes and a destination node according to the invention.
    权利要求:
    Claims (12)
    [1" id="c-fr-0001]
    A method of multiple access to a frequency band of a communication channel of a carrier-aware communication network and collision avoidance, wherein the frequency band is divided into a set of request subbands of flight (SBO, SB1, -, SBi, SBn) dedicated to the transmission, by source nodes to a destination node, of messages (RST NSO, RTS NSI) requesting authorization to send data on the band frequency, the method being characterized in that it comprises the following steps: - implementation of the multiple access to the frequency band cut into a first number of sending request subbands during a first time window , and evaluation of the bit rate of the data sent on the frequency band during the first time window, - modification of the frequency band division, implementation of the multiple access to the frequency band divided into a second the number of sending request subbands during a second time window, and evaluating the bit rate of the data sent on the frequency band during the second time window, - comparing the bit rate of the data sent on the frequency band during the first time window at the bit rate of the data sent on the frequency band during the second time window, - modification of the frequency band division of increasing or decreasing the number of transmission request subbands as a function of the result of the comparison of bit rates.
    [2" id="c-fr-0002]
    The method of claim 1, wherein if the bit rate during the first time window is greater than the bit rate during the second time slot, the modification of the frequency band slicing is to change the number of request subbands. sending the second number to said first number, and further comprising the steps of expanding the first time window and implementing the multiple access to the frequency band cut into said first number of request subbands d sending during the first extended time window,
    [3" id="c-fr-0003]
    3. Method according to claim 2, comprising at the end of the first enlarged time window: an evaluation of the bit rate of the data sent on the frequency band during the first enlarged time window; a modification of the division of the frequency band, the implementation of I multiple access to the frequency band cut into said second number of sending request sub-bands during a new second time window, and an evaluation of the bit rate data sent on the frequency band during the new second time window; a comparison of the bit rate during the first widened time window at the bit rate during the new second time window.
    [4" id="c-fr-0004]
    4. The method according to claim 3, wherein if the bit rate during the first enlarged time window is greater than the bit rate during the new second time window, the frequency band is redrawn into said first number of request subbands. sending, and further comprising the steps of widening again the first enlarged time window and implementing the multiple access to the frequency band cut into said first number of send request subbands during the first time window again enlarged.
    [5" id="c-fr-0005]
    5. Method according to one of claims 1 to 4, wherein if the bit rate during the first time window is less than the bit rate during the second time window, the modification of the frequency band division consists in modifying the number of request subbands for sending the second number to a third number, and further comprising implementing multiple access to the frequency band cut into said third number of send request subbands during a third time window.
    [6" id="c-fr-0006]
    6. Method according to claim 5, comprising at the end of the third time window: an evaluation of the bit rate of the data sent on the frequency band during the third time window; a comparison of the bit rate during the third time window at the bit rate during the second time window.
    [7" id="c-fr-0007]
    The method of claim 6, wherein if the bit rate during the second time window is greater than the bit rate during the third time slot, the frequency band is redrawn into said second number of send request subbands, and further comprising the steps of expanding the second time window and performing multiple access to the frequency band cut into said second number of send request subbands during the second expanded time window.
    [8" id="c-fr-0008]
    8. Method according to one of claims 1 to 7, comprising at a source node: the detection of the availability of the communication channel; - following the detection of the availability of the communication channel, the modification of a value of a waiting counter; and when the value of the waiting counter reaches a predetermined value, the transmission to the destination node of one or more request messages for authorization to send data on the frequency band (RTS NSO, RTS NSI) each of said messages being transmitted on one or more send request subbands forming a subset of said set of eoyoi request subbands.
    [9" id="c-fr-0009]
    9. The method as claimed in claim 8, comprising transmitting to the destination node, by the source node, a plurality of data transmission request messages on the frequency band, each of said messages being transmitted on a request sub-band. shipment.
    [10" id="c-fr-0010]
    The method according to claim 9, further comprising, based on the result of the comparison, a modification of the number of authorization request messages sending data on the frequency band transmitted by the source node following detection of the availability of the communication channel.
    [11" id="c-fr-0011]
    11. Method according to one of claims 1 to 10, comprising the destination node: - the detection of simultaneous messages request for authorization to send data (PTS NSQ, RTS NSI) on the frequency band transmitted by a plurality source nodes on a plurality of send request subbands, - transmitting an authorization message for sending data on the frequency band by at least one of said plurality of source nodes {CTS NS0), said data sending authorization message comprising a field indicative of the number of sub-bands resulting from the division of the frequency band.
    [12" id="c-fr-0012]
    12, the destination node of a multi-access communication network with a frequency band of a communication channel with carrier listening and collision avoidance, comprising: - a detection unit configured to detect simultaneous authorization request messages sending data over the communication channel (RTS NSO, RTS NSI) from a plurality of source nodes to a plurality of sub-bands resulting from the division of the frequency band into a set of request subbands d sending; a transmission unit configured to transmit an authorization message for sending data on the communication channel by at least one source node of said plurality of source nodes (CTS NSO), said message comprising a field indicative of the number of subscribers; tapes in said set of send request subbands.
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    同族专利:
    公开号 | 公开日
    EP3119155A1|2017-01-18|
    US10158459B2|2018-12-18|
    EP3119155B1|2018-11-07|
    US20170019223A1|2017-01-19|
    FR3039031B1|2017-07-21|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR3008266A1|2013-07-03|2015-01-09|Commissariat Energie Atomique|METHOD AND SYSTEM FOR MULTIPLE ACCESS WITH FREQUENTIAL MULTIPLEXING OF DATA SENDER AUTHORIZATION REQUESTS|
    FR3012931A1|2013-11-06|2015-05-08|Commissariat Energie Atomique|METHOD AND SYSTEM FOR MULTIPLE ACCESS WITH FREQUENTIAL MULTIPLEXING OF MULTIPLE SOURCE NODE DATA SENDING AUTHORIZATION REQUEST|
    US7808908B1|2006-09-20|2010-10-05|Meru Networks|Wireless rate adaptation|
    US8134958B2|2007-10-08|2012-03-13|Nec Laboratories America, Inc.|Synchronous two-phase rate and power control in WLANs|FR3050345B1|2016-04-13|2018-04-13|Commissariat A L'energie Atomique Et Aux Energies Alternatives|RECEIVER FOR FBMC SYSTEM WITH BLOCKED ALUMINUM TYPE SPATIO-TEMPORAL ENCODING|
    CN109257075B|2017-07-12|2021-01-26|上海朗帛通信技术有限公司|Method and device in user equipment and base station for wireless communication|
    US11218981B2|2018-09-20|2022-01-04|Kabushiki Kaisha Toshiba|Wireless mesh network and data transmission method|
    法律状态:
    2016-07-29| PLFP| Fee payment|Year of fee payment: 2 |
    2017-01-20| PLSC| Search report ready|Effective date: 20170120 |
    2017-07-31| PLFP| Fee payment|Year of fee payment: 3 |
    2018-07-27| PLFP| Fee payment|Year of fee payment: 4 |
    2019-07-31| PLFP| Fee payment|Year of fee payment: 5 |
    2021-04-09| ST| Notification of lapse|Effective date: 20210305 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1556794A|FR3039031B1|2015-07-17|2015-07-17|METHOD AND SYSTEM FOR MULTIPLE ACCESS WITH ADAPTIVE FREQUENCY MULTIPLEXING DATA SENDING AUTHORIZATION REQUESTS|FR1556794A| FR3039031B1|2015-07-17|2015-07-17|METHOD AND SYSTEM FOR MULTIPLE ACCESS WITH ADAPTIVE FREQUENCY MULTIPLEXING DATA SENDING AUTHORIZATION REQUESTS|
    EP16179003.5A| EP3119155B1|2015-07-17|2016-07-12|Multiple access method and system with adaptive frequency multiplexing of authorisation requests for sending data|
    US15/208,971| US10158459B2|2015-07-17|2016-07-13|Multiple access method and system with adaptive frequency multiplexing of data send authorization requests|
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