A method for multiple access to a frequency band of a communication channel in a communication network with carrier sensing and collision avoidance, wherein the frequency band is divided into a set of request-to-send sub-bands (SB0, SB1,..., SBi,...SBn) dedicated to the transmission, by source nodes to a destination node, of request-to-send messages (RST NS0, RTS NS1) for communicating data on the frequency band, comprising: - implementing the multiple access to the frequency band divided into a first number of request-to-send sub-bands during a first time window, and evaluating the bitrate of the data sent on the frequency band during the first time window, - modifying the division of the frequency band, implementing the multiple access to the frequency band divided into a second number of request-to-send sub-bands during a second time window, and evaluating the bitrate of the data sent on the frequency band during the second time window, - comparing the bitrate of the data sent on the frequency band during the first time window with the bitrate of the data sent on the frequency band during the second time window, - modifying the division of the frequency band consisting in increasing or reducing the number of request-to-send sub-bands depending on the result of the bitrates comparing, said modifying consisting in modifying the number of request-to-send sub-bands from the second number to the first number when the bitrate during the first time window is greater than the bitrate during the second time window, and - when the bitrate during the first time window is greater than the bitrate during the second time window, the steps consisting in widening the first time window and implementing the multiple access to the frequency band divided into said first number of request-to-send sub-bands during the first widened time window. - implementing the multiple access to the frequency band divided into a first number of request-to-send sub-bands during a first time window, and evaluating the bitrate of the data sent on the frequency band during the first time window, - modifying the division of the frequency band, implementing the multiple access to the frequency band divided into a second number of request-to-send sub-bands during a second time window, and evaluating the bitrate of the data sent on the frequency band during the second time window, - comparing the bitrate of the data sent on the frequency band during the first time window with the bitrate of the data sent on the frequency band during the second time window, - modifying the division of the frequency band consisting in increasing or reducing the number of request-to-send sub-bands depending on the result of the bitrates comparing, said modifying consisting in modifying the number of request-to-send sub-bands from the second number to the first number when the bitrate during the first time window is greater than the bitrate during the second time window, and - when the bitrate during the first time window is greater than the bitrate during the second time window, the steps consisting in widening the first time window and implementing the multiple access to the frequency band divided into said first number of request-to-send sub-bands during the first widened time window.