A method for adaptive communication in an HF frequency band, comprising the following steps: ∘ determining (310, 312) a useful sub-band S that is available for transmission in the HF band as a function of at least one of the following two criteria: ▪ the number of frequencies allocated to the user included in the useful sub-band S according to said frequency allocation plan; ▪ the physical availability of the useful sub-band S that is assessed as a function of a prediction of any interference induced on the signal by the reflections on the ionospheric layers; ∘ selecting (311, 313, 314, 315) from the useful sub-band S a set of n frequency channels of identical width as a function of a frequency allocation plan and of the quality of the link of each of said channels; ∘ simultaneously transmitting on the n frequency channels a signal having an HF waveform, said method being characterised in that: ∘ the quality of the link of each of said channels is estimated at least on the basis of the following sub-steps: ▪ measuring the power of the received signal, in the absence of communication, in each frequency channel that makes up the useful sub-band S; ▪ attributing a quality score to each of said frequency channels as a function of the comparison of said power to one or more predetermined thresholds, said quality decreasing with the increase in the power; ▪ selecting the n channels having the highest quality scores; ∘ said method further comprising the following test step: ▪ determining the number of frequency channels, for which the quality of the link is higher than a minimum threshold that is required in order for a transmission to be possible on these channels; ▪ determining a further available useful sub-band S if said number is lower than the number n of channels required for the transmission. ∘ determining (310, 312) a useful sub-band S that is available for transmission in the HF band as a function of at least one of the following two criteria: ▪ the number of frequencies allocated to the user included in the useful sub-band S according to said frequency allocation plan; ▪ the physical availability of the useful sub-band S that is assessed as a function of a prediction of any interference induced on the signal by the reflections on the ionospheric layers; ∘ selecting (311, 313, 314, 315) from the useful sub-band S a set of n frequency channels of identical width as a function of a frequency allocation plan and of the quality of the link of each of said channels; ∘ simultaneously transmitting on the n frequency channels a signal having an HF waveform, ▪ the number of frequencies allocated to the user included in the useful sub-band S according to said frequency allocation plan; ▪ the physical availability of the useful sub-band S that is assessed as a function of a prediction of any interference induced on the signal by the reflections on the ionospheric layers; ∘ selecting (311, 313, 314, 315) from the useful sub-band S a set of n frequency channels of identical width as a function of a frequency allocation plan and of the quality of the link of each of said channels; ∘ simultaneously transmitting on the n frequency channels a signal having an HF waveform, ∘ the quality of the link of each of said channels is estimated at least on the basis of the following sub-steps: ▪ measuring the power of the received signal, in the absence of communication, in each frequency channel that makes up the useful sub-band S; ▪ attributing a quality score to each of said frequency channels as a function of the comparison of said power to one or more predetermined thresholds, said quality decreasing with the increase in the power; ▪ selecting the n channels having the highest quality scores; ▪ measuring the power of the received signal, in the absence of communication, in each frequency channel that makes up the useful sub-band S; ▪ attributing a quality score to each of said frequency channels as a function of the comparison of said power to one or more predetermined thresholds, said quality decreasing with the increase in the power; ▪ selecting the n channels having the highest quality scores; ∘ said method further comprising the following test step: ▪ determining the number of frequency channels, for which the quality of the link is higher than a minimum threshold that is required in order for a transmission to be possible on these channels; ▪ determining a further available useful sub-band S if said number is lower than the number n of channels required for the transmission. ▪ determining the number of frequency channels, for which the quality of the link is higher than a minimum threshold that is required in order for a transmission to be possible on these channels; ▪ determining a further available useful sub-band S if said number is lower than the number n of channels required for the transmission.