A method for managing the HF frequencies in a broadband communication network, comprises the following steps: determining the range of passing frequencies for a user for a given link and SLA service; establishing the set of authorized frequencies S″ in the transmission range of the user with the different power and modulation configurations for each frequency; analyzing the received spectrum in order to determine the frequency or frequencies already used and deciding, on the basis of their associated usage type, whether they must be excluded; for each possible frequency fl of the set S′″, determining the necessary power , i=1 . . . N, j=1 . . . m for each of the m possible rate/waveform configurations, taking into account the power limit on each frequency fl; allocating the frequencies fl of the set S′″ to the different users, their modulation and their power, by taking account of multi-carrier constraints.