A method for allocating time-frequency resources to data packets for transmitting said data packets via a communications network in which communications are performed over a frequency selective channel, the method being performed by a scheduler device of the communications network, the method comprising at least one iteration of steps comprising: - obtaining data packets to be transmitted, or descriptions thereof, each data packet being either a latency-constrained data packet or another data packet; the method being characterized in that said iteration further comprises: - obtaining information representative of transmission conditions for each channel over which at least one obtained data packet has to be transmitted; - for each latency-constrained data packet, determining (S403,S411) each candidate time-frequency resource that can be used for transmitting said latency-constrained data packet, on the basis of the obtained information representative of transmission conditions and of a latency constraint associated with said latency-constrained data packet; - determining whether the quantity of at least one time-frequency resource needed for transmitting said at least one latency-constrained data packet is equal to the quantity of determined candidate time-frequency resources for said at least one latency-constrained data packet; - allocating at least one time-frequency resource among said candidate time-frequency resources to respective at least one latency-constrained data packet, when the scheduler device has determined that the quantity of at least one time-frequency resource needed for transmitting said at least one latency-constrained data packet is equal to the quantity of determined candidate time-frequency resources for said at least one latency-constrained data packet; - reserving at least one time-frequency resource for transmitting respective at least one other data packet, when the scheduler device has not allocated any candidate time-frequency resource to any latency-constrained data packet in the preceding step. - obtaining data packets to be transmitted, or descriptions thereof, each data packet being either a latency-constrained data packet or another data packet; - obtaining information representative of transmission conditions for each channel over which at least one obtained data packet has to be transmitted; - for each latency-constrained data packet, determining (S403,S411) each candidate time-frequency resource that can be used for transmitting said latency-constrained data packet, on the basis of the obtained information representative of transmission conditions and of a latency constraint associated with said latency-constrained data packet; - determining whether the quantity of at least one time-frequency resource needed for transmitting said at least one latency-constrained data packet is equal to the quantity of determined candidate time-frequency resources for said at least one latency-constrained data packet; - allocating at least one time-frequency resource among said candidate time-frequency resources to respective at least one latency-constrained data packet, when the scheduler device has determined that the quantity of at least one time-frequency resource needed for transmitting said at least one latency-constrained data packet is equal to the quantity of determined candidate time-frequency resources for said at least one latency-constrained data packet; - reserving at least one time-frequency resource for transmitting respective at least one other data packet, when the scheduler device has not allocated any candidate time-frequency resource to any latency-constrained data packet in the preceding step.