Transmission of data frames over a channel in a communications network takes place on a slotted time base. A method comprises an evaluation, by at least one node of the network having a frame available for transmission, of whether the channel is available for transmission. If the channel is available for transmission, the available frame is transmitted over the channel in a subsequent slot of the slotted time base. If the channel is not available for transmission, owing to a frame (having a certain temporal length) being transmitted over the channel at a certain time, the slotted time base of the node is resynchronized as a function of the frame being transmitted. The resynchronization includes identifying, as a function of the certain temporal length, an interval of delay to evaluate again at a future time whether the channel is available for transmission.