Frames exchanged between a control unit and a radio terminal via base stations are encapsulated, with timestamping information, in frames over an asynchronous interface between the control unit and each station. The timestamping information accompanying a data frame over the asynchronous interface indicates an instant of transmission of the said frame by each station according to a time counter specific to the radio section of the connection. The information accompanying an acknowledgement frame over the asynchronous interface indicates an instant of reception of the said frame by each station according to the said time counter. On reception of an acknowledgement frame accompanied by a timestamping information element indicating an instant of reception and indicating the non-reception by the terminal of the said data frame, the reception of the acknowledgement frame is selectively taken into account for the retransmission of the said data frame.