With radio-transmission apparatus, in order to control the rate of packet data transmitted between a master and slaves adaptively to the quality of an RF channel, a slave controls, when having received packet data, error detection to detect a reception error in the packet data. On the basis of the reception error detected, the quality of the packet data transmitted is determined. In response to the resultant quality thus determined, the slave generates a command instructing the master, sending out packet data, to alter a sort of packets to transmit the command to the master. The master alters the sort of packets as instructed by the command.