A retransmission control method involving a physical control channel transmitting step of transmitting, at a transmitting side apparatus, a new data indicator updated upon transmission of a new packet, and a retransmission sequence number indicating whether transmission is first transmission or retransmission, through a physical control channel associated with a physical data channel, and a transmission acknowledgement information transmitting step of transmitting, at a receiving side apparatus, transmission acknowledgment information on a packet received through the physical data channel, on the basis of the new data indicator and the retransmission sequence number received through the physical control channel.