A retransmission control method according to the present invention includes; transmitting, at a transmitter side apparatus 10, a new data indicator configured of multiple bits and updated when a new packet is transmitted, through a physical control channel associated with the physical data channel; and transmitting, at the receiver side apparatus 30, the transmission acknowledgment information, without depending on a decoding result of the packet received through the physical data channel, when the new data indicator received through the physical control channel is different from a new data indicator which has been expected to be received next at the receiver side apparatus.