A sender for a communications system transmits data as packets to a receiver. The receiver transmits quality values to the sender representing the reception quality of packets received with errors. The receiver stores information regarding a number of received data packets, and there is a relay transceiver between the sender and the receiver. Both the relay transceiver and the sender can encode data packets into composite packets, and to transmit composite packets to the receiver. The stored information in the receiver comprises the data in correctly received packets and information regarding the reception quality of packets received with errors and the data of those packets, and the stored information is used by the receiver to decode composite packets, thereby extracting the data in the packets of the composite packets.