A communication system is provided in which a communication node can allocate resources, for another communication node, within a number of consecutive subframes using a single control message. The other communication node receives codewords transmitted over using the allocated resources, aggregates ACK/NACK feedback for the received codewords and transmits the aggregated ACK/NACK feedback to the communication node for use in controlling subsequent transmission of new codewords or retransmission of previous codewords.