In a radio communication system having a data channel for the transmission of data packets from a primary station to a secondary station, a plurality of downlink control channels are used to signal information relating to packet transmission. A problem with this scheme is that with a fixed control channel allocation system throughput (T) for a given offered load (O) can be significantly reduced in a worst case scenario (for example two secondary stations using the same control channel). One solution uses an indicator signal to inform a secondary station of the control channel it should receive, but this adds significant complexity to the system. The present invention provides a simpler scheme having similar benefits by shuffling the allocation of control channels to secondary stations, according to a defined sequence for each secondary station, thereby avoiding the worst case scenario.