A control unit aggregates packets which are to be sent to one or more terminal apparatuses, and produces aggregated packets. The control unit divides a certain period into a plurality of partial periods, allots each of the plurality of partial periods to any of the plurality of terminal apparatuses and produces a control signal with which to convey an assignment condition to the terminal apparatus. In the case of an aggregated packet where the packets for the plurality of terminals are aggregated, a baseband processing unit and the like transmit the aggregated packet together with the control signal to the plurality of terminal apparatuses. In the case of an aggregated packet where the packets for a single terminal are aggregated, they transmit the aggregated packet to the plurality of terminal apparatuses, without sending the control signal.