This invention is characterized by a communication system comprising a station with a diversity function and an access point. The station notifies the access point that the station is in a power saving mode during antenna evaluation and, when the antenna evaluation is complete, notifies the access point of the end of the power saving mode. When recognizing that the station is in the power saving mode, the access point stops transmitting the data packet. Thus, the situation in which when a diversity function executes an antenna evaluation process, repetition of retransmission of a data packet, thereby disconnecting communication, is avoided.