a transceiver; and

circuitry that:

performs a data element setting that sets a first series of sequence numbers to each data element of a first data stream, a second series of sequence numbers to each data element of a second data stream and a third series of sequence numbers to each data element of a third data stream to be transmitted to one transmission destination,

wherein each data element of the first data stream has a first priority, each data element of the second data stream has a second priority different from the first priority, each data element of the third data stream has a third priority different from the first and second priorities;

performs a sequential transmission of the first and second data streams to the one transmission destination through first through third frequency bands of a plurality of frequency bands;

transmits a request for receipt acknowledgment information only through a specific frequency band of the first through third frequency bands in which the corresponding sequential transmission is expected to be completed first, the request transmitted after the corresponding sequential transmission has completed, and before completion of the corresponding transmissions on each of the plurality of frequency bands other than the specific frequency band; and

receives the receipt acknowledgment information via the specific frequency band, the receipt acknowledgment information indicating a receipt acknowledgment regarding the data transmitted through the specific frequency band.