A first apparatus 101 and a second apparatus 102 carry out wireless data communication using a wireless transmission path that uses a plurality of physical links in parallel. In each of the apparatuses, input/output ports 111 to 113 input and output data. A plurality of wireless signal processing means 141 to 143 respectively control different ones of the physical links. The wireless signal processing means 141 to 143 respectively measure reception signal levels of the physical links, and notify a counterpart apparatus about the reception signal levels. Link aggregation control means 130 determines a priority for each of the physical links based on the signal level for each of the physical links. The packet transfer processing means 141 to 143 select, out of the physical links structuring the wireless transmission path, the physical link having a usable band of a prescribed capacity and high priority as the data recipient.