The traffic of wireless communication between wireless access points can be lowered without requiring a change in the access point to which an associated station belongs, to thereby efficiently use a band for the wireless communication. For this purpose, (1) a station sends a packet, and a wireless access point and a wired access point receives the packet; (2) the wired access point stores an identifier indicating proxy transmission in an ACK packet and then transmits the ACK packet, and (3) the wireless access point confirms the proxy processing identifier of the ACK packet from wired access point and stops delivery of packets to the backhaul. The wired access point delivers the packet to a destination of the packet.