An access point is connected with surveillance cameras through wireless communication means. In the access point, a packet identification unit identifies the surveillance camera. A receiving status measurement unit measures receiving speed of the image data for each surveillance camera, and a priority apparatus determination unit determines whether to prioritize receiving of image data from a surveillance camera with the receiving speed smaller than a reference speed. The receiving control unit transmits a CTS packet, indicating that data receiving from the surveillance camera determined by the priority apparatus determination unit will be prioritized, to all of the connected surveillance cameras. The surveillance cameras other than that indicated by the CTS packet pause the data transmission to the access point when the CTS packet is received.