An image acquisition unit acquires an image that includes a figure of the user wearing a head-mounted display. A narrowed-down region specification unit specifies, within the image, a region that includes a figure of the head of the user when a posture of the user stretches in a vertical direction. A secondary candidate sector selection unit selects, from among primary candidates of a plurality of the main beam directions, secondary candidates that are directions made to be correspondent to positions within the region. A sector-level sweep processing execution unit determines, from among the secondary candidates, a main beam direction for communication with the head-mounted display. The region has a projection part.