Data transmission is performed using the most suitable data rate for the radiation pattern of an antenna. Using an individual pilot channel of a first slot, a base station transmits a pilot signal in a specified direction with a beam pattern having narrow directivity. A wireless terminal located in that direction receives the pilot signal and determines a data rate according to the reception quality of the pilot signal. The wireless terminal transmits to the base station a signal requesting the determined data rate. The base station receives that signal and, based on the requested data rate, transmits data to the wireless terminal with a beam pattern in the same direction as the direction in which the pilot signal was transmitted, using a data channel of a second slot, which occurs a predetermined number of slots after the first slot.