A wireless communications system in which real-time data and burst data can be mixedly transmitted, and a transmission band can be dynamically assigned according to a state of data transmission. A master station has a scheduler for determining a transmission band assignment including information about the transmission timing of the data, a transmission amount, and a state that is allowed to access. The scheduler regularly carries out scheduling and optimizes the transmission band to be assigned dynamically according to the communication type of the data and a state of data transmission. The master station gives a transmission band assignment which is determined by the scheduler to each slave station. A transmitting station executes data transmission (access) to a receiving station based on the given transmission band assignment. The receiving station gives information about a state of data receiving to the master station, where the scheduler reflects this on scheduling.