A macrocell base station controls to reduce interference between cells by a downlink signal of the macrocell base station with specific timing, the interference which a downlink signal of a low transmission power cell suffers for a wireless terminal. A low transmission power cell base station decides measurement timing with which the wireless terminal measures reception quality of the low transmission power cell based on information about the specific timing, and sends a setting message including a parameter according to the measurement timing to the wireless terminal. The wireless terminal measures reception quality with the measurement timing indicated by the parameter, and when the wireless terminal satisfies a condition for executing an event based on the measured result, the wireless terminal sends a reception quality measurement message including information indicating that the measurement is made with the measurement timing to the low transmission power cell base station.