When a radio terminal (200) receives interference from a small-cell base station (300), a large-cell base station (100) sends, to the small-cell base station (300), band use restriction information indicating a band with restricted use which is a frequency band, in which the use thereof needs to be restricted by the small-cell base station (300). In this instance, the large-cell base station (100) sets the upper and lower limit for the band with restricted use so that the upper and lower limit thereof match the limit of an S-CQI measured unit band.