A wireless base station apparatus configured to establish a wireless connection with a first terminal equipment, the wireless base station apparatus comprising: a detection unit configured to detect an intensity of a signal transmitted from a second terminal equipment other than the first terminal equipment; and a power calculation unit configured to calculate, as a downlink transmission power of a data channel to be sent to the first terminal equipment, a sum of a first parameter adjusted at an interval of predetermined time and a second parameter taking a value between a predetermined first minimum value and a predetermined first maximum value, wherein the power calculation unit is configured: when it is detected that that reception power of the signal transmitted from the second terminal equipment is equal to or larger than a predetermined value, to set, as the second parameter, a larger value of the predetermined first minimum value and a difference between a first downlink transmission target power and the first parameter, wherein the first downlink transmission target power is reduced when the second terminal equipment is detected, and when the first parameter is adjusted at the interval of predetermined time, to further set a difference between the first downlink transmission target power and the predetermined first minimum value as the first parameter and the predetermined first minimum value as the second parameter. a detection unit configured to detect an intensity of a signal transmitted from a second terminal equipment other than the first terminal equipment; and a power calculation unit configured to calculate, as a downlink transmission power of a data channel to be sent to the first terminal equipment, a sum of a first parameter adjusted at an interval of predetermined time and a second parameter taking a value between a predetermined first minimum value and a predetermined first maximum value, wherein the power calculation unit is configured: when it is detected that that reception power of the signal transmitted from the second terminal equipment is equal to or larger than a predetermined value, to set, as the second parameter, a larger value of the predetermined first minimum value and a difference between a first downlink transmission target power and the first parameter, wherein the first downlink transmission target power is reduced when the second terminal equipment is detected, and when the first parameter is adjusted at the interval of predetermined time, to further set a difference between the first downlink transmission target power and the predetermined first minimum value as the first parameter and the predetermined first minimum value as the second parameter. when it is detected that that reception power of the signal transmitted from the second terminal equipment is equal to or larger than a predetermined value, to set, as the second parameter, a larger value of the predetermined first minimum value and a difference between a first downlink transmission target power and the first parameter, wherein the first downlink transmission target power is reduced when the second terminal equipment is detected, and when the first parameter is adjusted at the interval of predetermined time, to further set a difference between the first downlink transmission target power and the predetermined first minimum value as the first parameter and the predetermined first minimum value as the second parameter.