A base station apparatus for communicating to a mobile station over an uplink shared channel includes a transmit instruction unit configured to assign an uplink shared channel to the mobile station and instruct the mobile station to conduct transmissions over the assigned uplink shared channel; a measurement unit configured to measure a radio quality of the assigned uplink shared channel; and a determination unit configured to determine based on the radio quality whether the mobile station has transmitted data over the assigned uplink shared channel. In addition, a communication control method at a base station apparatus for communicating to a mobile station over an uplink shared channel includes assigning an uplink shared channel to the mobile station and instructing the mobile station to conduct transmissions over the assigned uplink shared channel; measuring a radio quality of the uplink shared channel assigned to the mobile station; and determining based on the radio quality whether the mobile station has transmitted data over the assigned uplink shared channel.