Radio network controller includes a propagation delay acquisition part for acquiring a measurement value of a round-trip time between the base station device and the radio terminal, an offset acquisition part for acquiring an offset value indicating a delay at which the base station device transmits the information of transmitting power control to the radio terminal, from a reference timing, a channelization format determination part for determining the channel identification spread code transmitted to the base station device based on the measurement value of the round-trip time and the offset value acquired by the offset acquisition part, and a slot format determination part for determining the time slot information transmitted to the base station device based on the measurement value of the round-trip time and the offset value.