Patent ID: 8311019

Claim:
A radio network controller, comprising: a transmission timing adjusting unit for adjusting transmission timings of downlink frames to be sequentially transmitted from the radio network controller to a base transceiver station having a receiving window, after receiving from the base transceiver station a first timing adjustment control frame for informing of a difference between a reception timing of a downlink frame applied with a frame sequence number and an expected reception timing of the downlink frame to be received by the base transceiver station, when the downlink frame is received outside of the receiving window by the base transceiver station; a control unit for controlling a transmission schedule of the downlink frame not to change, even if another timing adjustment control frame is received in a first period that begins immediately after the transmission timing is adjusted, as a period of ignoring the timing adjustment control frame that has been received; and a changing unit for changing the first period in accordance with a change in a transmission delay between the radio network controller and the base transceiver station; wherein the first period is set to a period α plus a round-trip time, the period α being greater than 0 and smaller than a transmission interval of the downlink frames, the round-trip time being a period from a time when the downlink frame is transmitted to the base transceiver station from the radio network controller to a time when the radio network controller receives the timing adjustment control frame in response to the downlink frame.