Transmission parameter change control method and a radio base station

A disclosed method of controlling a change of a transmission parameter including the steps of generating a control data unit which does not include a specification of the change timing for changing a parameter value of the transmission parameter for which processing all within a certain layer or sublayer is possible; transmitting the control data unit only in a first half of a transmission frame; and conducting transmission and/or reception, at a timing of a frame following a frame in which the control data unit was transmitted, based on the changed transmission parameter.