In order to control the use of physical radio resources, the physical radio resources are divided into chronologically consecutive frames (14), so that a frame contains slots (16, 17, 18) of various sizes, which slots represent a given share of the physical radio resources contained in the frame and can be individually allocated to different radio connections. The first dimension of a frame is time and the second dimension can be time, frequency or code. In the direction of the second dimension the slots represent various sizes, and a given first integral number of slots of the first size can be modularly replaced by another integral number of slots of another size. A certain number of consecutive frames form a superframe (19), in which case frames with corresponding locations in consecutive superframes are equal in slot division and allocations, if the data transmission demands do not change. Changes in the state of occupancy of the slots are possible at each superframe. In order to form an uplink connection, the mobile station sends a capacity request, where it indicates the type of requested connection and the demand of resources. In order to form a downlink connection, the base station subsystem sends a paging call, where it indicates the location in the superframe of the slots allocated to the connection. In order to indicate the state of occupancy, the base station subsystem maintains a superframe-size parametrized reservation table.