A radio communications system and method in which at least one base station (BS1) also contains a transceiver in order to transmit and receive by various radio transmission modes (DECT, GSM, UMTS), and in which the base station (BS1) is connected to a controller (RRM) which determines an availability value for each of the various radio transmission modes (DECT, GSM, UMTS) with the aid of preselectable criteria and controls the base station (BS1) in order to transmit to a wireless subscriber terminal (MT) an identification code at least for the radio transmission mode (DECT) which has the highest availability value. At least the radio transmission mode (DECT) which has the best instantaneous availability in the coverage area of the base station (BS1) is offered to the subscriber terminal (MT) by the base station (BS1). The controller (RRM) connected to all base stations can carry out this function centrally in order to utilize the radio resources of the entire system, which is preferably designed as multi-standard system.