Abstract: A system has a first base station for performing communication with a plurality of radio terminals, and a plurality of second base stations, the first base station estimating a moving direction of each of the radio terminals, determining one of the second base stations to which the each of the radio terminals is handed over on the basis of the estimated moving direction, obtaining priority information indicating a priority of the each of the radio terminals from the each of the radio terminals, and sending out identification information of the each of the radio terminals and the priority information of the each of the radio terminals to the determined second base station, the determined second base station performing handover of the radio terminals corresponding to the identification information received from the first base station on the basis of the received priority information and the received identification information.

Abstract: In a mobile communication system in which a modulation and coding scheme is selected in accordance with reception quality information in which a terminal periodically reports to a base station, a method for causing a terminal located near the boundary of a cell to reduce its uplink transmit power by considering intercell interference and without incurring an increase in error rate. The method includes the steps of: a first base station detecting an interference level and terminal identification information identifying an interfering terminal, and transmitting interference information to all neighboring base stations; a second base station unit, as the serving base station of the terminal, receiving the interference information and transmitting control information to the terminal; and the terminal receiving the control information, reducing transmit power in accordance with the interference level, and adjusting reception quality information in such a direction so as to reduce quality.

Abstract: A system has a first base station for performing communication with a plurality of radio terminals, and a plurality of second base stations, the first base station estimating a moving direction of each of the radio terminals, determining one of the second base stations to which the each of the radio terminals is handed over on the basis of the estimated moving direction, obtaining priority information indicating a priority of the each of the radio terminals from the each of the radio terminals, and sending out identification information of the each of the radio terminals and the priority information of the each of the radio terminals to the determined second base station, the determined second base station performing handover of the radio terminals corresponding to the identification information received from the first base station on the basis of the received priority information and the received identification information.

Abstract: In a mobile communication system in which a modulation and coding scheme is selected in accordance with reception quality information in which a terminal periodically reports to a base station, a method for causing a terminal located near the boundary of a cell to reduce its uplink transmit power by considering intercell interference and without incurring an increase in error rate. The method includes the steps of: a first base station detecting an interference level and terminal identification information identifying an interfering terminal, and transmitting interference information to all neighboring base stations; a second base station unit, as the serving base station of the terminal, receiving the interference information and transmitting control information to the terminal; and the terminal receiving the control information, reducing transmit power in accordance with the interference level, and adjusting reception quality information in such a direction so as to reduce quality.

Abstract: A first PDU conversion unit converts a data string before conversion to a data string in a first data structure. A second PDU conversion unit converts a data string before conversion to a data string in a second data structure different from the first data structure. A selection unit selects one of the first PDU conversion unit and the second PDU conversion unit. A transmission unit transmits a data string obtained by the conversion by the unit selected by the selection unit, and an identification signal output from a transmission control unit as selection information indicating a selection result by the selection unit.