Abstract: A base station assigns a most appropriate carrier from wide frequency bands in response to a re-request for channel establishment received from a mobile station, even if a same slot as a slot last assigned is assigned. Furthermore, a frequency management table is managed in which carriers that form a radio channel and are grouped by a specific number thereof so as to be distributed over wide frequency bands. Priorities used to search groups are individually provided for base stations that form a system. This allows neighboring base stations to distribute carriers over the wide frequency bands.

Abstract: In a communications system including a base station capable of altering a frequency bandwidth which is used for transmitting broadcast data for providing point-to-multipoint broadcasting communications service and which is used for transmitting individual communications data for providing point-to-point individual communications service, and a mobile terminal capable of altering a receivable bandwidth which is used for receiving at least the broadcast data and the individual communications data transmitted from the base station, decision processing of making a decision as to whether the mobile terminal can receive reception-desired content it desires to receive among contents provided by the broadcasting communications service is executed in accordance with a frequency occupying bandwidth used for transmitting the reception-desired content. Thus, the mobile terminal becomes able to make a decision as to whether it can receive particular E-MBMS content considering its own UE position.

Abstract: A data-transmission control method is implemented when transmitting data after dividing the data into a plurality of blocks and performing error correction when performing data transmission. The method includes obtaining additional information indicating a result of error correction process of received data and a result of data transmission (ACK/NACK) from a reception station, and deciding a data length of data to be retransmitted when NACK is obtained as the result of data transmission so that a rate of occurrence of transmission errors upon retransmission is minimized, based on a number of blocks in which error correction has failed indicated by the additional information.

Abstract: A mobile terminal judges whether or not the mobile terminal is able to make a transition to a DTX period during Active, and, when judging that the mobile terminal is able to make a transition to a DTX period during Active, notifies a base station to that effect. If the base station judges that the mobile terminal is able to make a transition to a DRX period during Active when triggered by the notification from the mobile terminal, the base station temporarily stops supply of electric power to the data transmission processing units and the data reception processing units of the mobile terminal.

Abstract: Since OFDM (Orthogonal Frequency Division Multiplexing), which is a downlink access scheme used for an LTE (Long Term Evolution) communication system, is weak at interference, it is preferable that the number of base stations for transmitting the same E-MBMS (Evolved Multimedia Broadcast Multicast Service) data be not excessive. Thus, the mobile terminal performs: processing of obtaining measurement quality values by measuring reception quality of each base station; processing of deciding on whether the measurement quality value of a serving base station exceeds a certain receiving level; processing of adding measurement quality values of other base stations to the measurement quality value of the serving base station until the sum exceeds the certain receiving level; and processing of notifying the serving base station of the serving base station and other base stations as candidates for an active set for E-MBMS.

Abstract: A base station assigns a most appropriate carrier from wide frequency bands in response to a re-request for channel establishment received from a mobile station, even if a same slot as a slot last assigned is assigned. Furthermore, a frequency management table is managed in which carriers that form a radio channel and are grouped by a specific number thereof so as to be distributed over wide frequency bands. Priorities used to search groups are individually provided for base stations that form a system. This allows neighboring base stations to distribute carriers over the wide frequency bands.