Abstract: Provided is a communication system including a control station and a satellite repeater capable of forming two or more beams. The control station includes a control unit that classifies the two or more beams into clusters each made up of two or more beams among the two or more beams and allocates different frequencies to the beams belonging to one of the clusters. The satellite repeater includes a channelizer that performs exchanging processing on an input reception signal and outputs the reception signal having undergone the exchanging processing, as a transmission signal. A signal used in the exchanging processing includes a signal obtained by combining signals corresponding to the beams defining the one cluster.

Abstract: Provided is a communication system including a control station and a satellite repeater capable of forming two or more beams. The control station includes a control unit that classifies the two or more beams into clusters each made up of two or more beams among the two or more beams and allocates different frequencies to the beams belonging to one of the clusters. The satellite repeater includes a channelizer that performs exchanging processing on an input reception signal and outputs the reception signal having undergone the exchanging processing, as a transmission signal. A signal used in the exchanging processing includes a signal obtained by combining signals corresponding to the beams defining the one cluster.

Abstract: A transmitting station includes a transmitting antenna whose orientation direction is changeable, and a controller that controls the orientation direction of the transmitting antenna according to an orientation direction of the transmitting antenna determined together with receiving stations to receive data transmitted from the transmitting antenna based on estimate values of received signal quality at receiving stations that are candidates for receiving stations to receive data transmitted from the transmitting antenna. The transmitting station can maintain received signal quality at a plurality of receiving stations at a desired value or more in a data transmission system.

Abstract: A transmitting station includes a transmitting antenna whose orientation direction is changeable, and a controller that controls the orientation direction of the transmitting antenna according to an orientation direction of the transmitting antenna determined together with receiving stations to receive data transmitted from the transmitting antenna based on estimate values of received signal quality at receiving stations that are candidates for receiving stations to receive data transmitted from the transmitting antenna. The transmitting station can maintain received signal quality at a plurality of receiving stations at a desired value or more in a data transmission system.

Abstract: When a transmission request for new data is issued under a situation where a plurality of data are transmitted to a specific service area from a plurality of service areas, a feeder link station searches an available frequency to be allocated to the new data in a down-link frequency band of the specific service area, and when any of data communications is completed, allocates a down-link frequency band used in the data communication as a down-link frequency band for the new data. A satellite repeater arranges the new data on the down-link frequency band right after the data communication is completed following a relay control by the feeder link station.

Abstract: When a transmission request for new data is issued under a situation where a plurality of data are transmitted to a specific service area from a plurality of service areas, a feeder link station searches an available frequency to be allocated to the new data in a down-link frequency band of the specific service area, and when any of data communications is completed, allocates a down-link frequency band used in the data communication as a down-link frequency band for the new data. A satellite repeater arranges the new data on the down-link frequency band right after the data communication is completed following a relay control by the feeder link station.