Abstract: A wireless communication monitoring system for monitoring a hardware failure of a wireless communication unit of a wireless communication device using a remote monitoring control device, in which the wireless communication device transmits or receives a predetermined radio signal to or from a monitoring device added or attached to the host device to perform a life and death check for checking an operation, and the remote monitoring control device detects a hardware failure of the wireless communication unit of the wireless communication device on the basis of a result of the life and death check received from the wireless communication device. This makes it possible to detect a failure that cannot be detected from information obtained from a device state request to a wireless communication device of the related art.

Abstract: A reflector antenna includes: a radiator that radiates a radio wave; a main reflector that reflects the radio wave radiated from the radiator in a communication direction; an expansion panel that is attached to at least a part of the main reflector to increase an area of the main reflector; and a first adjustment unit that changes a position of the radiator, or a second adjustment unit that replaces the radiator with a radiator having a different radiation angle. This configuration makes it possible to implement a large-aperture antenna having excellent transportability and operability without preparing another antenna having a large aperture and replacing a standard antenna.

Abstract: In a wireless communication system that performs a wireless communication by performing band division into a plurality of sub-spectra, a transmission device includes a band division unit and a transmission gain control unit configured to control a transmission gain of each of transmission signals of a plurality of sub-spectra for each sub-spectrum in accordance with information that is related to a power density of each sub-spectrum and fed back from a reception device so that the power density of each of reception signals of the plurality of sub-spectra on the reception device is uniform, and the reception device includes a reception power density detection unit configured to detect the power density of each of the plurality of sub-spectra to be received, a feedback unit configured to feed back information regarding the power density to the transmission device, and a band synthesis unit. Thus, it is possible to avoid deterioration of signal quality in hand division and synthesis transmission.

Abstract: In a line control apparatus including a shared band in which first and second frequency bands used by first and second wireless communication systems, respectively, overlap with each other and allocating the first and second frequency bands including the shared band to terminal stations of the respective wireless communication systems, the line control apparatus includes a control unit configured to identify a use status of the first and second frequency bands, and release an allocated band of a terminal station of the second wireless communication system, the terminal station being a minimum terminal station necessary, in a case where a terminal station of the first wireless communication system performs a new band allocation request, and a requested band by the first wireless communication system is not secured due to allocation of the shared band to the terminal station of the second wireless communication system, until the requested band is secured.

Abstract: A satellite communication system communicates via a communication satellite using one of a plurality of portable station devices as a master station device and another portable station device as a slave station device. The master station device transmits a first control signal for the slave station device to establish synchronization. The master station device determines that the slave station device is in a communicable state by a second control signal received from the slave station device that has received the first control signal and established synchronization. The master station device selects one of at least one slave station devices in a communicable state and transmits a third control signal for instructing start of transmission of a communication signal to the selected slave station device and the subject device. Due to this, it is possible to connect a channel between portable station devices without the intervention of a control station device or a regulation station device.

Abstract: A portable station device performs: a coarse adjustment to the antenna direction of a target communication satellite, the antenna direction being calculated based on the longitude of the target communication satellite from satellite information about the longitudes of communication satellites, a beacon signal, and a telemetry signal and the installation location of the portable station device; measurement of the frequencies of the beacon signal and the telemetry signal; determination of whether the measured frequencies of the beacon signal and the telemetry signal are correct or not with reference to the frequencies of the beacon signal and the telemetry signal of the target communication satellite in the satellite information; and a fine adjustment on the antenna direction such that the beacon signal received in the coarsely adjusted antenna direction reaches the highest reception level, if the determination is correct.

Abstract: A first offset compensator configured to compensate for frequency offsets occurring during communications between a plurality of communication devices and a relay device, wherein when the first offset compensator is provided on the relay device, the first offset compensator gives a statistical frequency offset obtained from a statistic of a plurality of frequency offsets occurring during communications between respective ones of the plurality of communication devices and the relay device to a receiver configured to receive wireless signals transmitted from respective ones of the plurality of communication devices, and when the first offset compensator is provided on each of the plurality of communication devices, the first offset compensator gives a frequency offset occurring during communications between the communication device provided with the first offset compensator and the relay device to a transmitter configured to transmit wireless signals to the relay device.

Abstract: A wireless communication system includes one or more communications apparatuses, and a relay device, which is mobile, wherein the relay device includes a transmission unit adapted to transmit a channel change signal to the one or more communications apparatuses, the channel change signal containing channel information that indicates results corresponding to interference levels of a plurality of channels in a frequency band available for use in uplink transmission from the one or more communications apparatuses to the relay device and specifying information used to specify a communications apparatus subject to channel change, and the one or more communications apparatuses include a channel set unit adapted to set a channel having an interference level lower than a threshold as a channel to be used for communications with the relay device when the specifying information contained in the channel change signal is applicable.

Abstract: An antenna orientation deciding method in a wireless communication system that has a communication device provided with an antenna having directionality and a relay device that travels, includes a deciding step of deciding an orientation at which the directionality of the antenna as to the relay device is optimal, on the basis of position information of the communication device, orbit information of the relay device, and information relating to orientation of directionality of the antenna.

Abstract: In a wireless communication system in which a relay device provided on a mobile object communicates wirelessly with a plurality of communication devices present in places different from each other, each of the communication devices includes a communication device transmission unit which transmits test signals at a plurality of timings during a time frame when communication with the relay device is possible, a communication device reception unit which receives, from the relay device, communication situation information indicating communication situations at the plurality of timings, and a communication device control unit which controls the communication device transmission unit such that the communication device transmission unit communicates with the relay device at one of the plurality of timings, the communication situation of which is good and which is identified on the basis of the communication situation information, and the relay device includes a relay device reception unit which receives the respecti

Abstract: A wireless communication system includes: a first wireless communication apparatus; and a second wireless communication apparatus. First wireless communication apparatus wirelessly communicates with second wireless communication apparatus using one or more first antennas. Second wireless communication apparatus wirelessly communicates with the first wireless communication apparatus using one or more second antennas.

Abstract: In a wireless communication system that includes a base station, a plurality of relay stations that are moving, and a plurality of terminal stations in a service area, and performs downlink multiple access from the base station to each of the plurality of terminal stations via one or more relay stations of the plurality of relay stations, the base station includes a downlink multiple access unit configured to identify a relay station of the plurality of relay stations transmitting a signal receivable in the service area based on positions of the plurality of relay stations, frequency multiplex-transmit a data signal in a different frequency band to each of the plurality of terminal stations via the relay station, and spatial multiplex-transmit a data signal to a terminal station of the plurality of terminal stations supporting spatial multiplex transmission in a particular frequency band and via the plurality of relay stations.

Abstract: A relay device provided in a moving body and communicating with a plurality of communication devices present at different locations in a wireless manner includes a reception unit that receives a signal transmitted from each of the plurality of communication devices, a measurement unit that measures a degree of congestion of communication in the reception unit, and a transmission unit that transmits information to each communication device when the relay device is located in a range in which the relay device is able to communicate with the communication device, the information being used to determine the number of times of transmission of the signal to be transmitted from the communication device and being based on the degree of congestion.

Abstract: A mobile relay apparatus includes a first signal reception unit, a storage unit, and a second signal transmission unit. The first signal reception unit receives a first signal wirelessly transmitted by a first communication apparatus. The storage unit stores waveform data indicating a waveform of the first signal. The second signal transmission unit wirelessly transmits a second signal indicating the waveform data stored in the storage unit at a timing at which communication with the second communication apparatus is possible. The second communication apparatus includes a second signal reception unit, a second signal reception processing unit, and a first signal reception processing unit. The second signal reception unit receives a second signal. The second signal reception processing unit performs processing of receiving the second signal to acquire waveform data.

Abstract: A wireless communication apparatus includes an encoding unit, an interleaving processing unit, a modulation unit, and a transmission unit. The encoding unit divides a bit string to be transmitted to a communication destination apparatus which is a wireless communication apparatus at a communication destination in a predetermined period into a plurality of blocks and performs error correction coding for each of the plurality of blocks to generate encoded data.

Abstract: In a wireless communication system in which a relay apparatus provided in a mobile object wirelessly communicates with a plurality of communication apparatuses placed at different locations, the relay apparatus includes a receiver that receives a signal transmitted from each of the plurality of communication apparatus, the signal including position information indicating a position of each communication apparatus, a measurement unit that measures a congestion level of communication, a control unit that divides a communication target area into a plurality of small areas in accordance with the positions of the plurality of communication apparatuses and the congestion level of communication and generates area information indicating a position of each of the small areas, and a transmitter that sequentially transmits a plurality of pieces of the area information when the relay apparatus is positioned in a range in which the relay apparatus can communicate with the communication apparatuses, and each communication

Abstract: A relay apparatus includes a reception unit, a storage unit, and a transmission unit. The reception unit receives data wirelessly transmitted by a first communication apparatus through a plurality of first antennas. The storage unit wirelessly transmits the data received by the reception unit to a second communication apparatus through a plurality of second antennas. The second communication apparatus includes a relay data reception unit. The relay data reception unit receives data wirelessly transmitted by the relay apparatus through a plurality of third antennas.

Abstract: Provided is a transmission radio wave checking method for a satellite communication system provided with a portable station, wherein the portable station executes a transmission process of transmitting a test signal and a control signal with a first polarization at a designated transmit level to a communications satellite, a reception process of receiving the test signal and the control signal transmitted back from the communications satellite with a second polarization orthogonal to the first polarization, and a control process of starting the transmission of the test signal and the control signal with the first polarization at a transmit level lower than a predetermined value, and raising the transmit level to a predetermined value while checking whether or not the test signal and the control signal received back from the satellite conform to a predetermined condition.

Abstract: A satellite communication earth station includes a detection unit that detects a longitude, a latitude, an altitude, an azimuth, and an inclination of the antenna, a drive unit that drives the antenna to adjust the azimuth angle, the elevation angle, and the polarization angle of the antenna to the communication satellite, a determination unit that determines whether the longitude, the latitude, the altitude, the azimuth, or the inclination detected by the detection unit or the azimuth angle, the elevation angle, or the polarization angle driven by the drive unit makes a change from an initial setting value to a predetermined threshold value or more, and a stop processing unit that stops transmission of the radio wave from the antenna when the determination unit determines that the change from the initial setting value to the predetermined threshold value or more is made.

Abstract: Determination information necessary to determine accuracy of detection of a longitude, a latitude, and an altitude of an antenna is acquired, whether the accuracy of detection of the longitude, the latitude, and the altitude is in a necessary and sufficient level is determined in accordance with the acquired determination information, the longitude, the latitude, the altitude, the azimuth, and the inclination of the antenna are detected also after elapse of a predetermined time after the transmission of the radio wave from the antenna is stopped, and the antenna is driven to adjust the azimuth angle, the elevation angle, and the polarization angle of the antenna to the communication satellite in accordance with the longitude, the latitude, the altitude, the azimuth, and the inclination of the antenna detected after elapse of the predetermined time after the transmission of the radio wave from the antenna is stopped.