Abstract: A frequency selector included in a radio station selects a target frequency for carrier sensing from within a bandwidth of one of a plurality of subcarriers for a channel specified for wireless communication in accordance with Orthogonal Frequency Division Multiplexing, at least a portion of the bandwidth of the one of the subcarriers being within a transmission band. A detector detects a signal level, at the target frequency, of a real signal obtained as a result of digitally converting an electric signal derived from a radio wave captured by an antenna. A determiner determines whether the transmission band is used for the wireless communication from the signal level.

Abstract: A detector included in a radio station detects a signal level, at a designated transmission frequency, of a real signal obtained as a result of digitally converting an electric signal derived from a radio wave captured by an antenna by applying a time window specified according to a length of time of a beacon used in wireless communication to the real signal. A determiner determines whether a transmission band containing the transmission frequency is used for the wireless communication from the detected signal level.

Abstract: There is provided a relay apparatus that enables a communication voice of a specific communication terminal to be tracked and recorded. A call from a communication terminal results in establishment of a communication session in which the calling communication terminal and a called communication terminal are regarded as participating terminals. Transmission of a voice signal from any of the participating terminals in the established communication session allows the voice signal to be transmitted, together with session information, to the other participating terminal in the same communication session. A virtual device is associated with the communication terminal, and the communication terminal and the virtual device establish a virtual communication session. In the virtual communication session, the voice signal transmitted from the communication session to the virtual device is recorded in a communication monitor.

Abstract: In a wireless device that can easily change a volume depending on whether a hands-free call function of the wireless device is on or off. The wireless device provided with a volume knob that changes the volume value according to the rotation angle of the knob, a volume change key that changes the volume value by pressing the key, and a hands-free call function on/off switching key that turns the hands-free call function on and off, and a controller for controlling the wireless device. The controller monitors whether the hands-free call function is on or off, and when the hands-free call function is on, the volume can be changed by operating the volume knob, and when the hands-free call function is off, the volume can be changed by operating the volume change key.

Abstract: A server system including a plurality of servers achieves redundancy on a per process basis. A first server and a second server execute a plurality of processes in parallel. Processes (B1-1, B2-1, and Br-1) in the first server are active processes, and processes (B1-2, B2-2, and Br-2) in the second server are standby processes. The active process periodically transmits an operation notification notifying normal operation, to the standby process. When no longer receiving an operation notification from the active process, the standby process switches an operation mode of the standby process from a standby mode to an active mode and starts provision of service of the process. The process switching is performed on a per process basis instead of on a per server basis.

Abstract: A gateway device (30) relays voice communication between a communication terminal to be connected to a closed network (10) and a communication terminal to be connected to a LAN (20). The gateway device (30) includes a closed network communicator (31) connected to the closed network (10), a communication relay (32) to perform encapsulation or decapsulation of data for enabling voice communication between the closed network (10) and the LAN (20), and a LAN communicator (33) connected to the LAN (20).

Abstract: Provided is a voice communication system that notifies a terminal device of transmission restriction information when the number of received voice signals reaches a predetermined number. A server device continuously counts the number of simultaneously received voice signals. A first terminal device transmits, to the server device, a voice signal with identification information of a second terminal device. The server device transfers, to the second terminal device, the voice signal transmitted from the first terminal device. However, when the number of simultaneous receptions of the voice signals reaches a predetermined restriction value, the server device transfers, to the second terminal device, the received voice signal with transmission restriction information attached thereto. The second terminal device does not transmit a voice signal, even if a user performs a transmission operation, during reception of the voice signal with the attached transmission restriction information.

Abstract: A wireless system includes a control device and a wireless communication device. The control device switches between a control-side access point mode and a control-side station mode. In the control-side access point mode, the control device receives a connection request from the wireless communication device to establish a connection and, in the control-side station mode sends a connection request to the wireless communication device to establish a connection. The control device sends a sleep command or a wake-up command to the wireless communication device with which the connection is established.

Abstract: Provided is a server system robust against a communication path failure. A first server system 2-1 and a second server system 2-2 are respectively installed on a first network 3-1 and a second network 3-2 provided by common carriers different from each other. The first and second server systems are connected to each other by a dedicated line 6. Even when a failure occurs in the first network, communication through the second network can be maintained, and even when a failure occurs in the second network, communication through the first network can be maintained. Further, when a failure occurs in the dedicated line, operations can be performed within each of the first and second networks in a degeneracy mode.

Abstract: A communication device that reduces power consumption is realized by appropriately setting a transmission output power value for DSC communication. A communication device (1) includes: an AIS receiving section (11) for receiving information related to an AIS; a DSC communication section (12) for performing DSC communication; and a transmission output power setting section (15c) configured to set a transmission output power value for communication performed on a conversation channel by the DSC communication section to a value corresponding to a distance, which is calculated based on the information, between the communication device and a communication target vessel.

Abstract: A communication device includes: a display section; an AIS receiving section configured to receive automatic identification system (AIS) information; a list creating section configured to create, based on the AIS information about vessels existing in the vicinity of the communication device, a proximity order list in which pieces of specific information for identifying the vessels are arranged in increasing order of proximity to the communication device; and a display control section configured to, when the submersion of the communication device has been detected, control the display section so that the display section displays the proximity order list and so that any one of the pieces of specific information at the top of the proximity order list is in a selected state.

Abstract: [Problem] When a communication apparatus that is the communication partner is called via a relay device, the transmission control mode of a voice signal can be switched according to the capability of the communication partner. [Solution] A relay device (2) includes a telephone relay unit (3), a network communication relay unit (4), and a wireless communication relay unit (5). The wireless communication relay unit (5) includes a plurality of external apparatus interfaces, and an analog repeater (25), a digital repeater (27), or the like is connected to each external apparatus interface. If an SIP telephone (20) has called an analog transceiver (27), the relay device (2) obtains the address and apparatus type of the analog transceiver (27) from call information, and transmits a voice signal to the analog transceiver (27) using a transmission control mode (VOX mode) that suits the analog transceiver (27).

Abstract: [Problem] Provided is a relaying device that can track and record a communicated voice of a specific communication terminal using a mixing function of the relaying device. [Solution] When a communication terminal has made a call, a communication session in which the communication terminal that has made a call and a communication terminal that has been called are participating terminals is established. When a voice signal is transmitted from one participating terminal of the established communication session, this voice signal is transmitted to the other participating terminal(s) of the same communication session along with session information. A virtual device is associated with a communication terminal, and is registered in a communication session in which the communication terminal participates as a participating terminal together with the communication terminal. A communication monitoring unit records a voice signal transmitted to the virtual device from the communication session.

Abstract: A wireless station includes at least one oscillator to output a reference signal, and an error calculator to calculate a frequency of the reference signal and calculate a frequency error by subtracting a target frequency of the reference signal from the calculated frequency of the reference signal. The wireless station further includes a modulation data generator to generate modulation data by adding a correction value, varying in negative correlation with the frequency error calculated by the error calculator, to data to be transmitted, and a modulator to conduct frequency modulation on the basis of the modulation data and the reference signal.