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.

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 sent a call packet to call another at least one communication terminal, a communication session in which this communication terminal that has made a call and a communication terminal that has been called are participating terminals is established. In the communication session, voice communication is relayed by transferring a voice signal which is transmitted from the participating terminals to another at least one communication terminal. A virtual device is registered as a participating terminal of the communication session and the voice signal which is transmitted from the communication session to the virtual device is recorded in the relaying device.

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.