Abstract: [Problem] To provide an audio communication system in which a relaying device is connected to communication devices via a communication network, the communication devices being terminal devices, and the current location of each terminal device is managed by the relaying device. [Solution] this relaying device is provided with a network communication unit, a control unit, and a storage unit. The control unit divides the communication area of a communication network into a plurality of partial communication areas and stores, in the storage unit, location information indicating which partial communication area each terminal device is in.

Abstract: An electronic device including a submersion detector, an illuminant provided inside a casing, a lighting circuit, a controller, an unnecessary part that is unnecessary for lighting the illuminant. The submersion detector detects submersion of the electronic device and retrieval of the device. The submersion means that the electronic device falls onto or into water. The retrieval means that the electronic device is retrieved from water. The lighting circuit lights the illuminant in response to an input of a lighting signal. The controller lights the illuminant by generating and outputting the lighting signal to the lighting circuit for a period of time from the submersion at least until the retrieval. In a case where the unnecessary part is supplied with power when the submersion detector detects the submersion, the controller stops the supply of the power to the unnecessary part at least for the above period of time.

Abstract: A data calculator repeatedly calculates electric power of a delayed transmission signal and a multiplication value of a complex conjugate of the delayed transmission signal and a feedback signal. A memory stores, for each delayed electric power address corresponding to the electric power, a first total value that is the total of electric power of the delayed transmission signal and a second total value that is the total of the multiplication value. A range adjuster adjusts the upper limit of a determination reference range according to the maximum reference address. When a determiner determines that the number of repeats of the data calculator is sufficient based on the determination reference range, a vector calculator calculates a distortion correction vector based on a distortion vector calculated from the ratio between the first total value and the second total value. An updater updates the distortion correction vector stored in a look-up table based on the distortion correction vector.

Abstract: A radio apparatus includes a Man-Overboard detection unit, a control unit and a distress key. The Man-Overboard detection unit outputs a Man-Overboard signal when the radio apparatus has fallen to a water surface or into water. The control unit generates a distress signal including a distress type. A distress key outputs a distress key manipulation signal to the control unit when the distress key is manipulated. When the control unit receives the Man-Overboard signal from the Man-Overboard detection unit, the control unit automatically sets a distress type of the distress signal to Man-Overboard.

Abstract: [Problem] To enable group communication with a high degree of freedom in a voice communication system in which a relay device and a terminal device are connected over a communication network. [Solution] A voice communication system comprises a terminal device and a relay device which transmit and receive a voice signal with each other over a network. The relay device has a group table. The terminal device transmits, to the relay device, specifying information specifying a group to which the terminal device belongs. When receiving the specifying information from the terminal device, the relay device registers the terminal device in the group table, so as to belong to the designated group. The terminal device transmits, to the relay device, a voice signal destined to the group to which the terminal device belongs. When receiving, from the terminal device, the voice signal destined to the belonging group, the relay device transfers the voice signal to another terminal device belonging to the specified group.

Abstract: [Problem] To provide a voice communication system which causes a relaying device to manage communication between terminal devices based on the affiliations of the terminal devices, and manage the current positions of the respective terminal devices. [Solution] In a voice communication system, a relaying device relays voice communication of a plurality of section systems. The relaying device stores, with respect to each of the section systems, a plurality of pieces of area information divided on the basis of the communication range of a wireless access point. A terminal device transmits a voice signal to which the identification code thereof is added. When receiving the voice signal from the terminal device, the relaying device identifies a section system to which this terminal device belongs from the identification code added to the voice signal, and identifies an area in which the terminal device is present on the basis of positional information relating to the terminal device.

Abstract: A radio apparatus in which voice frames can be used for data transmission, which prevents abnormal sound and noise from occurring during fast data transmission. A controller of the radio apparatus determines whether the voice frames are being used for voice signal transmission or data transmission based on a result of identification of a mini-header that is stored in the data frames. The controller causes a voice signal reproduction unit to perform a muting operation when a result of the determination successively indicates that the voice frames are being used for data transmission a predetermined first number of times, and the controller causes the voice signal reproduction unit to cancel the muting operation when the result of the determination successively indicates that the voice frames are being used for voice signal transmission a predetermined second number of times in a situation where the muting operation is being performed.

Abstract: [Problem] To provide an audio communication system in which a relaying device is connected to terminal devices via a communication network and said terminal devices communicate with each other on the basis of assignments for said terminal devices. [Solution] This relaying device is provided with a network communication unit, a storage unit, and a control unit. The network communication unit is connected to a communication network and communicates with a plurality of terminal devices over said communication network. The storage device assigns each terminal device to one of a plurality of subsystems and stores, for each terminal device, the assigned subsystem and identifying information. When an audio signal is received from a given terminal device, the control unit identifies the subsystem to which said terminal device is assigned from originating-terminal-device information attached to the audio signal and forwards the audio signal to another terminal device assigned to the identified subsystem.

Abstract: When operating the radio communication system in a mode for transmitting data for data communication instead of audio signal data, a transmission unit of a radio apparatus generates a packet in which data for data communication is inserted in positions in an audio frame, except for a given position, and in a data frame, and unique data is inserted in the given position in the audio frame. Also, data that is likely to cause an error when the data inserted in the audio frame is decoded by using an audio codec is used as the unique data.

Abstract: A transmission unit of a radio apparatus generates a packet including: a header part containing identifier data identifying at least a transmission destination radio station and a transmission source radio station; and a data part in which an audio frame and a data frame, each having a predetermined length, are consecutively arranged one after another. When communication is performed in a fast data mode in which data for data communication to be transmitted, instead of a digital audio signal, is inserted in the audio frame, the transmission unit generates, according to an instruction from the controller, a packet in which data for data communication is inserted in the audio frame and the data frame, and the transmission unit converts the packet into a radio signal and transmits the radio signal.

Abstract: An electronic device including a submersion detector, illuminants, a lighting circuit, a controller, and an orientation detector. The submersion detector detects submersion of the device and detect retrieval of the device. The illuminants are arranged inside a casing such that at least one of the illuminants is visible from above water when the device is submerged in any submersion orientation. The lighting circuit lights up at least one of the illuminants in response to an input of a lighting signal. The controller generates and outputs the lighting signal to the lighting circuit for a period of time from the submersion at least until the retrieval so as to light up the at least one of the illuminants. The orientation detector detects a submersion orientation of the device. Only the at least one of the illuminants that is visible from above water lights up, in accordance with the detected submersion orientation.

Abstract: In a radio apparatus that can simultaneously perform audio communication and data communication, the amount of data for data communication that can be transmitted during a single call is increased, and the communication speed of data communication is thereby increased. A transmission unit generates a packet in which an audio frame and a data frame, are consecutively arranged one after another. When receiving a transmission start command from a controller the transmission unit generates a packet in which data of an audio signal is inserted in the audio frame and data for data communication is inserted in the data frame, and when receiving a mode change command from the controller, the transmission unit generates and transmits, during a fixed time period from reception of the command, a packet in which data for data communication is inserted in the audio frame and the data frame.

Abstract: A radio apparatus includes a control unit, a power unit, a distress key and a transmission unit. When the distress key is manipulated, a distress key manipulation signal is output to the control unit and the power unit. When the power unit receives the distress key manipulation signal during a power supply is stopped, the power unit supplies power to the control unit and the transmission unit. When the control unit receives power from the power unit, the control unit starts setting up the radio apparatus and counts a time that the control unit continuously receives the distress key manipulation signal. When the control unit continuously receives the distress key manipulation signal for a preset time or longer, the control unit outputs a power supply maintenance signal to the power unit, generates the distress signal, and causes the transmission unit to send the distress signal.

Abstract: A relaying device includes a wireless apparatus interface, a signal processing unit connected to the wireless apparatus interface, a network interface, and a packet processing unit connected to the network interface. The relaying device is provided with multiple communication paths including the wireless apparatus interface, the signal processing unit, and the packet processing unit, and each communication path has a mixing unit configured to additively synthesize an uplink audio signal and a downlink audio signal of other communication path to the uplink audio signal and input the synthesized signal to the packet processing unit, and configured to additively synthesize an uplink audio signal and a downlink audio signal of other communication path to the downlink audio signal and input the synthesized signal to the signal processing unit.