Abstract: A communication system includes a transmission terminal and a reception terminal. One of the transmission terminal and the reception terminal includes a processor. The processor is configured to calculate an adjustment value indicating a difference between an imaging cycle and a display cycle. The processor is configured to cause the imaging cycle and the display cycle to match each other by adjusting a signal generator on the basis of the adjustment value. A connection history in which adjustment information and identification information of a communicator are associated with each other is recorded on a recording medium. The processor is configured to adjust the signal generator on the basis of the adjustment value indicated by the adjustment information when the first communicator and the second communicator connect to each other again.

Abstract: A reception device includes a wireless communicator, a memory, and one or more processors. The processors identify a retransmission candidate of image data on the basis of a sequence number recorded on the memory. The processors calculate an upper limit retransmission number on the basis of a physical rate and a communication rate recorded on the memory. The processors set an allowable retransmission number that is less than or equal to the upper limit retransmission number. The processors transmit a retransmission request for requesting retransmission of as many of the retransmission candidates as the allowable retransmission number to the transmission device in a blanking period by using the wireless communicator when the number of the retransmission candidates identified through the identification processing exceeds the allowable retransmission number.

Abstract: In a wireless communication terminal, a control circuit is configured to cause a wireless communicator to wirelessly connect to a first AP on the basis of authentication information of the first AP stored on a memory and is configured to execute authentication processing with the first AP on the basis of the authentication information of the first AP stored on the memory without executing setup processing when the control circuit selects a first mode. The control circuit is configured to start the setup processing with a second AP by using the wireless communicator when the control circuit selects the second mode. The control circuit is configured to cause the wireless communicator to wirelessly connect to the second AP and is configured to execute the authentication processing with the second AP on the basis of authentication information received from the second AP by the wireless communicator.

Abstract: A reception device includes a wireless communicator, a memory, and one or more processors. The processors identify a retransmission candidate of image data on the basis of a sequence number recorded on the memory. The processors calculate an upper limit retransmission number on the basis of a physical rate and a communication rate recorded on the memory. The processors set an allowable retransmission number that is less than or equal to the upper limit retransmission number. The processors transmit a retransmission request for requesting retransmission of as many of the retransmission candidates as the allowable retransmission number to the transmission device in a blanking period by using the wireless communicator when the number of the retransmission candidates identified through the identification processing exceeds the allowable retransmission number.

Abstract: A first communicator of a first communication device is configured to use a first wireless channel and execute first key-exchange processing at a timing at which a first key-exchange timer expires. A second communicator of the first communication device is configured to use a second wireless channel and execute second key-exchange processing at a timing at which a second key-exchange timer expires. When streaming data are transmitted by using one wireless channel of the first wireless channel and the second wireless channel and a difference between a first key-exchange timer value and a second key-exchange timer value is greater than a predetermined range, a control circuit is configured to change a wireless channel used for transmission to the other wireless channel before key-exchange processing in the one wireless channel is started.

Abstract: A comnunication system includes a transmission terminal and a reception terminal. One of the transmission terminal and the reception terminal includes a processor. The processor is configured to calculate an adjustment value indicating a difference between an imaging cycle and a display cycle. The processor is configured to cause the imaging cycle and the display cycle to match each other by adjusting a signal generator on the basis of the adjustment value. A connection history in which adjustment information and identification information of a communicator are associated with each other is recorded on a recording medium. The processor is configured to adjust the signal generator on the basis of the adjustment value indicated by the adjustment information when the first communicator and the second communicator connect to each other again.

Abstract: An image transfer system including an imaging terminal and a display terminal. A processor included in one terminal of the imaging terminal and the display terminal is programmed to execute a communication delay time calculation function of generating a first measurement signal in synchronization with the imaging period and transmitting the first measurement signal to the other terminal, receiving a second measurement signal in accordance with the first measurement signal transmitted from the other terminal, and calculating a communication delay time according to a transmission timing of the first measurement signal, a reception timing of the second measurement signal, and elapsed time data included in the second measurement signal and indicating an elapsed time from a reception timing of the first measurement signal to a transmission timing of the second measurement signal in the other terminal.

Abstract: An image transmission system, has an imaging terminal configured to transmit image data at a cycle of imaging timing; and a display terminal configured to receive the image data and display the image data at a cycle of display timing. The image transmission system has functions of calculating communication delay time, estimating accuracy after adjusting a cycle of the imaging timing or the display timing, determining whether to perform an adjustment of the imaging timing or the display timing, and performing the adjustment of the imaging timing or the display timing which are included in either of the imaging terminal or the display terminal. The image transmission system further has a function of assisting the calculation of the communication delay time which is included in the other of the imaging terminal or the display terminal.

Abstract: In a wireless communication terminal, a control circuit is configured to cause a wireless communicator to wirelessly connect to a first AP on the basis of authentication information of the first AP stored on a memory and is configured to execute authentication processing with the first AP on the basis of the authentication information of the first AP stored on the memory without executing setup processing when the control circuit selects a first mode. The control circuit is configured to start the setup processing with a second AP by using the wireless communicator when the control circuit selects the second mode. The control circuit is configured to cause the wireless communicator to wirelessly connect to the second AP and is configured to execute the authentication processing with the second AP on the basis of authentication information received from the second AP by the wireless communicator.

Abstract: A first communicator of a first communication device is configured to use a first wireless channel and execute first key-exchange processing at a timing at which a first key-exchange timer expires. A second communicator of the first communication device is configured to use a second wireless channel and execute second key-exchange processing at a timing at which a second key-exchange timer expires. When streaming data are transmitted by using one wireless channel of the first wireless channel and the second wireless channel and a difference between a first key-exchange timer value and a second key-exchange timer value is greater than a predetermined range, a control circuit is configured to change a wireless channel used for transmission to the other wireless channel before key-exchange processing in the one wireless channel is started.

Abstract: In a wireless communication terminal, a controller wirelessly receives communication channel information from a first terminal by using a communicator. The communication channel information transmitted from the first terminal to the wireless communication terminal includes first information and second information. The communication channel information transmitted from the second terminal to the first terminal includes the second information. The first information represents a communication channel used for wireless communication by the first terminal. The second information represents a communication channel used for wireless communication by the second terminal. The controller determines a communication channel used for wireless communication by the wireless communication terminal on the basis of the communication channel information.

Abstract: An image transfer system including an imaging terminal and a display terminal. A processor included in one terminal of the imaging terminal and the display terminal is programmed to execute a communication delay time calculation function of generating a first measurement signal in synchronization with the imaging period and transmitting the first measurement signal to the other terminal, receiving a second measurement signal in accordance with the first measurement signal transmitted from the other terminal, and calculating a communication delay time according to a transmission timing of the first measurement signal, a reception timing of the second measurement signal, and elapsed time data included in the second measurement signal and indicating an elapsed time from a reception timing of the first measurement signal to a transmission timing of the second measurement signal in the other terminal.

Abstract: An image transmission system, has an imaging terminal configured to transmit image data at a cycle of imaging timing; and a display terminal configured to receive the image data and display the image data at a cycle of display timing. The image transmission system has functions of calculating communication delay time, estimating accuracy after adjusting a cycle of the imaging timing or the display timing, determining whether to perform an adjustment of the imaging timing or the display timing, and performing the adjustment of the imaging timing or the display timing which are included in either of the imaging terminal or the display terminal. The image transmission system further has a function of assisting the calculation of the communication delay time which is included in the other of the imaging terminal or the display terminal.

Abstract: A controller of a wireless communication terminal wirelessly receives second communication channel information from a second wireless communication terminal using a communicator. The controller wirelessly transmits first communication channel information and the second communication channel information to a third wireless communication terminal using the communicator. The controller wirelessly receives third communication channel information from the third wireless communication terminal using the communicator. The controller wirelessly transmits the first communication channel information and the third communication channel information to the second wireless communication terminal using the communicator.

Abstract: A synchronization signal generation function of an image transmitter is configured to generate an imaging synchronization signal. One or more processors of the image transmitter cause an imager of the image transmitter to perform new imaging every time the imaging synchronization signal is generated and cause communication data corresponding to captured image data output from the imager to be transmitted from a communicator of the image transmitter to an image receiver by radio waves. A synchronization signal generation function of the image receiver is configured to generate a display synchronization signal. One or more processors of the image receiver is configured to generate a display image corresponding to the captured image data from the communication data received by radio waves in a communicator of the image receiver and cause a monitor of the image receiver to display a newly generated display image every time the display synchronization signal is generated.

Abstract: A wireless communication terminal has a plurality of communicators, a radar detection circuit, a channel use confirmation circuit, a channel information acquisition circuit, a channel information notification circuit, a channel determination circuit, and a channel setting circuit. First communication channel information indicates a data communication channel set in a communicator of a first peripheral terminal. Second communication channel information indicates a monitoring communication channel set in the communicator of the first peripheral terminal or a communication channel confirmed to be usable by the channel use confirmation circuit of the first peripheral terminal. The channel determination circuit determines a communication channel different from any of a first communication channel indicated by the first communication channel information and a second communication channel indicated by the second communication channel information as the data communication channel.

Abstract: A wireless communication terminal has a plurality of communicators, a radar detection circuit, a channel use confirmation circuit, a channel information acquisition circuit, a channel information notification circuit, a channel determination circuit, and a channel setting circuit. First communication channel information indicates a data communication channel set in a communicator of a first peripheral terminal. Second communication channel information indicates a monitoring communication channel set in the communicator of the first peripheral terminal or a communication channel confirmed to be usable by the channel use confirmation circuit of the first peripheral terminal. The channel determination circuit determines a communication channel different from any of a first communication channel indicated by the first communication channel information and a second communication channel indicated by the second communication channel information as the data communication channel.

Abstract: In a wireless communication terminal, a controller wirelessly receives communication channel information from a first terminal by using a communicator. The communication channel information transmitted from the first terminal to the wireless communication terminal includes first information and second information. The communication channel information transmitted from the second terminal to the first terminal includes the second information. The first information represents a communication channel used for wireless communication by the first terminal. The second information represents a communication channel used for wireless communication by the second terminal. The controller determines a communication channel used for wireless communication by the wireless communication terminal on the basis of the communication channel information.

Abstract: A controller of a wireless communication terminal wirelessly receives second communication channel information from a second wireless communication terminal using a communicator. The controller wirelessly transmits first communication channel information and the second communication channel information to a third wireless communication terminal using the communicator. The controller wirelessly receives third communication channel information from the third wireless communication terminal using the communicator. The controller wirelessly transmits the first communication channel information and the third communication channel information to the second wireless communication terminal using the communicator.

Abstract: A synchronization signal generation function of an image transmitter is configured to generate an imaging synchronization signal. One or more processors of the image transmitter cause an imager of the image transmitter to perform new imaging every time the imaging synchronization signal is generated and cause communication data corresponding to captured image data output from the imager to be transmitted from a communicator of the image transmitter to an image receiver by radio waves. A synchronization signal generation function of the image receiver is configured to generate a display synchronization signal. One or more processors of the image receiver is configured to generate a display image corresponding to the captured image data from the communication data received by radio waves in a communicator of the image receiver and cause a monitor of the image receiver to display a newly generated display image every time the display synchronization signal is generated.