Reception device, communication system, and recording medium

A communication system, comprising:

• a transmission device;
• and
• a reception device,
• wherein the transmission device comprises:
• a first memory on which image data are temporarily recorded;
• a first wireless communicator configured to transmit the image data including a sequence number to the reception device and receive a retransmission request for requesting retransmission of the image data from the reception device;
• and
• one or more first processors configured to execute retransmission processing of transmitting the image data requested by using the retransmission request to the reception device by using the first wireless communicator when the first wireless communicator receives the retransmission request from the reception device, and
• wherein the reception device comprises:
• a second wireless communicator configured to receive the image data from the transmission device;
• a second memory on which a physical rate of the second wireless communicator and a communication rate of the image data are recorded;
• and
• one or more second processors configured to execute:
• recording processing of recording the sequence number of the image data received by the second wireless communicator on the second memory;
• image output processing of outputting the image data received by the second wireless communicator to a monitor;
• identification processing of identifying a retransmission candidate on the basis of the sequence number recorded on the second memory,
• wherein the retransmission candidate indicates image data that have been transmitted by the transmission device and have not been received by the second wireless communicator;
• calculation processing of calculating an upper limit retransmission number on the basis of the physical rate and the communication rate recorded on the second memory,
• wherein the upper limit retransmission number indicates an upper limit of the number of pieces of image data of which retransmission has been requested;
• setting processing of setting an allowable retransmission number that is less than or equal to the upper limit retransmission number;
• and
• retransmission request processing of transmitting a retransmission request for requesting retransmission of as many of the retransmission candidates as the allowable retransmission number to the transmission device by using the second wireless communicator when the number of the retransmission candidates identified through the identification processing exceeds the allowable retransmission number,
• wherein the one or more second processors are configured to execute the retransmission request processing in a blanking period,
• wherein the blanking period is a period from a first timing to a second timing,
• wherein the first timing comes after transmission of N-th frame data including one or more pieces of image data for the first time is completed,
• wherein the second timing comes after the first timing and before transmission of (N+1)-th frame data including one or more pieces of image data for the first time is started,
• wherein N is an integer of one or more,
• wherein the one or more second processors are configured to execute the retransmission request processing in the blanking period after transmission of K-th frame data including one or more pieces of image data for the first time is completed so as to transmit the retransmission request of M-th frame data including one or more pieces of image data to the transmission device, and
• wherein M is an integer of one or more and K is an integer that is greater than or equal to (M+1).

A non-transitory computer-readable recording medium storing a program causing one or more processors of a reception device including a wireless communicator configured to receive image data that are transmitted by a transmission device and include a sequence number, a memory on which a physical rate of the wireless communicator and a communication rate of the image data are recorded, and the one or more processors to execute:

• recording processing of recording the sequence number of the image data received by the wireless communicator on the memory;
• image output processing of outputting the image data received by the wireless communicator to a monitor;
• identification processing of identifying a retransmission candidate on the basis of the sequence number recorded on the memory,
• wherein the retransmission candidate indicates image data that have been transmitted by the transmission device and have not been received by the wireless communicator;
• calculation processing of calculating an upper limit retransmission number on the basis of the physical rate and the communication rate recorded on the memory,
• wherein the upper limit retransmission number indicates an upper limit of the number of pieces of image data of which retransmission has been requested;
• setting processing of setting an allowable retransmission number that is less than or equal to the upper limit retransmission number;
• and
• retransmission request processing of transmitting a retransmission request for requesting retransmission of as many of the retransmission candidates as the allowable retransmission number to the transmission device by using the wireless communicator when the number of the retransmission candidates identified through the identification processing exceeds the allowable retransmission number,
• wherein the one or more processors execute the retransmission request processing in a blanking period,
• wherein the blanking period is a period from a first timing to a second timing,
• wherein the first timing comes after transmission of N-th frame data including one or more pieces of image data for the first time is completed,
• wherein the second timing comes after the first timing and before transmission of (N+1)-th frame data including one or more pieces of image data for the first time is started,
• wherein N is an integer of one or more,
• wherein the one or more processors execute the retransmission request processing in the blanking period after transmission of K-th frame data including one or more pieces of image data for the first time is completed so as to transmit the retransmission request of M-th frame data including one or more pieces of image data to the transmission device, and
• wherein M is an integer of one or more and K is an integer that is greater than or equal to (M+1).