Communication apparatus, communication control method, and communication control program

A communication control method that controls communication on a communication path to which a plurality of vehicle-mounted apparatuses are connected, the communication method comprising:

• a step of determining whether a transmission timing of a first frame, out of a scheduled plurality of frames to be transmitted on the communication path, exceeds a first delay time;
• a step of estimating, when it has been determined that the transmission timing of the first frame exceeds the first delay time, a transmission timing of a second frame whose transmission timing changes due to a change in a transmission order of the first frame;
• a step of determining whether the estimated transmission timing of the second frame exceeds a second delay time;
• a step of generating, when it has been determined by the determination unit that the transmission timing of the second frame exceeds the second delay time, a stop request frame for requesting a stopping of transmission of different frames aside from the first frame and the second frame until the first frame and the second frame have been transmitted on the communication path;
• and
• a step of transmitting the generated stop request frame via the communication path to the plurality of vehicle-mounted apparatuses.

A communication control program for controlling communication on a communication path to which a plurality of vehicle-mounted apparatuses are connected,

• the communication control program causing a computer to execute a process comprising:
• a step of determining whether a transmission timing of a first frame, out of a scheduled plurality of frames to be transmitted on the communication path, exceeds a first delay time;
• a step of estimating, when it has been determined that the transmission timing of the first frame exceeds the first delay time, a transmission timing of a second frame whose transmission timing changes due to a change in a transmission order of the first frame;
• a step of determining whether the estimated transmission timing of the second frame exceeds a second delay time;
• a step of generating, when it has been determined by the determination unit that the transmission timing of the second frame exceeds the second delay time, a stop request frame for requesting a stopping of transmission of different frames aside from the first frame and the second frame until the first frame and the second frame have been transmitted on the communication path;
• and
• a step of transmitting the generated stop request frame via the communication path to the plurality of vehicle-mounted apparatuses.