Wireless communication system, communication apparatus, wireless communication method and communication program

A wireless communication system in which a relay apparatus provided in a mobile object wirelessly communicates with a plurality of communication apparatuses placed at different locations,

• wherein the relay apparatus comprising:
• a processor;
• and
• a storage medium having computer program instructions stored thereon, wherein the computer program instructions, when executed by the processor, perform to:
• receive a plurality of signals transmitted from the plurality of communication apparatuses and including position information indicating positions of the plurality of communication apparatuses;
• measure a congestion level of communication in the receiving;
• divide a communication target area into a plurality of small areas in accordance with the positions of the plurality of communication apparatuses and the congestion level of communication, and generate area information indicating positions of the plurality of small areas;
• and
• sequentially transmit a plurality of pieces of the area information when the relay apparatus is positioned in a range in which the relay apparatus can communicate with the plurality of communication apparatuses, and
• each of the plurality of communication apparatuses comprising:
• a processor;
• and
• a storage medium having computer program instructions stored thereon, wherein the computer program instructions, when executed by the processor, perform to:
• store transmission data to be transmitted to the relay apparatus;
• receive the area information;
• determine whether a position of the communication apparatus is included in the plurality of small areas indicated in the area information;
• and
• transmit a signal including the transmission data and position information indicating a position of the communication apparatus to the relay apparatus in a case in which the position of the communication apparatus is included in the plurality of small areas.