Repeater

A repeater in a vehicle communication system for retransmitting a communication frame between a plurality of communication nodes, the repeater comprising:

• a storage unit configured to store a routing map that associates (i) a frame ID of the communication frame for identifying the communication frame received from one of the plurality of communication nodes with (ii) a transmission destination of the communication frame;
• a retransmission unit configured to retransmit the communication frame between the plurality of communication nodes based on the routing map stored in the storage unit;
• a determiner configured to determine whether a preset condition for generating the routing map is satisfied;
• and
• a generator configured to generate and store the routing map in the storage unit based on information in the communication frame received from the one of the plurality of communication nodes, when the determiner determines that the preset condition for generating the routing map is satisfied.