COMMUNICATION METHOD AND COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a communication system capable of maintaining precise timing of communication when the GPS is not capable of stable reception for a long period.SOLUTION: A communication method includes a step for applying a time of an on-vehicle apparatus 11 when the quality of a signal of the GPS 20 is at a predetermined level or lower than the level or when the on-vehicle apparatus 11 exists at a precision deterioration position of a data base 18 of GPS time precision deterioration places.