| 摘要 |
PROBLEM TO BE SOLVED: To speedily and surely give a notice to an on-vehicle terminal by a communication system which distributes a program from a central station by radio communication, etc., when the program is revised. SOLUTION: When a program is revised at a central station 10, a line of two-way communication is connected, and revision information is sent to an on-vehicle terminal 30. The revision information is reported by a dedicated message or dedicated protocol. Furthermore, the central station 10 is able to e-mail the notice to the on-vehicle terminal. Additionally, the notice of the revision may be sent also to the on-vehicle terminal 30 by unidirectional broadcasting.
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