| 摘要 |
PROBLEM TO BE SOLVED: To provide a technology that reliably updates a distributed program to a large number of terminals by utilizing an artificial satellite. SOLUTION: Each terminal 12 to which an update program has been distributed informs a host 10 via a ground channel about a reception failure or reception completion in response to the result of reception, updates a program when the reception of the update program is completed, informs the host 10 of the update failure or update completion depending on an update result. The host 10 receiving the notice stores the processing status of each terminal 12, executes processing corresponding to the processing status, identifies a terminal whose update is not finished after the lapse of a prescribed time after the distribution of the update program, judges a terminal giving no reply as that receiving no message and executes again a corresponding processing to the processing state for the terminal. |
