| 摘要 |
PURPOSE:To improve the line efficiency of a satellite communication line by instructing a master station to perform a retransmission from a center based on the error result of a block unit of reception data of each slave station when a multi-address communication is performed from the master station to a slave station via the satellite communication line. CONSTITUTION:A multi-address communication from a master station 20 to slave stations 30, 40 is performed via a satellite communication line 102 and the salve stations 30, 40 transmits the result of an error check by a block unit to a center 10 via a ground line 103. The center 10 instructs the master station 20 to perform a retransmission via a ground line 101 based on the result of the error check. The master station 20 performs the retransmission to the slave stations 30, 40 from the master station 20 via the line 102 when there are a numbers of error blocks. The station 20 performs the retransmission to the slave stations 30, 40 from the center 10 via the line 103 when there are few numbers of the error blocks. Thus, the number of the satellite communication line can be reduced and line cost is reduced. |
