| 摘要 |
PURPOSE:To prevent duplicated reception of data block, by abolishing a retransmission block due to misreception of other reception earth station, taking into a chance a retransmission start informing block, at a reception earth station. CONSTITUTION:A transmission earth station transmits the message of the same content to a plurality of reception earth stations (a), (b) continuously at the same time in the unit of data block of a fixed length. Further, the stations (a), (b) detects the presence of transmission error to received data block and returns the results A, N to a transmission earth station. When the transmission earth station receives the response N of misreception, a retransmission start informing block R is transmitted and succeedingly, the data block is retransmitted by retroacting by a fixed number. In the station (a), the blocks from a transmission error block 1 to the block R are abolished. At the same time, in the station (b), blocks from the block R to retransmitted data blocks 1-3 are abolished. |
