| 摘要 |
PURPOSE:To retransmit data blocks, after retransmission start informing blocks are transmitted, by stopping the continuous transmission of the data blocks from a transmission earth station, when the number of response of normal reception confirmation from a plurality of reception earth stations is less than the predetermined number. CONSTITUTION:When a transmitter 11 recieves a response from a plurality of reception stations via a line 12, the types of response is discriminated at a specific block generation detection section (BGD)22 and the number of responses A for normal reception confirmation is informed to a data block reception success discriminating section (ACT)24. The ACT24 receiving the information compares the number of responses of normal reception confirmation with the number of reception guarantee earth stations, and when the former is less than the latter, the retransmission request is informed to a transmission control section (DTC)15. The DTC15 receiving the information of the retransmission request abolishes the data block of a data block buffer (DBM)19 and requests for retransmission of data block to a terminal via a line 13. The DTC15 requests for transmission of a retransmission start informing block R to a BGD22 and transmits the R via the line 12. |
