| 摘要 |
PROBLEM TO BE SOLVED: To provide the communication system where a reception station can surely recognize as to what files are sent by multiple-address communication and a satellite channel is effectively utilized. SOLUTION: A Web server 21 of a transmission station 20 sends a file list denoting files which are to be sent by multiple-address communication to a reception state via a general public telephone network 60 (or satellite channel) before a file is sent to a plurality of reception stations 31, 32,..., 3n by multiple- address communication via a satellite 10. The transmission station 20 confirms that the corresponding reception state receives the file list, and then it sends the file by multiple-address communication via a satellite channel. Each of the reception stations 31, 32,..., 3n compares the received file with the file list to surely recognize whether or not the reception of the file is finished. When the reception is not finished, each reception station makes a request to the transmission state 20 for re-transmission of the file via the general public telephone network 60. |
