| 摘要 |
PURPOSE:To automatically switch a system to the other satellite communication line when one satellite communication line breaks down without providing a TDMA alarm signal line by transmitting a specified pattern to an earth network. CONSTITUTION:When the satellite communication line is not used or it breaks down, satellite communication TDMA devices 11 and 12 transmit the specified pattern (non-call pattern, for example) to the earth network. A connection circuit 3 switches the satellite communication TDMA device 11 and the satellite communication TDMA device 12 at every channel by the detection of the non- call pattern and transmits the pattern to an earth network transmission device. Thus, the TDMA alarm signal line between the satellite communication TDMA devices 11 and 12 and the connection circuit 3 can be eliminated and the system can automatically be switched to the other satellite communication line when one satellite communication line breaks down. |
