| 摘要 |
PROBLEM TO BE SOLVED: To provide a reception device which receives a beacon signal of a single frequency and makes switching control of a received frequency unnecessary when hand-over is performed. SOLUTION: A quasi-zenith satellite 310 stops a beacon signal 7 during transmission, and a quasi-zenith satellite 320 starts transmission of a beacon signal 8. Thus, the signal is handed over from the quasi-zenith satellite 310 to the quasi-zenith satellite 320. In this case, the frequency of the beacon signal 7 is the same as that of the beacon signal 8. For preventing interference, a first earth station 30 transmits a stop command to the quasi-zenith satellite 310 and stops transmission of the beacon signal 7. A second earth station 30a transmits a transmission start command to the quasi-zenith satellite 320 and starts transmission of the beacon signal 8. Hand-over is performed without the problem of interference even if the beacon of the same frequency is used by the command from the earth station. The reception device 100 can switch the tracking satellite to the quasi-zenith satellite 320 only by receiving the beacon of a single frequency. COPYRIGHT: (C)2005,JPO&NCIPI
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