| 摘要 |
<p>A terrestrial flight telephone system comprises a number of air stations (1) which communicate on a common frequency with a ground station (11). The ground station can handle calls from a number of air stations (1) in respective slots of sequential frames defined by the ground station (11). Accurate synchronisation is critical to the functioning of the system and drift in an oscillator (5) of the air station (1), which controls the timing of transmissions from the air station, is corrected by signals received from the ground station (11). <IMAGE></p> |
