| 摘要 |
The system includes an exchange (1) and terminals (3,4) each having a laser transmitter (5,7) and modulator (6,8), connected via a fibre-optic network (2). Each modulator restricts the emission of light from its laser to successive time slots which are separated by longer intervals. During a transmission time slot the modulating waveform may be either a half-sinewave, a ramp or a square-wave. The repetition frequency of this waveform differs from one terminal to the other. |
