| 摘要 |
<p>In the present invention, a single-frequency tone is used as addressing header for each optical packet (26). The frequency of the single-frequency tone is situated within the baseband of the digital payload signal and is preferably a radio-frequency tone. The single-frequency tone is multiplexed with teh digital payload and modulated into an envelope of an optical carrier. The frequency is indicative of an address or out-port (34, 36) for the optical packet (26), which means that different destinations in the network correspond to different frequencies. When switching such an optical packet, the power of the frequency tone (fj, fk) is measured. If a tone is present, the optical path corresponding to the allocation is opened by an electronic switch control (46), and when the tone disappears, the path is closed. Due to the narrow bandwith of the frequency tone, any disturbance of the digital payload is essentially negligible.</p> |
