| 摘要 |
<p>A bi-directional interface apparatus 40 for a broadband or CATV network is disclosed. The interface unit 40 includes signal direction separators 50 and 50 which may be filters, a downstream amplifier 52 and an upstream amplifier 54. The apparatus also includes a signal detector 56 positioned in the upstream path before the input of amplifier 54. The signal detector 56 acts to switch power 60 to amplifier 54 dependent on the level of a detected upstream signal. The detector may have a logarithmic characteristic. The amplifier may become operative in less than 160ns. When there is no upstream signal from the subscribers home to the CATV network, amplifier 54 is turned off. The ingress of noise to the CATV network is thus prevented. Switching the amplifier off also reduces power consumption.</p> |
