| 摘要 |
<p>In a communications network, a signal enhancement function, such as boosting the level of speech signals in the bassband (100 Hz - 300 Hz) is carried out by function processors (306) at various points in the network. To make sure that the enhancement function is carried out only once for any given signal, a signalling link, such as a 20 Hz subsonic signal, is added to the signal (308) downstream of the function processor. An incoming signal is passed through the function processor only if the signalling link is not detected in it (302,304). <IMAGE></p> |
