| 摘要 |
<p>A system for providing echo control for voice calls transmitted over circuit switched and packet switched networks uses stand-alone echo cancellers. A first echo canceller (310) is coupled to a first switch (130) in the circuit switched network and a first gateway (150) on the packet switched network. The first gateway forwards a first voice call over the packet switched network(170) to a second gateway (160) . The second gateway forwards the first voice call to a second switch (140) on the circuit switched network. A second echo canceller (320) is coupled to the second gateway and the second switch. The second echo canceller cancels echo associated with the first voice call when time associated with transmitting a first voice signal is greater than or equal to predetermined threshold.</p> |
