| 摘要 |
A method of detecting control tones in a digital signal by using a tone detection unit (11) (TDU) and a packet voice protocol unit (12) (PVPU) in a network over which the signal is transmitted. The TDU (11) detects the presence of a control tone in the signal within the first 5 ms of transmission and generates an alert signal (23) to the PVPU (12) to cease further transmission of the signal. Upon confirmation, the PVPU (12) may halt the transmission and buffer or delete the voice signal packets. Alternatively, if the control tones are not present in the signal, the PVPU (12) may continue transmission of any buffered packets. The method further incorporates the sending of the control tone signal to the receiving end of the transmission of the voice packets following transmission of the control tone to the receiving end. |
