| 摘要 |
A method and system for detecting analog and Adaptive Differential Pulse Code Modulation ("ADPCM") communication links in a communication channel is described. On an illustrative embodiment, the method include the steps of transmitting a signal with a D.C. offset value across the communication channel, receiving the transmitted signal from the communication channel and detecting the D.C. offset value in the received signal. If the D.C. offset value is detected, the communication channel is determined to be a digital end-to-end connection. If the D.C. offset value is not detected in the received signal, the communication channel includes analog or ADPCM connection links and is not suitable for all-digital communications. In illustrative embodiment, the device includes a transmitter capable of transmitting an offset transmit signal, a receiver capable of receiving the transmitted signal and logic capable of detecting an offset signal. The logic may include an integrator to receive the transmitted signal, an absolute value circuit to determine the absolute value of the integrator output, and a comparator to compare the absolute value of the integrator output to a threshold value. If the absolute value of the transmitted signal is greater than a threshold value, the offset is detected indicating the presence of a digital end-to-end transmission channel. If the absolute value of the integrator is less than a threshold value, the D.C. offset is not detected indicating the presence of an analog link in the transmission channel.
|
