A SELF-TALKING DETECTOR FOR ECHO CANCELLING MODEMS
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2001-Dec-12
Self-talk is an abnormal operation that may occur in 2-wire echo cancelling modems. It is caused by a sudden line disconnection. When the modem is oper- ating under a mild channel condition, the receiver may not recognize a sudden line drop and may continue its operation based on the near end echo signal, i.e., the transmitted data will be received. Unfortunately, it usually takes quite a long. time (usually several min- utes) for the modem to recognize the line drop. There- fore, it is highly desirable for the modem to have a fast self-talking detector so as to minimize the time inter- val in this mode.