Patents by Inventor Hans P. Staab

Hans P. Staab has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method and apparatus for adaptive receiver squelch echo control
    Patent number: 4694450
    Abstract: After receipt of the answerback tone in a conventional handshaking procedure, the originate modem is connected to the communication line, sends a short echo control training (ECT) sequence to the answer modem, and starts a timer. Upon receipt of the ECT.sub.o sequence, the answer modem sends its own ECT.sub.a sequence to the originate modem and starts its own timer. Upon receiving the ECT.sub.a sequence, the originate modem measures the round trip propagation delay (T.sub.RTPD) and transmits a second ECT.sub.o sequence. The time of receipt of this sequence at the answer modem is used by the answer modem to determine T.sub.RTPD. Either modem may now start data transmission. Because of the measurements made, the receiver at the transmitting modem is aware that the echo from its transmission will be delayed by T.sub.RTPD. Accordingly, it will open an "echo monitor window" in a time interval around T.sub.RTPD during which time frame any received energy is assumed to be an echo.
    Type: Grant
    Filed: May 31, 1984
    Date of Patent: September 15, 1987
    Inventor: Hans P. Staab