Multiplex communications – Wide area network – Packet switching
Patent
1989-04-03
1990-11-13
Ng, Jin F.
Multiplex communications
Wide area network
Packet switching
379410, H04B 323
Patent
active
049707159
ABSTRACT:
A modem capable of simultaneously transmitting and receiving data signals over a single communication channel with a remote modem includes a transmitter for converting TX digital data into analog signals for transmission over the channel and a receiver for converting received analog signals into RX digital data. A mechanism identifies a remote echo returning to the modem corresponding to previously transmitted TX digital data. The identifiying mechanism is capable of identifiying a echo originating intermediate between the modem and the remote modem. Another mechanism substantially cancels the identified remote echo. The present invention also encompasses the method of identification and cancellation of remote echos. In addition, remote echo cancellation signals are not combined with received signals until local echo has been substantially cancelled.
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Ng Jin F.
Universal Data Systems, Inc.
Vaas Randall S.
Warren Charles L.
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