Patent ID: 6078645
Filing Date: 2000-06-20
Classification: H04B

Abstract:
An apparatus for monitoring a first data stream transmitted by a first modem to a second modem and a second data stream transmitted by said second modem to said first modem, said first data stream and said second data stream transmitted full duplex on overlapping frequency bands, the apparatus comprising:a first input means for receiving said first data stream;a second input means for receiving said second data stream;a first echo canceler connected to said first input means for canceling an echo resulting from said second data stream present in said received first data stream, thereby providing an echo free first data stream;a second echo canceler connected to said second input means for canceling an echo resulting from said first data stream present in said received second data stream, thereby providing an echo free second data stream;a first receiver for decoding said echo free first data stream and providing information decoded from said echo free first data stream;a second receiver for decoding said echo free second data stream and providing information decoded from said echo free second data stream;a first signal detector to detect start up sequences in said echo free first data stream and to report information detected from said echo free first data stream;a second signal detector to detect start up sequences in said echo free second data stream and to report information detected from said echo free second data stream;a first control unit communicatively connected to said first signal detector to receive said information detected from said echo free first data stream, said first control unit communicatively connected to said first echo canceler to control said first echo canceler and to train said first echo canceler during periods of half duplex operation of said first modem and said second modem with said second modem transmitting and said first modem receiving, said first control unit communicatively connected to said first receiver to control said first receiver and to receive information decoded from said echo free first data stream, said first control unit being able to identify which of said first and second modems is originate modem and which of said first and second modems is answer modem;a second control unit connected to said second signal detector to receive said information detected from said echo free second data stream, said second control unit communicatively connected to said second echo canceler to control said second echo canceler and to train said second echo canceler during periods of half duplex operation of said first modem and said second modem with said first modem transmitting and said second modem receiving, said second control unit communicatively connected to said second receiver to control said second receiver and to receive information decoded from said echo free second data stream, said second control unit being able to identify which of said first and second modems is originate modem and which of said first and second modems is answer modem, said second control unit communicatively connected to said first control unit to exchange between said first control unit and said second control unit said information detected from said echo free first data stream and said echo free second data stream, and said information decoded from said echo free first data stream and from said echo free second data stream, said second control unit being able to determine transmission parameters of said first and second modems and channel characteristics of channels connecting said first and second modems.