Apparatus and method for monitoring full duplex data communications
US6078645A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1997 |
| Grant date | Jun 20, 2000 |
| Priority date | — |
| Expiry date | Feb 20, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/23
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A modem monitor for monitoring full duplex communications comprises one receiver for each data stream and an echo canceler for canceling "far" echo. Prior to each receiver decoding the data stream it is designed to monitor, it replicates an echo expected to be found in its received data stream from a sample of each of the other predecoded data streams. The echo canceler then subtracts the expected echo from the received data stream to remove all far echoes caused by the other data streams. The echo canceled data stream is then decoded. The monitor can also include a data communications network interface and a sample rate converter operating with the PSTN for converting from the network transmission rate to the data transmission rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.