Modem with received signals and transmitted signals comprising signal sets
US5406583A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 21, 1993 |
| Grant date | Apr 11, 1995 |
| Priority date | — |
| Expiry date | Jun 21, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/06
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An approach for operating modems in synchronism with the A/D and D/A converters of the network limits the analog signals transmitted to the modem to low levels and concurrently restricts the received signals to large steps. This set of apparently conflicting signal limitations is achieved with a signal conversion process interposed in the communication path between the two hybrids. In one embodiment of this invention, the code conversion is implemented in an adjunct processor that is associated with a switch that participates in the communication path between the two modems. In operation, a call that needs the conversion process is identified by virtue of the calling party's number and service associated service provision information. When it is established that both the calling party's modem and the receiving party's modem operate in the manner that requires signal conversion, conversion is executed. Echo cancellation may be applied to the signal in the code conversion apparatus to further improve performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.