Method for reducing noise from an asymmetric digital subscriber line modem
US6721394B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1999 |
| Grant date | Apr 13, 2004 |
| Priority date | — |
| Expiry date | Dec 9, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/18
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method for reducing audible noise in a telephone from a splitterless asymmetric digital subscriber line modem. The modem examines the shape of the power spectrum of fast retrain signals both when the telephone is on-hook and off-hook. By comparing the spectra, in particular the slopes of the spectra, the modem may determine the quality of the telephone that shares the telephone loop with the modem. The modem cuts back its transmitted power depending on the quality of the telephone by an amount that suppresses the audible noise in the telephone. In this manner, a customer may simultaneously use the telephone and the modem on the same telephone loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.