Apparatus and method for improved DSL communication
US6192109A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1998 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | Dec 23, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/50
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention is generally directed to an xDSL modem that is capable of transmitting at multiple data rates. Specifically, the xDSL modem is configured to generally transmit at a high data rate (typically the highest data rate supported by the line), but will reduce its data transmission rate in response to one or more sensed conditions. In this regard, it has been found that transmitting at a data rate that is low enough to avoid significant corruption, and thus retransmission, achieves a higher overall data transmission rate than that which is achieved if re-transmissions are required. Further, various conditions may be sensed that will prompt the xDSL modem to alter its transmission rate, including detecting an unfiltered POTS device going Off-Hook. In accordance with one aspect of the present invention, at modem startup, the Off-Hook condition and other line problems are detected by direct measurement of the line impedance. Given a first impedance measurement in which the impedance is approximately equal to the impedance of the typical twisted-pair loop, the digital signal processor (DSP) of the present invention is able to detect that either all phones are on hook or t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.