Rate negotiation for variable-rate digital subscriber line signaling
US5999563A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1996 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Oct 31, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2025/03611
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A modem that operates selectively in the voice-band frequency band and at higher frequency bands is provided. This modem supports multiple line codes, like DMT and CAP. The modem uses a Digital Signal Processor (DSP), so that different existing ADSL line codes, such as Discrete MultiTone (DMT) and Carrierless AM/PM (CAP), can be implemented on the same hardware platform. The modem negotiates in real-time, for a desired line transmission rate to accommodate line condition and service-cost requirement. The line code and rate negotiation process may be implemented at the beginning of each communication session through the exchange of tones between the modems. A four-step MDSL modem initialization process is provided for line code and rate compatibility.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.