Method and apparatus providing data communication over an existing telephone network without interfering with normal telephony functions
US6330235A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1997 |
| Grant date | Dec 11, 2001 |
| Priority date | — |
| Expiry date | Nov 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/064
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and an apparatus for providing data communications over the existing telephone network without burdening the public switched telephone network (PSTN) switch with data communications traffic. In one embodiment, a novel modem is coupled to both ends of the twisted pair telephone wire which runs between a remote location and the Central Office (CO) or the remote CO. An off-hook detector is also connected to the twisted pair line in order to enable detection of when normal telephony functions are being performed over the twisted pair line. The modems of the present invention are capable of transmitting data whenever normal telephony functions are not being performed, such as for example when the telephone line is on-hook. The data transmission in accordance with the teachings of the present invention uses sufficiently low current levels such that the PSTN switch located at the CO does not detect any activity on the twisted pair line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.