Signal-type dependent real-time fax relay
US7733848B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 25, 2005 |
| Grant date | Jun 8, 2010 |
| Priority date | — |
| Expiry date | Apr 8, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2212/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In order to enable V.34 fax relay communications over IP (“FoIP”) without increasing a gateway complexity, the gateway relays all types of fax control signals in demodulated form and transfers fax image type signals either as demodulated or as PCM encoded signal, based on a predetermined condition. The PCM data type is added to FoIP protocol to allow transferring PCM encoded fax image signals without exiting from FoIP mode of operation until the completion of a fax call. During a FoIP call, the communicating gateway determines whether the input fax signal is a ‘fax control signal’ or a ‘fax image’ type signal. If the gateway determines that the input signal is a fax control signal or supported fax image signal, it handles it in a traditional fax relay manner. However, if the gateway determines that the input fax image type signal cannot be demodulated, it outputs the fax signal to the IP network as PCM encoded signal and without performing demodulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.