Preventing double digit detection caused by in-band dual-tone multi-frequency signaling
US9762740B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 10, 2014 |
| Grant date | Sep 12, 2017 |
| Priority date | — |
| Expiry date | May 3, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L47/56
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A T2P (TDM to packet) delay buffer is provided. The delay buffer can prevent double digit detections caused by in-band DTMF leak when out-of-band DTMF is used. The T2P delay buffer is initialized with an audio pattern that represents silence in a configurable amount of delay. When a DTMF digit is detected, the system can stop taking the voice payload from the T2P delay buffer and start injecting RFC4733 RTP packets into the RTP stream at a pre-configured rate. The RFC4733 DTMF RTP packets continue to be injected into the RTP stream until the DTMF digit stops. Once the end of the DTMF digit is detected, the content of the T2P delay buffer can be discarded and the T2P delay buffer is reinitialized with an audio pattern that represents silence in a configurable amount of delay. After the T2P delay buffer is reinitialized, the voice packetization can be continued.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.