Far-end disconnect detector for telephony systems
US5479501A · kind A · utility
30Cited by
10References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 8, 1993 |
| Grant date | Dec 26, 1995 |
| Priority date | — |
| Expiry date | Oct 8, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q1/44
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for detecting a far-end disconnect signal for use by telephony applications such as voice messaging systems. In a preferred embodiment of the present invention, signal power of a telephone signal in particular frequency ranges is compared with the signal power in these frequency ranges for characteristic far-end disconnect signals used by telephone systems worldwide. Further, the cadence of the signal power of the telephone signal is examined to determine whether the cadence of the telephone signal is characteristic of far-end disconnect signals, including "busy signals" and "dial tones."
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.