Call progress decoder for multiple cadenced tones on telephone lines
US5483593A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 1993 |
| Grant date | Jan 9, 1996 |
| Priority date | — |
| Expiry date | Nov 1, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q1/30
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Apparatus for detecting single and/or multiple cadenced tone progress status of a telephone call in any one of a plurality of telephone networks is disclosed. A set of parameters for each of a multiplicity of predetermined single and/or cadenced tones in which some call progress status having multiple different sets of parameters for the same call progress status are stored in memory. Parameters of the cadence (s) of a valid tone present on the telephone line are measured and compared with the multiplicity of sets of parameters stored in the memory to establish the presence of the call progress status represented by the corresponding cadenced valid tone. For tones having multiple cadences, the measured parameters of each cadence is compared with a corresponding set of cadence parameters of the memory to establish the presence of the call progress status represented by the multiple cadenced tone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.