Method of determining answer supervision at a line appearance of a public switch telephone network
US6810120B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 2000 |
| Grant date | Oct 26, 2004 |
| Priority date | — |
| Expiry date | May 15, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/2272
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Audible ring, which is provided to all line appearances, is detected and used to determine whether or not a far end party has answered, i.e., answer supervision, for equipment connected to the line appearance which requires answer supervision for proper operation. The line appearance is monitored to detect ringing tone received at the line appearance within a first period of time from call origination. If ringing tone is not detected at the line appearance within the first period of time, receipt of answer supervision is indicated. If ringing tone is detected at the line appearance within the first period of time, the timing for the first period of time is canceled and timing for a second period of time is started from the cancellation of timing for the first time period. The timing for the second period of time is restarted each time ringing tone is detected at the line appearance during the second period of time with receipt of answer supervision being indicated if ringing tone is not detected within the second period of time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.