Method and apparatus for checking the integrity of a communications channel in a voice store and forward system
US4580016A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 1984 |
| Grant date | Apr 1, 1986 |
| Priority date | — |
| Expiry date | Sep 24, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/28
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for determining the integrity of a communications channel includes a first communications system connected to a communications channel with a receiving communications system attached to the other end of the chennel. The first communications system generates a discrete frequency at the low end of the bandwidth for reception by the receiving system. The receiving system measures the frequency and the power level of the first tone. The first communications system then inhibits transmission for a predetermined duration of time during which the receiving system measures the noise floor of the communications channel. A second tone is then generated at the high end of the channel bandwidth for reception by the receiving system. The receiving system then compares the measured power levels of the first and second tone and the noise floor with predetermined criteria and determines the integrity of the communications channel from this comparison. If the integrity meets a prescribed level, voice messages are transmitted from the first communications system to the receiving communications system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.