Speech path switching control apparatus and method for making maintenance of speech possible upon occurrence of fault in echo cancellation
US5511064A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1994 |
| Grant date | Apr 23, 1996 |
| Priority date | — |
| Expiry date | Oct 18, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/244
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Speech path switching control apparatus and a method for making maintenance of speech possible even upon occurrence of a fault in echo cancellation. The speech path switching control apparatus includes a time switch for receiving PCM voice data from a space switch through a switch network link and performing time slot interchange with trunk lines, an echo canceller connected to the time switch through a plurality of sub-highways to cancel echoes, an access switching processor for discriminating whether echo cancellation is required for a trunk call allocated with a particular one of the trunk lines and outputting the resultant discrimination signal, and a time switch control processor for controlling the time switch and the echo canceller in response to the discrimination signal from the access switching processor. If the echo cancellation is not required or the echo canceller is abnormal, there is formed a speech path which is not passed through the echo canceller. In the case where the echo cancellation is required and the echo canceller is normal, there is formed a speech path which is passed through the echo canceller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.