Channel switching unit for a telephone switching center and switching arrangements utilizing such units
US4024350A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1975 |
| Grant date | May 17, 1977 |
| Priority date | — |
| Expiry date | Oct 30, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q11/02
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The switching unit comprises for two-way transmission two branches, each of which includes in series an input mixer, a channel filter and an output mixer, and two variable frequency digitally controlled carrier current generators, the first of which feeds the input mixer of the first branch and the output mixer of the second branch, and the other of which feeds the output mixer of the first branch and the input mixer of the second branch. In a switching arrangement using such units, a telephone channel can be transferred from an incoming multiplexed group to an outgoing multiplexed group by means of two units whose second generators receive a common frequency, while their first generators respectively receive frequencies corresponding to the positions of the considered channel in the incoming and outgoing groups respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.