Conference circuit with digital-analog and analog-digital conversion

US4160878A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Peter Hirschmann · Puchheim, DE
• Ernst Hoefer · Munich, DE

Key dates

• Filing date: Jul 19, 1978
• Grant date: Jul 10, 1979
• Expiry date: Jul 19, 1998

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04M3/561
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A circuit arrangement is disclosed for converting digital signals into analog signals and analog signals into digital signals. The circuit arrangement is used as a conference set for use by individual subscribers on a multiplex line. Digital signals of all subscribers are consecutively converted into analog signals and an analog summation signal is formed therefrom. This summation signal is again converted back into a digital signal and can be multiply transmitted as such. Alternatively, a number n of circuit arrangements are provided for a maximum number n of subscribers. Each of the circuit arrangements converts digital signals of n-1 conference subscribers (excluding an allocated subscriber) into analog signals and forms an analog summation signal therefrom. This analog summation signal is converted back into a digital signal which is transmitted in a time slot allocated to the allocated conference subscriber to which the circuit arrangement is allocated.